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Where things may lie:
An investigation into artefact patterning from within a coastal marine deposit,
Holdfast Bay, South Australia.
Christopher Lewczak
Thesis submitted in fulfilment of a degree in Bachelor of Archaeology (Honours)
Department of Archaeology
School of Humanities
The Flinders University of South Australia
2000
I hereby waive the following restrictions:
a) For three years after the deposit of the thesis, readers other than academic
staff and students of the University must obtain the consent of the Author or
the Head of the Discipline or the Librarian before consulting a thesis;
b) For three years after the deposit of the thesis, no copy may be made of the
thesis or part of it without prior consent of the author.
NAME:
……………………….………….
SIGNATURE: …………………………………..
DATE:
…………………………………..
The work presented in this thesis is, to the best of my knowledge and belief original
except where acknowledged in the text. The material has not been submitted in whole
or part for a degree at this or any other university.
_______________________
Christopher Lewczak
ii
Abstract
In February 2000 the Society for Underwater Historical Research conducted and
excavation on the original jetty located at Holdfast Bay. During this excavation the
location of the artefacts uncovered were recorded in three dimensions, allowing for a
unique opportunity to investigate their positioning. This thesis questions the ordering of
the artefacts within the deposits at Holdfast Bay and researches the potential for artefact
patterning.
During this investigation it was discovered that the artefacts were not positioned in
chronological order. Further testing of the data, as well as understanding the mechanics
of the environmental influences at Holdfast Bay, revealed that, while little support was
found, the potential for artefact patterning was highlighted with suggestions for future
directions.
iii
Acknowledgments
There are many people that I would like to thank for their time, patience, and support.
Firstly, without the support and the latitude that was bestowed upon me from my
supervisors, Dr Mark Staniforth and Dr Bill Adams none of this would have been
possible. Without the Society for Underwater Historical Research, its members and the
time that they put into the Holdfast Bay project, this thesis would not exist.
In
particular, I would like to thank Nathan “Nugget” Richards for being the Director of the
Holdfast Bay Project, in allowing me to stay at his humble abode during the project, and
for all the times that he came to the rescue in the production this thesis.
I would also like to show my appreciation to all of the people that helped care and
conserve the artefacts while they were sitting at Neatly. Also I would like to thank
Heritage South Australia for allowing me to use their space in conducting some of this
research. Without their support I would have been sleeping next to the artefacts while
they were being treated. To all other members of the Archaeological staff at Flinders
University, especially Matt Schlitz for the time spent in fine tuning aspects of the
photography.
To my parents, for whom without none of this research, nor any of the words would
have been written in the first place. To my brother Matt, his skills as a photographer
and as a brother were invaluable.
To Ashley Matic, all of those long hours spent both working on thesis and the twice as
many away from it, they were times that will never be forgotten.
Susan Marie Briggs, there are time when words can not explain how much of a help you
have been to me, but I feel that you understand me still.
iv
Contents
INTRODUCTION……………………………………………………………………………………...1
A BRIEF HISTORY OF HOLDFAST BAY JETTY. .......................................................................................... 2
ARCHAEOLOGY ON THE HOLDFAST BAY JETTY. ...................................................................................... 7
HOLDFAST BAY 2000 FIELDWORK AND METHODOLOGY ....................................................................... 10
CATALOGUING AND CONSERVATION ..................................................................................................... 14
METHODOLOGY. .................................................................................................................................... 16
THESIS OUTLINE .................................................................................................................................... 19
1.
LITERATURE REVIEW .............................................................................................................. 21
CASE STUDIES ........................................................................................................................................ 22
OTHER THEORY AND PRACTICAL WORK ................................................................................................. 28
DISCUSSION: .......................................................................................................................................... 40
2.
ENVIRONMENTAL FORCES ACTING IN COASTAL ZONES AND IN THE HOLDFAST
BAY ENVIRONMENT. .......................................................................................................................... 46
ENVIRONMENTAL FORCES. ..................................................................................................................... 46
Wind.................................................................................................................................................. 48
Tides ................................................................................................................................................. 52
Currents ............................................................................................................................................ 55
FLORAL AND FAUNAL INFLUENCES. ....................................................................................................... 57
DISCUSSION ........................................................................................................................................... 59
3.
GENERAL ANALYSIS OF THE MATERIAL........................................................................... 63
FABRIC ................................................................................................................................................... 64
COMPLETENESS ...................................................................................................................................... 64
FUNCTION .............................................................................................................................................. 65
CONDITION............................................................................................................................................. 68
DIAGNOSTIC ARTEFACTS AND SPECIAL FINDS ....................................................................................... 69
4.
THE QUESTION OF CHRONOLOGY ON THE SITE. ........................................................... 71
DISCUSSION ........................................................................................................................................... 76
CONCLUSION .......................................................................................................................................... 79
5.
RESULTS AND ANALYSIS OF ARTEFACT PATTERNING: DENSITY............................. 82
Area E. .............................................................................................................................................. 83
Area F ............................................................................................................................................... 88
Area G .............................................................................................................................................. 94
DISCUSSION ........................................................................................................................................... 98
CONCLUSION ........................................................................................................................................ 103
6.
RESULTS AND ANALYSIS OF PATTERNING: MATERIAL TYPE.................................. 104
Overview of Three Areas together .................................................................................................. 106
Area E ............................................................................................................................................. 111
Area F ............................................................................................................................................. 114
Area G ............................................................................................................................................ 120
DISCUSSION ......................................................................................................................................... 125
7.
ANALYSIS AND RESULTS OF PATTERNING: COINS. ..................................................... 130
DISCUSSION ......................................................................................................................................... 134
8.
DISCUSSION ................................................................................................................................ 136
POTENTIAL FOR FURTHER RESEARCH. .................................................................................................. 144
9.
CONCLUSION ............................................................................................................................. 146
v
List of Figures
FIGURE 1: LOCATION OF GLENELG, HOLDFAST BAY (SOURCE ENCARTA 1998). .......................................... 2
FIGURE 2: AN EARLY PROPOSAL OF A JETTY TO BE BUILT AT HOLDFAST BAY. (MORTLOCK LIBRARY B342).
............................................................................................................................................................ 3
FIGURE 3:TWO EARLY VIEWS OF THE ORIGINAL JETTY, 1875 (LEFT) AND LATER IN 1880 (RIGHT).
(MORTLOCK LIBRARY B 7335 AND B 12570)...................................................................................... 3
FIGURE 4:AN OFTEN CROWDED GLENELG BEACH AND JETTY, 1896 (MORTLOCK B7584 AND B7586) ......... 4
FIGURE 5: THE TWO POPULAR ADDITIONS TO THE HOLDFAST BAY JETTY, THE PAVILION/TEA ROOMS IN 1908
(LEFT) AND THE AQUARIUM IN 1929 (RIGHT) (MORTLOCK LIBRARY B19615 AND B5473) ................. 5
FIGURE 6: THE DAY AFTER A STORM DESTROYED THE HOLDFAST BAY JETTY, 1948 (MORTLOCK LIBRARY
B21596). ............................................................................................................................................. 6
FIGURE 7: EXCAVATION TECHNIQUES USED DURING THE 1974-78 HOLDFAST BAY EXCAVATION.
(PHOTOGRAPH T. DREW) ..................................................................................................................... 8
FIGURE 8: MAP SHOWING THE LOCATION OF THE AREA EXCAVATED BETWEEN 1974-78 (FROM DREW 1983,
P.6). ..................................................................................................................................................... 9
FIGURE 9: AN EXAMPLE OF THE METHOD USED TO RECORD WHERE ARTEFACTS WERE FOUND DURING THE
1974-78 EXCAVATION. (ADAPTED BY N. RICHARDS), ....................................................................... 10
FIGURE 10: ARIEL PHOTOGRAPHY SHOWING THE SITE AND LOCATION OF THE TRENCHES THAT WERE
EXCAVATED. ...................................................................................................................................... 11
FIGURE 11: AN EXAMPLE OF THE LABELS USED TO IDENTIFY EACH STAKE. (PHOTOGRAPH BY K. BROWN) 12
FIGURE 12: OPERATING THE HEAD OF THE AIR DREDGE (LEFT) AND RECORDING IN OPERATION (RIGHT)
(PHOTOGRAPH K. BROWN). ............................................................................................................... 13
FIGURE 13: CONSERVATION WORK BEING CARRIED OUT BY TWO OF THE MANY DEDICATED SUHR
MEMBERS. ......................................................................................................................................... 15
FIGURE 1.1: LOCATION OF MANDAL AND MOVIK HARBOUR, NORWAY (SOURCE ENCARTA 1998). ........... 23
FIGURE 1.2: LOCATION OF KINSHASA, DEMOCRATIC REPUBLIC OF CONGO (SOURCE ENCARTA 1998). ..... 24
FIGURE 1.3: THE SHIP WRECKING PROCESS ACCORDING TO MUCKELROY (MUCKELROY 1978, P.157) ....... 31
FIGURE 1.4: EDITED VERSION OF MUCKELROY'S SHIPWRECKING PROCESS BY WARD ET AL (AFTER WARD
ET AL 1999). ...................................................................................................................................... 35
FIGURE 2.1: LOCATION OF THE DIFFERENT COASTAL ZONE AREAS. (ADAPTED FROM DAVIS 1985, P.386). 47
FIGURE 2.2: WINDS EXPERIENCED DURING SPRING AND SUMMER OVER ADELAIDE AND HOLDFAST BAY.
RECORDED AT ADELAIDE AIRPORT (SOURCE WWW.BOM.GOV.AU/SA/FORCASTS.SHTML) ................. 50
FIGURE 2.3: WINDS EXPERIENCED DURING AUTUMN AND WINTER OVER ADELAIDE AND HOLDFAST BAY.
RECORDED AT ADELAIDE AIRPORT. (SOURCE WWW.BOM.GOV.AU/SA/FORCASTS.SHTML) ................ 51
FIGURE 2.4: MOVEMENT OF WATER PARTICLES INSIDE A WAVE. ................................................................. 54
FIGURE 2.5: CURRENTS FORMED FROM A SOUTHWESTERLY WIND (ADAPTED FROM TRONSON 1973)......... 56
FIGURE 2.6: CURRENTS FORMED FROM A NON-SOUTHWESTERLY WIND. (ADAPTED FROM TRONSON 1973)
.......................................................................................................................................................... 56
FIGURE 2.7: AN EXAMPLE OF BURROWS THAT CAN DISTURB AS SITE. (ADAPTED FROM FERRARI AND ADAM
1990, P.140) ...................................................................................................................................... 58
FIGURE 3.1: COUNT OF ARTEFACTS FROM EACH AREA EXCAVATED ........................................................... 63
FIGURE 3.2: SUMMARY OF ARTEFACTS SHOWING FABRIC FROM ALL EXCAVATED AREAS. .......................... 64
FIGURE 3.3: COMPLETENESS OF ARTEFACTS EXCAVATED FROM HOLDFAST BAY, 2000. ........................... 65
FIGURE 3.4 COUNT OF FUNCTIONS ASSOCIATED WITH THE MATERIAL. ....................................................... 66
FIGURE 3.5 A SELECTION OF BUILDING MATERIALS UNCOVERED FROM UNDER THE PAVILION/TEAROOMS.
.......................................................................................................................................................... 67
FIGURE 3.6: A SAMPLE SHOWING THE VARIETY OF ARTEFACTS UNCOVERED FROM UNDER THE ORIGINAL
JETTY. ............................................................................................................................................... 67
FIGURE 3.7: EXAMPLE OF THE DIFFERENT CONDITIONS OF GLASS UNCOVERED........................................... 68
FIGURE 3.8: EXAMPLE OF DIFFERENT CONDITION OF THE COINS UNCOVERED AT HOLDFAST BAY .............. 68
FIGURE 3.9: CONDITION OF THE ARTEFACTS (EXCLUDING COINS). .............................................................. 69
FIGURE 3.10: THE ONLY TWO INTACT BOTTLES FOUND ON SITE ................................................................. 70
FIGURE 4.1: MAP OF LOCATION OF THE AREAS E, F AND G. ....................................................................... 71
FIGURE 4.2: POSITION OF THE EIGHT COINS FROM ALL THREE TRENCHES NEXT TO EACH OTHER................. 72
FIGURE 4.3: J. LADD BOTTLE FRAGMENT UNCOVERED FROM A DEPTH OF 40CM, TRENCH E2. .................. 73
FIGURE 4.4: THE THREE COINS THAT WERE UNCOVERED FROM AREA F'S TRENCHES ................................... 74
FIGURE 4.5: POSITION OF DIAGNOSTIC GLASS FRAGMENTS AGAINST COINS FOUND IN AREAS E, F AND G... 75
vi
FIGURE 4.6: THREE OF THE DIAGNOSTIC GLASS FRAGMENT UNCOVERED FROM AREA G. ........................... 76
FIGURE 5.1: AN EXAMPLE OF AN ARTEFACT PATTERN FORMED BY THEIR DENSITIES THAT KELLER BELIEVES
COULD BE CREATED IN UNCONSOLIDATED SEDIMENTS. ..................................................................... 83
FIGURE 5.2: THE DEPTH AND DENSITY OF ARTEFACTS LOCATED IN TRENCH E1.......................................... 84
FIGURE 5.3: DEPTH AND DENSITIES OF ARTEFACTS FROM TRENCH E2. ...................................................... 87
FIGURE 5.4: DEPTH AND DENSITY OF ARTEFACTS FROM TRENCH F1........................................................... 88
FIGURE 5.5: DEPTHS AND DENSITIES OF ARTEFACTS FROM TRENCH F2. ..................................................... 89
FIGURE 5.6 LOCATION OF THE THREE SECTIONS SHOWING THE DIFFERENCE BETWEEN THEIR HIGHEST AND
LOWEST DENSITIES ............................................................................................................................ 90
FIGURE 5.7: DEPTHS AND DENSITIES OF ARTEFACTS FROM TRENCH F3. ..................................................... 93
FIGURE 5.8: DEPTHS AND DENSITIES OF ARTEFACTS FROM TRENCH G1. ..................................................... 95
FIGURE 5.9: DEPTHS AND DENSITIES OF ARTEFACTS FROM TRENCH G2. ..................................................... 97
FIGURE 6.1: COUNT OF MATERIAL TYPES FROM ARTEFACTS UNCOVERED IN AREAS E, F AND G. .............. 106
FIGURE 6.2: DEPTH AND FREQUENCY OF OBJECTS MADE OF METAL FROM AREAS E, F AND G. ................. 107
FIGURE 6.3: COUNT OF GLASS MADE OBJECTS FROM EACH DEPTH AREAS E, F AND G. ............................. 108
FIGURE 6.4: FREQUENCY OF BROWN GLASS OBJECTS FROM AREAS E, F AND G........................................ 108
FIGURE 6.5: COUNT OF CLEAR AND GREEN GLASS FRAGMENTS UNCOVERED FROM EACH DEPTHS. ........... 109
FIGURE 6.6: COUNT OF OBJECTS MADE FROM LEAD UNCOVERED FROM EACH DEPTH. ............................... 110
FIGURE 6.7: THE COUNT OF OBJECTS MADE FROM AN ALLOY UNCOVERED FROM EACH DEPTH. ................ 110
FIGURE 6.8: DEPTH AND MATERIAL TYPES OF ARTEFACTS FOUND FROM TRENCH E1. .............................. 112
FIGURE 6.9: DEPTH AND MATERIAL TYPES OF ARTEFACTS FROM TRENCH E2. .......................................... 113
FIGURE 6.10:DEPTH AND MATERIAL TYPES OF ARTEFACTS FROM TRENCH F1. ......................................... 115
FIGURE 6.11: DEPTH AND MATERIAL TYPES OF ARTEFACTS FROM TRENCH F2 ......................................... 116
FIGURE 6.12: DEPTH AND MATERIAL TYPES FROM TRENCH F2 SHOWING THE THREE DIFFERENT DEPTH
SECTIONS. ........................................................................................................................................ 117
FIGURE 6.13: DEPTH AND MATERIAL TYPE OF ARTEFACTS FROM TRENCH F3. .......................................... 119
FIGURE 6.14: DEPTH AND MATERIAL TYPE OF ARTEFACTS FROM TRENCH G1. ......................................... 121
FIGURE 6.15: ARTEFACT PHOTOGRAPH OF THE SHARPENING STONE (GJ 3019) AND SECTION OF A RUBBER
HEAL (GJ 3112). (PHOTOGRAPHS BY S. BRIGGS). ............................................................................ 122
FIGURE 6.16: DEPTH AND MATERIAL TYPE OF ARTEFACTS FROM TRENCH G2 .......................................... 124
FIGURE 7.1: POSITION OF COINS FROM AREAS E, F, AND G SHOWING THE DENSITY AND COIN TYPE.
(P=PENNY; HP=HALFPENNY; TP= THREE PENCE PIECE). ................................................................ 132
List of Tables
TABLE 3.1: COIN CONDITION. ..................................................................................................................... 69
TABLE 7.1: LIST OF COINS PRESENT IN THE AREAS E, F, AND G WITH THEIR CORRESPONDING DIAMETER
AND DENSITIES. ............................................................................................................................... 133
vii
Introduction
In 1972 Keller proposed that artefacts within marine deposits could settle according to
their densities. Since then no further research has examined the vertical movement of
artefacts in marine deposits. This is despite several articles examining similar
possibilities on land (Stockton 1973, Moeyersons and Cahen 1977).
The purpose of this thesis is to test Keller's (1972) hypotheses while drawing on the
above mentioned land-based studies and research of oceanographers regarding
environmental influences. Through this an advanced understanding of the processes
effecting shallow marine deposits will be developed. A better understanding of the
vertical movement of artefacts will have significant implications for the analysis of
marine deposits. To achieve this aim a case study is employed. The Holdfast Bay jetty
was excavated a second time by the Society for Underwater Historical Research in
January of 2000. The first excavation was held between 1974 and 1978. During this
most recent excavation all artefacts were measured in three dimensions, giving a rare
opportunity to analyses these artefacts in relation to their densities and material types.
Four specific questions were asked of the Holdfast Bay assemblage. Firstly, were the
deposits arranged in chronological order? Secondly, if not, could the deposits be
arranged by artefact density, thirdly, material type or fourthly, by a combination of these
attributes. The fourth question looked specifically at coins as they are identical in most
respects. These four hypotheses were proposed by Keller (1972) and while this thesis
identifies further attributes that may affect the movement of artefacts in deposits it is
outside the scope of this thesis to test them.
1
Figure 1: Location of Glenelg, Holdfast Bay (Source Encarta 1998).
A Brief History of Holdfast Bay Jetty.
Holdfast Bay, named because of its good anchorage, was the first European mainland
settlement in South Australia (Gibbs 1984, p.4). Since it was surveyed by Colonel
Light in 1836, there was always a plan for a jetty and breakwater to be built in the area.
The highest ambition for Holdfast Bay, held by Light himself, was that it would become
the official port of the colony of South Australia's (Perry 1985, p.15). These plans were
soon dashed with the opening of Port Adelaide in 1837 (Parsons 1982, p.10). Although
Holdfast Bay was considered a poor landing site due to the necessity of landing all
migrants on the beach, Port Adelaide was no better.
In addition to poor landing
facilities Port Adelaide was also plagued with large tidal flats, mud, mangroves, and
mosquitos (Whitelock 1977, p.49). Port Adelaide could offer shelter however, and in
1840 was named South Australia's international port (Brice 1977, p.14). Vessels were
then encouraged to bypass Holdfast Bay for Port Adelaide. This bypassing of Holdfast
Bay delayed the development of the foreshore for almost 20 years. It also had the effect
of shaping the area as a holiday destination. In 1839, 65 acres were set aside for the
establishment of a township, which was named after the colonial secretary for the South
Australia Company, Lord Glenelg. The township was sustained in the early years by its
2
boat building, fishing and tourism trade.
Tourism caused the major increase in
popularity of the area, and in 1843 there were no vacant rooms for rent anywhere in the
district during summer.
Figure 2: An early proposal of a jetty to be built at Holdfast Bay. (Mortlock Library B342).
This popularity of the township brought an increased number of inns. The increased
number of people visiting and staying at Glenelg attracted new shop. These shops
included a bake house, druggist, butcher, two schools, a smithy and a slaughterhouse
(Hignett & Co. 1983, p.11). The community was soon able to support the everyday the
needs of the residents (Hignett & Co. 1983, p.11).
Figure 3:Two early views of the original jetty, 1875 (Left) and later in 1880 (Right). (Mortlock
Library B 7335 and B 12570).
The growth in population and business' in Glenelg gave impetus to the plans of a jetty
and breakwater. The plans were also supported by the increasing number of vessels
3
visiting the area. R.B. Colly and the Glenelg Jetty Company set out to decide on the
plans for a jetty in the early 1850s. Nevertheless, it was not until 1855 that a design was
decided on.
All plans and materials for this jetty were ordered from England. The charter vessel to
bring the materials, Berkshire, ran aground off the coast of Brazil during the voyage.
Forced to drop 60 tonnes of iron piles into the water, the vessel still managed to bring
the remaining components of the jetty. This, however, resulted in the shortening of the
jetty (Parsons 1986, p.78-79). The Berkshire arrived in 1857 and later that year the first
pile was driven in. At a cost of £31, 294, the jetty was finished in 1859 (Jeans 1979,
p.150). At a length of 1,250 feet (381 metres), the jetty was made of iron piles and
Jarrah wood and was one of the first in the state.
Figure 4:An often crowded Glenelg beach and jetty, 1896 (Mortlock B7584 and B7586)
There were many additions to the jetty through out its life. The increasing number of
vessels stopping at the Bay led to an addition of a wooden lighthouse in 1872 (Lee
1883, p.14). A fire destroyed it, however, in 1873, nearly taking the rest of the jetty
with it. Repairs were made to the structure, which now included a "L" head pointing
northwards. A second lighthouse, iron this time, was installed in 1874 and a steam
crane was added to help load and unload vessels (Lee 1883, p.15).
4
The Jetty drew more people to Glenelg. A railway line was layed in 1873, and with
quick travel time, more people saw Glenelg as a day trip away from the city and as well
as a weekend retreat (McDougall & Vines 1988, p.9). Residential areas were planned
out, with many plots sold quickly with the introduction of gas and water pipes into the
area.
Vessels stopping at the new jetty brought mail, while people could go on day trips (Lee
1883, p.14). Passenger ships began stopping again, while crops grown in the area were
also being transported out of the state. The hulk, Harriet Hope, was moored close to the
jetty, and acted as a coal hulk from the P&O Company (Perry 1985, p61).
Figure 5: The two popular additions to the Holdfast Bay jetty, the pavilion/tea rooms in 1908 (left)
and the aquarium in 1929 (Right) (Mortlock Library B19615 and B5473)
The building of a breakwater in front of the jetty was another of Light's dreams. There
were five attempts in total, however, all for them failed due to storm damaged (Jeans
1979, p.244). All of these were in the early 1900's, the last in 1917. Even though
environmental forces destroyed each attempt, only once was the designed changed to
allow for the destructive forces. The Public Works Officer, however, refused to allow
the changes as it would have meant a shorter breakwater, to compensate for the
increased costs for strengthening (GRG 23/97 [1917/20]). The contractors, Stone and
5
Siddeley, sued the government for the incorrect specifications of the jetty, and tried to
clear their name from the fault. The matter was settled four years later. All that
remains of the breakwater today are the foundations from the failed attempts, which can
be seen at low tide.
During this time there were two important additions to the jetty. The first was in 1907
when a pavilion room was built on the northern end of the jetty. The other addition was
not until 1929 when an aquarium was built. Placed on the northern side as well, it was
located approximately half way along the jetty. These two proved popular additions,
and soon became one of the focal points in Glenelg, and indeed South Australia.
Figure 6: The day after a storm destroyed the Holdfast Bay Jetty, 1948 (Mortlock Library B21596).
In 1928, the first of two severe storms struck that reshaped Glenelg. This storm
damaged and destroyed the Bathing jetty. By this time the Bathing Company, who had
control of the maintenance and operation of the structure, had gone into liquidation.
The upkeep cost of the baths was estimated to be around £1000 per annum, which the
council refused to pay (Jeans 1979, pp.192). The standards in bathing had changed and
there was no need for another bathing area.
A second and more ferocious storm was experienced April 11, 1948. In 24 hours,
everything was destroyed. The jetty and parts of the seawalls were demolished by a
6
series of strong winds and waves. All that was left standing of the Jetty was the
aquarium and the tearooms. The rest had been lost in the waves. Not even the 1,420
tonne Royal Australian Naval frigate The Barcoo could escape. It was in the area
surveying the Gulf and stationed at Holdfast Bay when the storm struck. The storm
carried the vessel from its anchors and beached it on a sandbar four and a half
kilometres north of Glenelg. The total damage of the storm was estimated to be
£250,000 (Jeans 1979, p.158-159).
It was not until May of 1969 that Glenelg saw another jetty. Built on the same spot as
the original, the present day structure is only 219 metres long and five metres wide.
Although considerably shorter then the original, the Holdfast Bay council was pleased
that the area had a Jetty again. Its use today is solely for recreational purposes, mainly
fishing and walkers.
At cost of close to $200,000, paid for by both the State
Government and the Holdfast Bay Council, the opening was on the 19th day of May
1969 (Jeans 1979, p.153).
Archaeology on the Holdfast Bay Jetty.
The Holdfast Bay Jetty was first excavated between 1974 and 1978 by the Society for
Underwater Historical Research (SUHR). The Society was founded early 1974 and all
members were in favour of taking on a project "of noteworthy interest and historical
significance" (Drew 1983, p.6). Like many new societies, early problems included a
lack of funds and equipment.
Lack of experience or qualification in maritime
archaeology also created difficulties. Their first project, excavating the Holdfast Bay
jetty, was used primarily as a training exercise so that future work conducted by the
society could be more efficient (Drew 1983, p.6).
7
The aims of the excavation were to find artefacts and pylons associated with the jetty.
The Society concentrated on the pavilion/tea room section located at the end of the
original jetty. This was chosen for its minimal interference with people and activities
on the existing jetty and also because it was already known that the area would be rich
in artefacts (Drew 1983, p.7). The area excavated in 1974 was marked out with four
star pickets. The excavation began with each diver being allocated a small section of
area to excavate by hand waving. The locations of the jetty pylons were important, as
they would indicate where the structure actually sat (Drew 1983, p.7).
An early
problem was that the first seasons material (up until 1975) had no provenance.
Figure 7: Excavation techniques used during the 1974-78 Holdfast Bay excavation.
(Photograph T. Drew)
When excavation continued in 1976, a photo-mosaic was taken of the marked out area.
The excavation continued by hand fanning, and divers were given a specific area with
the help of a base line running north to south between the outer two points. Divers
concentrated on a two-metre section at a time. When that area was finished, the divers
8
moved two metres south along the baseline. An area of thirty-eight metres long and five
metres wide was excavated in this fashion (Drew 1983, p.10).
The excavations
concluded in February 1978.
Artefacts were recorded in a book as they were raised, although some of the artefacts
were catalogued by SUHR members after the excavation. No analysis of this material
was conducted until 1983, where a publication of the project was written. In it, there
was a limited analysis of a few artefacts in the collection.
The material was re-
examined in 1999 by Jennifer Rodrigues as a part of an honours thesis in the
Department of Archaeology at Flinders University (Rodrigues 1999).
All of the
material was re-catalogued, giving new catalogue numbers. Where possible the original
numbers were also kept with the artefacts.
Figure 8: Map showing the location of the area excavated between 1974-78 (From Drew 1983, p.6).
Rodrigues' thesis was the only comprehensive analysis of the material completed, 20
years after the excavation. The material that was recovered in the 1974 to 1978
excavations was not used in this study for three reasons. Firstly, the objects do not have
9
provenance. Although the area excavated in 1974 was the pavilion/tea rooms, exactly
where the objects came from within this 20 metre by five metre trench is unknown.
There was also doubt divers kept to the marked out areas (Rodrigues 1999, p.12).
Secondly, the purpose of this investigation was to examine the material in relation to its
positioning within the deposit; which requires three-dimensional plotting. This level of
recording was not employed by the SUHR members during the 1974-78 excavations,
therefore making the material from this earlier excavation useless for the purpose of this
thesis.
Figure 9: An example of the method used to record where artefacts were found during the 1974-78
excavation. (Adapted by N. Richards),
The third reason why the 1974-78 material could not be included has to do with the
collection practices employed. Rodrigues stated that it was clear from the material
raised that divers were selecting the artefacts were recovered (Rodrigues 1999, p.174).
Only objects that were of particular value or were intact were collected. This selection
process means that the collection was not an accurate representation of what each of the
deposits contained.
Holdfast Bay 2000 Fieldwork and Methodology
It was decided by SUHR to re-excavate the Holdfast Bay Jetty in early 2000. The aims
of the project were to conduct a controlled excavation around the Jetty, which would
10
also serve to promote maritime archaeology in South Australia. While at the same time
reactivating the Society (Richards 2000, in press).
Rather than examining any one area, as occurred during the first excavation, it was
planned to investigate the five different activity areas associated with the original jetty,
as well as two control trenches. The five areas included the aquarium (Area C), main
berthing platform (Area E), underneath the actual jetty structure (Area F) and the
pavilion/tearooms (Area G) (Figure 10). The bathing structure, located 90 metres north
of the jetty, had also an area marked out (D). Two control trenches were placed near the
shore on the southern side of the jetty. These were to examine the possible movement
of artefacts in the direction of the prevailing current, which is south to north.
Figure 10: Ariel photography showing the site and location of the trenches that were excavated.
The areas were marked out in varying sizes according to the shape of the structure under
investigated. For example, the aquarium was a narrow and rectangular construction.
The area marked, therefore, was a four by eight metre trench, running in the same
direction as the aquarium. The bathing area was also marked out the same size. This
size was chosen in an attempt to find pylons associated with the structure. Areas E, F
and G were all 6 x 6 metre trenches. This square design was incorporated to get as
much information about that local area as possible, without overlapping adjacent
11
trenches or activity areas. The control trenches, areas A and B, were 2 x 2 metres and 2
x 4 metre trenches respectively.
All of these areas were segregated into smaller 2 x 2 metre sections. This was to help
with the recording of objects in three dimensions, and to specifically flag which
trenches artefacts had come from (Green 1990, p.125; Dean 1992, p.157).
Steel
reinforcing rods one metre long was used to mark the extent of each unit. They were
hammered in to a depth of at least forty centimetres to ensure that each stake had
entered the limestone substrate for greater stability.
Figure 11: An example of the labels used to identify each stake. (Photograph by K. Brown)
Each stake was given a number for easy identification while underwater (Green 1990,
pp.150-151). Fluorescent builders' plastic was placed over the top of each one. A letter
according to the area and a number were attached to the stake. For example, area E's
stakes were labelled "E 1", "E 2" and so on. Numbering started from the south-western
most stakes, and ran north up the side of the trench. At the end of that line of stakes,
numbering returned to the second-most southwesterly stake and continued north. In all
93 stakes were used to mark out 196 square metres (Richards 2000, unpublished
research design).
12
This pre-disturbance work commenced on 11 January 2000, taking until 30 January to
complete. During this time scale drawings of each individual areas was completed.
This was to record the seabed before it was disturbed (Dean 1992, p.164). After
recording all seabed debris was removed from within each trench.
Figure 12: Operating the head of the air dredge (Left) and recording in operation (Right)
(Photograph K. Brown).
The excavation began on 4 February 2000. This was in accordance with the dredging
permit issued by the Environmental Protection Agency (EPA). The format of each day
was to meet and leave Holdfast Shores in the morning. The boat carried six people,
including all the dive gear needed for the day. Once on the site, there were three dives
planned a day, a maximum of three people in the water during each dive.
Excavation was carried out with a water dredge (Green 1990, p.136; Dean 1992, p.211).
The pump was mounted on the inflatable raft, tied to the back of the main boat. This
was so that the noise from the pump did not interfere with the underwater
13
communications.
A two by two metre section was concentrated on at a time to
guarantee the relocation of the artefacts to that specific area.
Recording of all material was done in situ. Four measurements were taken from each of
the four corner posts. This was to provide three-dimensional measurements to help in
the analysis later on (See Methodology of thesis). Afterwards, the artefact was removed
and placed into a pre-labelled bag, which had a catalogue number on it. This was so the
measurements that were taken could later be matched to that specific artefact.
Due to time constraints, only two sections within each area were excavated. Area D
was not excavated at all during the fieldwork. The two sections in all areas were the
southwesterly most grid section and the one immediately north. In area F three trenches
were excavated instead of the two. The shallow deposit encountered in the first trench
of area F allowed for a third trench to be excavated. In all 12 of 49 units were
excavated. The excavation finished on 1 March, having incorporated 147 dives totaling
6,648 minutes underwater (Lewczak and Richards 2001, in press).
Cataloguing and Conservation
Cataloguing and conservation began during the excavation, the day that the artefact was
removed from the water. Two transportable rooms were donated by Heritage South
Australia and acted as the cataloguing and conservation labs, located at Netley. All
material was entered into a database established in Microsoft Access.
This had
previously been constructed by Nathan Richards and Jennifer Rodrigues for use in recataloguing material from the 1974-1978 excavation.
14
The main reason the database was used was to allow for the easy analysis of the
material. Specific analysis could be carried out for each activity area as well as on
individual objects. The database centred on recording as much information about each
artefact, its fabric, use, measurements and any other diagnostic markings. Appendix 1
contains an example of the all the fields contained in the database.
Figure 13: Conservation work being carried out by two of the many dedicated SUHR members.
Conservation began once the materials had left the water. Each artefact was placed into
a bag that could be easily sealed and filled with seawater. At the end of each day, the
artefacts raised were brought back to the transportable rooms for further conservation
work to begin.
All objects were kept in seawater until the next morning, when the water was changed.
Approximately half of the water was released and the bag refilled with tap water. The
artefacts were then left for two days. The water was then changed and refilled, keeping
each artefact in its own bag. This process ensured that artefacts could not be placed into
the wrong catalogue bags. The water was changed in each artefact bag at least once
every two days.
15
Full conservation was conducted by members from SUHR. Objects that require specific
or detailed conservation work were taken to ArtLab to be conserved. It was the aim of
SUHR to try to do as much conservation as possible themselves. This was to keep the
cost as low as possible, and to begin training members in conservation for future
projects.
Methodology.
The methods needed to investigate artefact movement in marine environments involved
the measuring of all artefacts in three dimensions. These measurements were taken in
accordance with the methods recommended in the Site Surveyor handbook. This was so
the measurements that were taken could easily be adapted into the Site Surveyor
software. The software can recreate any marine deposit as a three dimensional plot.
On site, the steel reinforcing rods used to mark out each trench from within each trench
were used as the controlled measuring points.
This was a very accurate way of
measuring the artefacts as the tapes could be attached to each stake and kept to the one
level during the excavation of that trench (Lewczak and Richards 2001, in press). For
use in the Site Surveyor software, each stake was measured to and from four other
stakes. This was to ensure an accurate shape and distance between all grids. All of this
information was then placed into the Site Surveyor software. The results of the Site
Surveyor can be seen in Chapter 5.
In investigating whether deposits are in chronological layers, coins were used in two
and three-dimensional plots. The dates from the coins were taken as the earliest date
that they could have entered the deposit, a large date range between two adjacent coins
16
was investigated in an attempt to discover if they were deposited as the dates indicated
or if there was environmental disturbance of the site. The clearest form of a nonchronological ordering in the coins would be the appearance of a modern metric coin at
the same depth as an imperial coin as these coins were never in circulation at the same
time. Any other diagnostic material was also be used to help support any conclusions.
Researching the possibilities of patterns occurring in a non-chronological deposit
required a more complex method. Individual artefact densities will be determined to
investigate a correlation between the density of the object and its position (Keller 1972;
Moeyersons and Cahen 1977).
The density of each artefact was determined mathematically using the formula:
Density = Volume
Weight
There are two ways to determine the volume of an object. The first is to measure the
amount of water that the object displaces. The other way is to use mathematical
formulas. Volume of an object can be determined by using:
(A) For rectangular pieces:
Volume = Length x Width x Height
(B) For a solid cylinder:
2
Volume = .r . Height
17
(C) To find the density of a hollow cylinder:
1. Determine the total density by using formula B.
2. Measure the radius of the hollow section and then use that number in the
same equation used in the first step.
3. Subtract the answer of step two from the answer of step one for to get the
answer.
(D) For a solid Sphere:
Volume = 4/3..r3
(E) For a hollow Sphere:
1. Determine the density for a solid sphere by using formula D.
2. Measure the radius of the section that is hollow
3. Import that figure into formula D
4. Subtract the answer of step one from step three to determine the answer.
The method employed was determined by the shape of the object and whether it could
be placed into a beaker to measure the amount of water displaced. Measuring objects in
water was used for irregularly shaped objects. There were two exceptions to this
method. The first were objects too small to measure the amount of water that they
displaced.
The other exception was with objects that were absent from the main
collection. These were objects had been separated from the collection in preparation for
a museum display.
For these the mathematical formulas were used based on
measurements recorded in the database.
The Site Surveyor data was used as a guide to the general layout of the trenches for
investigation of density patterning. Two-dimensional graphs were created with the
Excel software to show a simpler representation of the deposition of the objects and
their densities. Other specific analyses were carried out using the same graphical
18
representation; however, the other information was substituted for the density data, such
as material type.
The material analysed came from areas E, F, and G only as the majority of artefacts
came from these three trenches. They were also used as they were all in a parallel line,
the same distance away from shore and therefore experienced the same environmental
influences. The seabed depths in all of the trenches were similar, as were the depths of
the deposits. This made it possible for the three areas to be compared to each other.
Thesis Outline
The first chapter of this thesis relates to the practical and theoretical contributions of
artefact movement, and the affect that the environment has on archaeological sites
underwater.
This is immediately followed by the presentation of the fundamental
operations of coastal environments.
From understanding how a coastal sediment
deposit can be effected by the environment, a specific examination of the Holdfast Bay
environment allows us to coming to terms with how the natural environment has
affected the deposits.
Chapter three presents a brief analysis of the artefacts that were uncovered during the
excavation. Chapter four conducts the first investigation into the artefacts positions to
determine whether the deposits are arranged chronologically. Determining chronology
on the site was by examining the position of the coins found in areas E, F and G. In
addition to these coins, other diagnostic material was used to help aid any statement
made out the subject matter.
19
The following three chapters investigate the hypotheses proposed during past research
into artefact patterning, and tests them against the Holdfast Bay data. These three
investigations are aimed at the artefact’s density, material type and finally an
investigation into both of these attributes in relation to one specific artefact, coins.
Artefact densities were firstly examined to determine if density correlated with the
depth of the object within the deposit. In chapter six, the investigation substituted the
density of a given artefact with the material that it was made of.
Each of these
investigations was conducted separately.
The third investigation, discussed in chapter 7, examined the positioning of coins in
relation to each other. Coins were chosen as they were all made of the same material
and were all shaped identically.
This resulted in all of the coins having similar
densities. The positioning of like objects to one another would reveal whether they
formed a pattern. Keller believed that artefacts with like densities, material types and
shape would be located in similar position within the deposit, thereby forming a pattern
(Keller 1972, p. 189).
The thesis is then wrapped up with a discussion of all four investigation's results.
Future investigations and how this research could be furthered is discussed.
20
1. Literature Review
Examinations of how the environment can effect an underwater site have been limited
in maritime archaeology (Keller 1972, Murphy 1990). There has been, however, an
increased interest in recent times. The latest article in Australia was written by Ward,
Larcombe and Veth (1998). All of these studies, including the last, draw upon a wide
range of disciplines to try to understand environmental effects on shipwreck sites.
Nevertheless, those investigated from a maritime archaeological point of view have
generally kept to three aspects. Firstly, they are either looking at the environment in
terms of preservation of a site (Strachan 1988, Hosty 1988, Guthrie et al, 1994, Koskikarell 1994, Moran 1997, Bratten, 1998, Waddel, 1999); secondly, they look only at the
horizontal spread of artefacts. The third and the most important point is that the
majority are concentrated on shipwrecks.
There are few underwater archaeological studies into non-chronological deposits (Keller
1972; Murphy 1990).
They have proposed a number of theories related to the
movement of artefacts in marine deposits. These theories have rarely been taken further
than the hypothesising stage. The reason may perhaps be due to a lack of interest in the
investigations and/or limited time that is available during larger projects (Keller 1972,
p.189).
The studies that have examined influences over a shipwreck site have highlighted some
of the potential environmental factors that effect other marine deposits as well. Some of
the findings indicate that there is a possibility that the environment constantly disturbs
21
seabed deposits. It is the aim of this section to present the processes and theories that
will ultimately be applied to the Holdfast Bay material.
Case Studies
Most of the theories that are of particular interest to this investigation come from
projects that have highlighted the environment and how it can affect an archaeological
site; especially those that have documented direct environment influence on the site, or
specifically cause mixing in a deposit.
The first insight into non-chronological ordering in deposits comes from research
conducted by the Norwegian Museum in the early 1970s. One of the few maritime sites
not to be connected on a shipwreck, they began investigating stratigraphy in Norwegian
Harbours.
The aim of the project was to see if archaeological deposits in small
sheltered harbours around the Norwegian coastline were arranged in chronological
order.
The project looked for typical waste from ships that was also diagnostic,
primarily bottles, pottery and clay pipes. It was held that the datable material would
give some indications as to when the sheltered bays might have been used (Keller 1973,
p.187).
The first bay investigated, Mandal Bay, was chosen as a result of reports from sports
divers who claimed to see scatters of artefacts appearing and then disappearing on the
seabed (Figure 1.1). The bay is composed of deep silty sediment and mud. The
excavation revealed that there was no chronological ordering in the deposit. This was
strongly confirmed by the presence of a 20th century Coca-Cola bottle lying under an
assemblage of clay pipes (Keller 1973, p.187). Suggestions were made as to why
22
artefacts were not appearing in chronological order. These included the movement of
material caused by propeller wash and constant wave action (Keller 1972, p.188).
Movik
Mandal
Figure 1.1: Location of Mandal and Movik Harbour, Norway (Source Encarta 1998).
A geologist participating in the project later noted that artefacts could move through
sediments. When the specific gravity of an artefact is higher than the underlying
sediment it could enable the artefact to sink through the sediment (Keller 1973, p.187).
This sinking could continue until the gravity of the sediment equalises with the gravity
of the object. This type of movement is more susceptible in unconsolidated sediments
due to the sediments low density. The constant movement of water over the sediments
does not permit stable sediment morphology (Keller 1973, p.187).
The Norwegian Museum held a second excavation at Movik Harbour in 1971 to
confirm the findings (Figure 1.1). During this excavation, chronological stratification
was clearly seen, the opposite of that found in Mandal Bay. The densities of the
artefacts were recorded in an attempt to reveal any correlation between the position of
the artefact and its specific gravity. As the deposit was already in a chronological
sequence a density patterning was not seen in the deposit. Artefacts of high densities
23
were found with objects of low densities. Some exceptions were noted, particularly
with lead objects (Keller 1973, p.188). The project was never finished, as Keller and
the Norwegian Museum recognising that further sites needed to be investigated from
other areas around the world.
Figure 1.2: Location of Kinshasa, Democratic Republic of Congo (Source Encarta 1998).
J. Moeyersons and D. Cahen (1977) investigated the possible movement of stone
artefacts within terrestrial deposits. The excavation at Kinshasa, located in the Congo
River Basin, Democratic Republic of Congo (formally Zaire), uncovered some
interesting observations. During the excavation, stone cores from the deposit were
found as well as a number of flakes. It was discovered that the flakes could be
conjoined with the cores (Moeyersons & Cahen 1977, p.812). The conjoining flakes
were distributed irregularly throughout the deposits at all depths.
Also dating of
charcoal remains from the different layers near where these stone artefacts came from
were reported to have a date difference of hundreds of years between them.
Moeyersons and Cahen started to conduct experiments to see if it was possible for
artefacts to move vertically through the deposit.
24
The environment was recreated, including simulating the seasonal weather conditions of
the area. The outcomes showed that artefacts could penetrate down through the soil
during a single year (Moeyersons & Cahen 1977, p.815). Although it is not the same as
a marine environment, it demonstrates that artefacts can move. It should also be noted
that it was through the times of rain and/or flooding that the sorting occurred. Dry
periods allowed the sediment to consolidate, thereby blocking the passage of artefacts
vertically.
This confirms the Norwegian harbour findings that suggested vertical
movement of objects occurred when the sediment was unconsolidated.
Most of the cases have been mentioned have looked at the possibilities of downward
movement in the stratigraphy. Stockton, in 1973, excavated a shelter in New South
Wales where pressure over the site, mainly caused by trampling, was seen to move
objects to the surface as well as push them downwards (Stockton 1973, p.116). In
testing his theory, fragments of red glass were thrown onto the ground where it was
covered by five centimetres of soil. People were encouraged to walk over the site
through the course of a single day.
The next day the section was excavated in
controlled levels. Some of the red glass penetrated sixteen centimetres into the ground,
while other pieces were pushed upward into the top five centimetres of soil placed on
top (Stockton 1973, p.116).
The upward movement was explained by the orientation of the glass fragments at the
time that pressure was placed on them. A large flat object may sink into the sediment
slightly, but if the pressure is placed to one side, then it could tilt the object upward
(Matthews 1965 in Stockton 1973, pp.116-117).
25
The most recent examination of vertical artefact movement in the marine environment
comes from a report by Murphy (1990) for the Submerged Cultural Resources Unit in
the USA. This report investigated the possibility of vertical movement of prehistoric
material through the stratigraphic layers off Douglas Beach, Florida. The deposit was
uncovered in 1964 when a commercial historic shipwreck salvage company began
salvaging a 1715 Spanish shipwreck (Murphy 1990, pp.2-3). At the time of the initial
salvaging, stone artefacts were raised with some of the shipwreck material. Considered
not a part of the vessel that was being salvaged, the crew discarded much of it. In 1976
another salvage operation was held on the same Spanish wreck. This time they were
accompanied by field archaeology agents to collect all faunal and prehistoric remains
(Murphy 1990, p.7).
The material uncovered was sufficient to warrant a further investigation into the
prehistoric remains that were underneath the shipwreck. The focus of the investigation
was to locate and examine the artefacts and their environment. Particular attention was
placed on the environment as there was little understanding about the natural site
formation processes and how they might have effected a saturated site (Murphy 1990,
p.4). Prop-wash, the method of directing the output from a single screw engine onto the
seabed, was used to excavate through the different layers. This was used because there
was a large amount of sterile sediment above the deposit. The technique enabled 932
holes to be excavated with the use of two vessels in 46 days (Murphy 1990, p.7). The
archaeologists involved recognised the limitations of using prop-wash, in that it is hard
to control, and difficult to record artefacts without disturbing them.
26
During the excavation, 11 artefacts and over 100 faunal fragments were uncovered. All
of the artefacts were located in one stratigraphic layer, while the faunal remains were
from a mixture of layers underneath the shipwreck. Two of the artefacts were ceramic
fragments that were not consistent with the other material uncovered (Murphy 1990,
pp.32-35). There is, unfortunately, only horizontal data available for the position of the
artefacts. The artefacts, however, were generally noted to have come from the middle
sections of the stratigraphy (Murphy 1990, p.35). Core samples as well as sediment
samples were taken during the excavation to assess the stratigraphy on the site. There
were a number of clearly defined stratigraphic layers in the deposits, indicating a
relatively consistent build up of sediments in the area, rather than a turbulent
environment.
From the analysis of the environmental impacts on the geological and archaeological
deposits, the conclusion was made that the environment, specifically waves, had a
minimal impact on both deposits. Wave motion over the site would not have a great
effect on the sediment. Due to the depth of water over the site, only the top layers of the
sediment deposit were considered to be effected (Murphy 1990, p.52). Sea levels were
also looked at over the course of the last 14,000 B.P. This was to accommodate the
period before the sea level rose above the level of the excavated area. The constant rise
in sea levels has limited the wave exposure of the site (Murphy 1990, p.52).
The limitations of environmental influences over the site implied that the artefacts have
been protected.
Artefacts from the Spanish shipwreck were found with sediment
abrasion on them (Murphy 1990, p.52). As they were present on the site after the
27
prehistoric material, it seems that they sat in the areas of the deposits that were affected
by the environment, offering another layer of protection to the prehistoric material.
The question of artefact movement discussed by Murphy was not possible to calculate.
This was primarily because of the excavation methods employed. The prop-wash
technique had no control on the amount of sediment that was removed nor the care
taken in removing them, dislodging the artefacts at the same time as removing the
sediment (Murphy 1990, p.52). Murphy did, however, suggest that artefact movement
was reliant on how far down waves could penetrate. Artefacts that had artefact densities
higher then the sediment around them would move until they were deep enough into the
deposit to be protected from the wave base, thus becoming stable (Murphy 1990, p.53).
Other theory and practical work
Environmental archaeology is a stream of archaeology that has been around for a
number of years. While it is looking at the environment, it is directed at:
… understanding the dynamic relationship between humans and the
ecological systems in which they live. … Environmental archaeologists
apply information and techniques from the natural sciences to studies of the
human past through the analysis of archaeological deposits.
(Reitz 1996, p.3)
From the definition quoted above, environmental archaeology looks at the human
interaction with the environment and their adaptation to it.
There are some
28
investigations by environmental archaeologists that have looked at the effect of the
environment on deposits. These, however, have been limited in their scope.
One paper entitled "Geoarchaeology and Archaeostratigraphy" by Julie Stein (1996)
looked at chemical patterning in the stratigraphy of a shell midden. Although it looks at
the effect rain had in pushing fragments of carbonate into the lower levels of the
deposit, the focus was on the chemical influence that this caused in the soil (Stein 1996,
p.51).
Work on formation processes and artefact collections are generally associated with
human activities and behaviours. Much of the work has concentrated on the objects in
terms of use, trade, and discard, while sites have been looked at in terms of the way that
they are set out (landscape archaeology). These distribution studies are directed more at
the horizontal distribution of sites. The aim of this thesis is to investigate vertical
movement, rather than horizontal movement of artefacts after deposition.
Both Binford (Binford, 1962, 1964, 1965, 1978) and Schiffer (Schiffer 1972, 1975,
1983) examined artefacts and deposits from the view of understanding the people
behind them.
Binford investigated more at the activities and the refuse that they
created, while Schiffer's study was more towards the behavioural patterns in the lay out
of sites. It is not the intent of this thesis to analyse the artefacts to see what they tell us
about the people who went on the jetty. Instead it is directed at the taphonomic factors
occurring on the site.
29
The writings on artefact patterning in the archaeological record are connected with the
study of two similar sites and comparing the artefacts to see if there is a patterning
within the objects found (South 1977, p.84).
For example, they are looking for
predictable what artefacts may be present in sites that are of similar nature. An example
of this type of artefact patterning would be the prediction of the artefact assemblages on
a 19th century butcher shop site based on previous investigations on similar sites from
the same time period. In this thesis, the artefact patterning was not based on the
artefacts themselves, as such, but their position in the deposit. The difference in the use
of artefact patterning is what separates these studies. The important elements being
selected here are their weight and size, rather than what the artefact is.
Schiffer's "n-transformation", or non-cultural formation processes, concerns itself with
all effects on a site caused by the environment, that is, through animal, physical or
chemical interactions. These interactions can be attributed to instability in a deposit or
over a whole site. The outcome stated by Schiffer is the same that this thesis wishes to
achieve with the Holdfast Bay material, that is, to understand some of the interactions
between the environment and cultural material (Schiffer 1976, p.4). Keith Muckelroy
did a similar investigation, specifically looking at the marine environment and the
shipwrecking process.
Muckelroy's investigation on the wreck of the VOC ship Kennemerland (1664) (Price &
Muckelroy 1974; Price & Muckelroy 1977) began to look at scattered sites, those that
had no real coherent structure (Muckelroy 1975, p.173), and sites that have obviously
had some type of destructive force acting on them. The Kennemerland site was the start
of attempting to understand the environment in relation to maritime archaeology.
30
Figure 1.3: The ship wrecking process according to Muckelroy (Muckelroy 1978, p.157)
Further work on Kennemerland produced a flow diagram showing the process of
wrecking (Muckelroy 1976, p.282). In this guide for understanding the development of
a shipwreck, the environment was taken into account (Figure 1.3) (Muckelroy 1978,
p.157). This environmental consideration, however, only included the movement of
sediment across the site.
It was not until 1977 that Muckelroy went further and looked at the environments of
twenty shipwreck sites from around Britain. Wanting to see if there were correlations
between the environment and the condition of sites, he produced eleven attributes that
affected the site in varying degrees. These were:
31
1. Maximum offshore fetch, within 30 degrees perpendicular to the
coast.
2. Where there are more than 10kms of open water over the site.
3. Amount of time that there are force 7 winds on the site
4. Maximum speed of tidal streams across the site
5. Minimum depth of the site
6. Maximum depth on the site
7. Depth of deposit on the site
8. Average slope of the seabed
9. How much of the site has sediment movement over it
10. Nature of the coarsest sediment (transitory or stationary)
11. Nature of the finer material
(Muckelroy 1977, p.50)
It is clear that the majority of these attributes involve the movement of water. The
preservation or deterioration of each site could be determined by how the above
attributes acted on the site.
The reasons for the investigation were to understand the preservation of sites and the
artefacts associated with them (Muckelroy 1977, p.55). This was to aid his research
into understanding the wrecking processes. His research led him to believe that the
natural forces affecting the site were only effective during the wrecking stage. He
concluded that; "…once initial deposition has been made, these forces have little effect
on the subsequent fate of a site" (Muckelroy 1977, p.52).
All of Muckelroy's conclusions were edited and revised in his 1978 book Maritime
Archaeology. His work, starting in 1975 on the Kennemerland and finishing with this
32
book, centred on the preservation of each site. The effect that the environment had was
suggested again as being only influential during the time of wrecking. He mentioned
that attributes 1-7 of the 11 stated above did not affect the site after deposition
(Muckelroy 1978, p.52).
From his research, Muckelroy also questioned Keller's work on Norwegian Harbours.
He believed that sediments are, in fact, formed in chronological order, suggesting that
artefact movement in the stratigraphy is "overemphasised" (Muckelroy 1978, p.176).
According to Muckelroy, vertical movement can be accounted for by the layer of
sediment that is highly transitory (unconsolidated) above the stable (consolidated)
sediment. Also, the transitory sediment, can at times, cover or move artefacts while the
heavier ones are more stable. The movement causes the artefacts to accumulate before
being redeposited (Muckelroy 1978, p.176).
Later Schiffer added two essential aspects about the formation of deposits that
Muckelroy did not include. Although it was looking at the horizontal spread, Schiffer
included the issues of perturbation, later focusing on faunal-turbation (Schiffer 1987,
pp.143-145). This work was conducted by Wood and Johnson (1981) who looked at all
the possibilities for disturbance in an archaeological deposit. One other influence they
included that is of particular interest for archaeological remains in marine environments,
is floral-turbation (Wood and Johnson 1981, p.542).
Ferrari and Adams (1990) have analysed the effects that burrowing marine animals had
on shipwreck sites. Looking not only at wood-boring animals, the authors took into
consideration those animals that burrow underneath objects or structures that offered
33
them protection from the environment and predators (Ferrari & Adams 1990, p.142145). Another study concentrated on the presence and absence of sea grasses in the
marine environment (King 1981, p.207). Seagrasses offer the same protection needed
by burrowing animals, but also affect the matrix of the seabed. These will be discussed
with other natural influences in Chapter 2.
Keighley (1998) examined the wreck formation proposed by Muckelroy, and expanded
on this formation process theory by adding more environmental factors. The aim of this
thesis was to investigate whether a cross (multi) discipline approach would increase our
understanding of the factors involved in the formation process. A key point highlighted
in Keighley's work is the variety of environmental influences. One in particular was to
do with the seabed, largely its composition (Keighley 1998, p.13).
The many environmental factors to consider were compounded when the amount of
water over the site was included in relation to the different seabed types. On top of this,
there are the many variable to consider when taking into account the nature of the event
that cased the sinking, either on purpose, disaster at sea of hitting/ground with land
(Keighley 1998, pp 17-26). Keighley concluded that the nature of the environment in
relation to the wrecking process is so complex that it is not something that can be
generalised (Keighley 1998, p.82). This is exhibited in his thesis by presenting the
many classifications that have been written for shipwrecks in the different European
areas, such as the Baltic, Mediterranean and for one in British waters.
In the latest paper presented into environmental effects in maritime archaeology, Ward,
Larcombe and Veth (1999) reshaped Muckelroy's flow diagram of a wreck process to
34
include more predictive measurements. The authors believed that the existing formation
processes fail to "…distinguish between process related and product related attributes
and consequently are more descriptive then predictive" (Ward et al 1999, p.561). Their
reasoning for this was that the environment effects each archaeological site and deposit
differently. The models, therefore, can only predict small circumstances of the wreck
formation processes.
Figure 1.4: Edited version of Muckelroy's Shipwrecking Process by Ward et al (After Ward et al
1999).
Ward, Larcombe and Veth also introduced measurable parameters on sites that can help
determine preservation and the coherent nature of a site. What they propose to include
are influences such as sediment budget and hydrodynamic environment, or water force
over each site (Ward et al 1998, p.1; Ward et al 1999, p.562) (Figure 1.4). These two
attributes are interrelated in their actions, as the sediment budget, the amount of
sediment deposited in a given position, either accumulates or erode according to the
amount of force exerted by water movement. The stronger the current and/or the bigger
the waves on a site, the more erosion that will occur.
35
Ward et al stated that the amount of water or sediment movement over a site can
influence a site, both physically, biologically and chemically (Ward et al 1999, p.565).
The most important to the Holdfast Bay study, which will also be expanded upon here
and in the discussion are the physical characteristics.
Sediment accumulation can protect the site from deterioration caused by chemical
reactions or from periods of higher water action, such as storm events. However, if the
site was in an area where the level of hydrodynamic activity was high, then a site could
be blown apart and material distributed off site. Whichever element is present on the
site will determine the future of the site. Once sediment has covered the site, or objects
have settled into it, the sediment will protect the remaining parts of the wreck (or other
archaeological site) from further deterioration (Riley 1987, in Ward et al, 1999, p.566).
The potential of the Ward et al's altered model, which includes the sediment budget, an
understanding of the hydrodynamic environment, and chemical/biological deterioration,
was to gauge the location of wreck material in sediments at particular distances from the
wreck site (Figure 1.4) (Ward et al 1999, p.568). This could be taken further to include
material from other sites, such as jetties and to gauge the environmental impact on an
archaeological deposit.
There have been few investigations within Australia that have looked at archaeological
deposits in and around jetties. There have been two other excavations, excluding the
1974-1974 Holdfast Bay excavation, and many heritage surveys. Both excavations
36
were of jetties in Western Australia, excavated by Dena Garratt and the Western
Australian Maritime Museum.
The first jetty excavated was the Long Jetty, Fremantle, Western Australia. Long Jetty,
also known as the Ocean Jetty, was built in 1873 and was added to many times. From
the 1870s to the 1920s, the jetty was the focal point of maritime activities in Western
Australia. It effectively became the centre of trade and communications for the whole
state (Garratt 1994e, p. 1). Before the jetty was built, large ships needed the help of
smaller vessels to run to and from ship to load and unload their cargo.
Development of the harbour for the America's Cup saw the structure in line for
demolition. Funding was granted to the Western Australian Maritime Museum to learn
from the site before it was destroyed (Garratt 1994e, p.11). Although divers had
salvaged the area for many years, material was still believed to be present beneath the
seabed. Since the jetty was to be torn down, the objectives of the study were to map and
document the remaining structures, gauge the spread of material, raise and conserve
material and to assess the significance of the jetty (Garratt 1994e, p.11).
The excavation included the recording of all material remains in the study area. The
method used to excavate was prop-wash. A boat engine was powered to 1,000 rpm and
then released. The sediment removed totalled an area of 5 metres wide, 1 metre long
and 1.5 metres deep (Garratt 1994e, pp. 12). This could only be done in less than 5m of
water, and allowed for a large amount of sediment to be removed at once. Unfortunately
recording where the artefact came from in the vertical stratigraphy was impossible.
37
In total 1,143 artefacts were raised. The objects were classified by their material
composition with a brief description (eg coins, clay pipes, lead sinkers) (Garratt 1994e,
pp. 19-20). The material has yet to be fully interpreted and published.
The second jetty excavated was the Albany Bay Jetty, again in Western Australia. The
jetty was built in 1862 due to increased immigration to Australia after the Crimean War.
The structure was added to many times up until 1898 when the jetty was extended into
deep enough waters to allow most tonnages of vessels to dock (Garratt 1994d, pp. 6).
The jetty served its life out until the 1970s when there was no more need for ships to
stop at the Bay. In 1988, plans were made to redevelop the foreshore. This placed the
remains of the jetty in danger of being demolished.
In 1994, the Western Australian Maritime Museum was given funding to carry out an
archaeological excavation of the seabed around the remains of the jetty (Garratt 1995a,
pp. 19). The objectives of the excavation were to:
1.
Survey the areas under threat from the development,
2.
Define horizontal and vertical spread of artefacts,
3.
Analyse evidence to suggest strategies for the minimal impact from
development,
4.
Conserve material raised for collection/exhibition,
5.
Conservation strategies for the historic site.
(Garratt 1995a, pp. 19)
Many material deposits were located during the excavation. Most of the artefacts that
were uncovered related to the working life of the jetty. The material included ceramics,
glassware and locally made and imported bottles, many associated with vessels that
38
frequented the port. Also uncovered were mooring assemblages, namely mooring lines,
blocks and anchors (Garratt 1995a, pp. 42).
The excavation enabled analysis of the location of the artefact clusters in relation to the
activities on the jetty. It was revealed that artefacts were found in concentrations within
10 metres of the jetty itself.
However, around the docking area the artefact
concentrations were between 10 and 20 metres. This distance represents the width of
the vessels that docked in these areas. As the vessels were so wide, there was a sterile
patch with no artefacts between the jetty and the outer side of the vessel. This was seen
to affect the overall spread of objects (Garratt 1995, pp. 42).
The study of this jetty site helped confirm the findings from the Long Jetty excavation.
Although the excavation was meant to examine both the horizontal and vertical
distribution of cultural material, the former rather then the later was concentrated on.
This may have been due to the limited time and the pressure placed on the site by the
future development of the foreshore.
As mentioned earlier, there have been a series of 'Maritime Heritage Site Inspections
Reports of Jetties' produced by the Western Australian Maritime Museum. Numerous
jetties were inspected for their historic, technical, scientific, educational, recreational,
cultural and archaeological significance. A sample of these jetties includes the Hamelin
Bay Jetty (Garratt 1993), Eucla Jetty (Garratt 1994a), Israelite Bay Jetty (Garratt 1994b)
and Esperance Town Jetty (Garratt 1994c). As these Jetties were only physically
inspected, there was not a great deal of emphasis placed on what types of material or the
position of the artefacts in relation to the jetty.
39
All of the reports analyse the importance of the jetties in their historical context and
only mentioned that there was potential for further archaeological investigations. For
this reason, they have limited significance in this study.
Discussion:
The work conducted by the Norwegian Museum into the stratigraphic layering in
harbours highlighted the possibility that sediment deposits are constantly disturbed.
The investigation into Mandal Bay showed how deposits are susceptible to activities
that disorder them, such as waves, currents and even wash from boat propellers.
Although the further work in Movik Harbour indicated that there was stratigraphic
ordering of artefacts within deposit, it also indicated how the environmental influences
can vary in different areas; causing one harbour to have stratigraphic deposits, while the
other did not.
The eleven environmental and human attributes that Muckelroy proposed showed the
difference between a preserved or a scattered shipwreck could also explain the two
different results found by the Norwegian Museum. Although the eleven attributes were
created to provide an understanding about the shipwreck process, the same factors could
also be used to explain how different environmental attributes could affect the
placement of artefacts after the initial wrecking processes had concluded.
For example, the exposure of a site in an open bay is susceptible to strong tidal and
wind influences that stir up the seabed, affecting the deposit. The seven attributes that
40
Muckelroy believed did not affect a site after deposition are in fact the same factors that
seem to have the most potential in affecting a site located in a coastal zone. The
presence or absence, as well as the strength of any these seven attributes, or from the
other four that make up Muckelroy's 11 attributes, may be the controlling factors in the
amount of disturbance to the seabed that occurs.
Due to the effect that water movement can have on sediment, Keller believed that
sorting of the artefacts could occurred, according to the weight and size of the artefact
(Keller 1972, p.189). This was one of Keller's early hypotheses, but Moeyersons and
Cahen highlighted it again in 1977. Findings from their experimental research indicated
that during the wet season soils became unconsolidated, and artefacts were recorded to
have moved.
The weight and size of the objects that they used were taken into
consideration to determine is any relationship existed between its dimensions and how
much it moved; however, no conclusions were made.
The experiment that Stockton conducted in 1973 at Shaw Springs shelter excavation
uncovered a similar finding. The red glass that was buried was able to penetrate sixteen
centimetres through the soil after one day of trampling. Although there was no mention
whether the soil was unconsolidated or not, it seems likely that it was, and was a major
factor in the results.
Although these last two cases were not in a marine environment, the studies indicated
the effects of water and unconsolidated sediment on a site, and how quickly artefacts
can move down through the sediment.
A point that both the authors of the
investigations made, and one that this investigation wishes to take further.
41
Murphy's (1990) investigation into the prehistoric site found underneath a Spanish 17th
Century shipwreck of the coast of Florida is an example of the opposite to those that
have been presented thus far, a passive environment that has lead to stratification within
the deposits. Core samples that were take from the area showed that there were clearly
defined levels of stratigraphy of the sediment types. Although artefacts were recorded
to have all come from the same level, the stratification suggests that the site has always,
in terms of environmental influences, been low impact. Although there were clear lines
of stratigraphy, this site could be used to show how the absents of some of Muckelroy's
11 attributes can bring these clear stratigraphic layers to a site.
The opportunity that presented itself to excavate the area to re-enforce this point was not
taken. With the situation of a known 1715 Spanish shipwreck on top of a prehistoric
deposit, a systematic excavation could have detected whether objects from the
shipwreck were moving down towards the prehistoric material or not. It has to be
mentioned that the large amount of sediment between the seabed and the prehistoric
material would have taken a long time to remove without employing the prop-wash
technique. Murphy noted that only approximate horizontal positions could be recorded
for any material.
The results from the project did highlight one contributing factor to artefact movement.
Areas where the wave motion can influence the seabed will affect the distribution of
artefacts. Murphy suggested that objects with higher densities than the surrounding
sediment can move down into the deposits until they are deep enough not to be
influenced by the wave (Murphy 1990, p.53). This implies that artefacts can move
42
through sections of sediments that are affected by the wave action. It is inferred that
this wave action unconsolidated the sediment, which allows the artefacts to move. This
will be discussed further in chapters 2 and 3. Both Keller and Moeyersons & Cahen
(1977) made a similar suggestion in their research.
Murphy's results did factor in one important contribution to the theory of artefact
movement. His wave base theory, where artefacts are able to move until they are deep
enough into the deposit to escape the influence of the base of the wave, is another factor
to take into consideration. The artefacts that were observed from the Spanish shipwreck
were in the top levels of the deposits, where the base of the wave motion could affect it.
This is not to take anything away from the archaeological work that was done,
nevertheless, the chance to excavate the area in a more controlled manner would have
produced a more thorough investigation into artefact movement. In particular, how
wave motion may have affected the deposit and whether there was an ordering of the
artefacts.
As it can be seen, little has been done to identify whether artefact movement occurs in
different environments, and what influences there are acting on the site. By taking the
previous research and applying it to the Holdfast Bay site there is the potential to restart the investigations again from the controlled excavation that was held in early 2000.
The latest work on the environment by Ward, Larcombe and Veth (1998, 1999)
introduced formulas and relationships that can help determine sedimentation rates over
the site over long periods. If the environment in the area is known, then the measurable
43
parameters that they have included into Muckelroy's wrecking process flow diagram can
give some idea about the deposits. More specifically, they could be used with the
eleven previously mentioned attributes to gauge whether conditions are in favour of
object movement or not.
Other work conducted on the presence or absence of certain aspects of the marine
environment, with an archaeological focus or not, could help explain or predict how a
deposit may be effected by either burrowing animals, or the growth of sea grasses (King
1981, p.201; Ferrari & Adams 1990, p.139).
The work done on jetties in Western Australia, particularly from Long Jetty and Albany
Bay Jetty, brought many insights into how the Holdfast Bay Project was investigated.
The techniques used in the Long Jetty excavation did not allow for any type of plotting
of where the materials came from within the deposit. Although the use of prop-wash
was effective in removing a large amount of sediment, there is no real control of how
much sediment is removed at one time.
The excavation of the Albany Bay Jetty did offer some input into site formation
processes. The pattern of artefacts located 10 to 20 metres away from the jetty around
the berthing areas was a pattern that could be examined in relation to the Holdfast Bay
jetty. The aim of this thesis, however, was to investigate vertical movement of artefacts
and not horizontal movement away from the jetty itself. As the emphasis of the two
Western Australian jetties was on the horizontal placement of artefacts, they could not
be included in this investigation.
44
By using the controlling parameters set by Ward, Larcombe and Veth, the amount of
sediment and wave energy can be gauged to specify what type of environment Holdfast
Bay has in relation to others. Also by adding to it Muckelroy's eleven attributes, and the
information from the other studies, these will help further explain the specific
environment that Holdfast Bay has. Ultimately this could be used as a starting point and
a reference for further work in understanding the environmental influences onto
archaeological deposits in coastal zones.
All of these theories can be tested on the Holdfast Bay site as the deposit sits in
unconsolidated coastal sediment. This can be taken further to suggest whether the
constant influence of water continues to disturb the site by either enhancing the sorting
of objects by their weight and/or size or continues to jumble them up.
45
2. Environmental forces acting in coastal zones and in the Holdfast
Bay environment.
Environmental forces.
One of the important considerations of this thesis involves the coastal environment; in
particular, how environmental forces can influence an archaeological site. As already
mentioned in chapter 1, there have been few such studies focusing on underwater sites.
Muckelroy's formulation of the 11 environment attributes that he considered important
during the time of a ship wrecking is perhaps the best example (Muckelroy 1978,
p.150).
There have been many studies made into understand the complex coastal zone
morphology (Kinsman 1965, Komar 1983b, Johnson 1977, Massell 1989, Hordisty
1990). To understand how an archaeological deposit can be disturbed, it is necessary to
understand the processes that affect the coastal zone. Specifically the factors that cause
or interrupt sediment transportation.
The following chapter will summarise the
environmental processes that occur in a general near-shore coastal zone. An assessment
will then be made to determine whether these processes are at work in the Holdfast Bay
site is possible.
The areas that were excavated during the Holdfast Bay project ranged from close to
shore to three hundred metres out from shore. The material that will be analysed in this
thesis came from three trenches that were excavated in the section of the coastal zone
referred to as the near-shore zone. This zone in the section of the coast that begins in
46
the mid-surf zone and runs away from the shore towards the end of the coastal area
(Leeder 1982, p.198) (Figure 2.1).
Figure 2.1: Location of the different coastal zone areas. (Adapted from Davis 1985, p.386).
Beaches are defined as the zone of unconsolidated sediment that extends from the
uppermost part of wave action to the low water mark (Davis 1985, p.379). As the sand
is unconsolidated, it means that it is moved freely and distributed to other sections of the
beach. Unconsolidation of sediment on the seabed is directly associated with the same
forces involved in sediment transportation along the beach (Fredsoe and Deigaard 1992,
p.83).
There are four principal physical forces active in the coastal zone. These are tides,
wind, waves and currents (Gross 1977, p.305). These four forces modify coastlines and
seabed characteristics. Some are stronger than others, however, when there are groups
of these factors working at the same time, they have a much stronger impact (Leeder
1982, p.196). Each of these four will be examined as to how they work on the coastal
zone. This will be immediately followed up by a discussion of the specific environment
of Holdfast Bay.
47
Wind
There are two types of winds that effect near-shore morphology, direct and indirect
winds (Davis 1985, p.407).
Firstly, indirect winds are those that generate waves
offshore that will eventually reach the coastal area. The longer that the wind blows in
one direction, the greater the energy that is transmitted to the wave. The distance that
the wind can blow uninterrupted over the water from one direction (Komar 1983a, p.1)
also affects the wave. The longer the distance that the wind blows over the water the
stronger the waves that can be generated. This will continue until the wave is interfered
with by entering shallow water or until the wind ceases.
The second type of wind blows directly onto the shore. These winds are similar to the
indirect winds. The difference is that they have more of an influence on the beach and
sand dune zones (Bird 1984, p.176). These winds also generate waves that will end up
on the shore. Being a direct wind, the waves begin closer to shore, resulting in a shorter
run into the coastal zone. This will have an influence on the total energy that is
transmitted onto the beach (Davis 1985, p.408).
Winds created during storm events alter wave angles and strengths. These winds are
stronger than winds usually experienced in the area (Davis 1985, p.409). These winds
then have an influence on the waves and their angle to shore. As they create stronger
waves and change their angle to shore, they attack the seabed and beach from a slightly
different approach (Gross 1977, p.225). Although this is a short-term affair, storms can
dramatically rearrange sediment deposits.
48
Winds that are experienced over Holdfast Bay are recorded at Adelaide Airport. The
airport is situated 8kms south of Adelaide and only 4kms north of Glenelg (Figure 10).
This data has been collected since 1961 and has been produced in the form of a wind
rose,
put
together
by
the
Bureau
of
Meteorology
(www.bom.gov.au/weather/sa/forcasts.shtml). Wind readings are taken twice a day, at
9 a.m. and 3 p.m. The varying wind types experienced in both the mornings and
afternoons will be discussed.
Winds during the spring and summer months (September to February) are similar in
their direction and strength. The strongest winds in both seasons come from the south
and west. Most notably is the dominant southwesterly wind that blows straight up into
the gulf towards Adelaide and Holdfast Bay (Figure 2.2).
During the morning there is no one dominant wind direction. The winds come from all
directions, both as onshore and the offshore breezes, where as winds observed in the
afternoons predominantly come from offshore directions (Figure 2.2). There are times
when there are strong winds blowing from over the gulf waters across to Adelaide and
Holdfast Bay; however, these are for a shorter period of time (Figure 2.2).
During the autumn months (March to May), winds are more likely to come from the
north and northeast (Figure 2.3).
The mornings are generally the calmer period,
indicated by the larger sized circle in the centre of the wind roses in figure 2.3. Wind
gusts from the west continue to bluster in the afternoons during this period. The
strongest winds again come from south, southwest and westerly directions (Figure 2.3).
49
Figure 2.2: Winds experienced during Spring and Summer over Adelaide and Holdfast Bay.
Recorded at Adelaide Airport (Source www.bom.gov.au/sa/forcasts.shtml)
50
Figure 2.3: Winds experienced during Autumn and Winter over Adelaide and Holdfast Bay.
Recorded at Adelaide Airport. (Source www.bom.gov.au/sa/forcasts.shtml)
51
North and north-easterlies, blowing at speeds of 11-20km/h dominant winter winds
recorded at Adelaide airport. Winds from these directions, however, do at times reach
speeds above 21km/h (Fig 2.3). In the afternoons the winds swing and come out of the
northwest, west and southwest direction. All three of these come across the gulf straight
onto the coastal areas of Adelaide.
Tides
Tides have been recorded as having a passive role in sediment transportation. They
affect the beach zone during high tide, thus creating erosion central to this area alone
(Waddell 1976 in Davis 1985, p.403). The sand that is eroded can end up either further
along the beach or out of the beach zone completely. The sediment then has the
potential to be redistributed to any of the other zones of the coast. Tides do have some
influence on the other areas of the coastal zone. During the high and low tide, water
levels over given areas change, and in some cases can effect other actions, such as wave
power over the seabed (Davis 1985, p.406).
As well as astronomical tides, water levels in the Gulf are influenced by the flow of
water from Backstairs Passage (Tronson 1973, p.97). Tides in the Gulf of St Vincent,
however, have more than a passive role. Steedman (1974) collected data concerning the
speed and degree that changing tides could have on transporting sediment in the Gulf of
St Vincent. He found that during slack water times, there is little possibility of sediment
transportation activity in the gulf. As soon as the tide turned, the potential for turbidity
increased (Steedman 1974, p.128). The work by Waters (1982) indicated that net
sediment transport movement is caused by tidal action in association with the dominant
southwesterly winds. The sudden increase in water speed is enough to aid the process.
52
It alone, however, is not strong enough to disturb and move sediment (Waters 1982,
p.140).
Waves
Waves are the single most significant component that to sediment transportation and
disruption (Fredsoe & Deigaard 1992, p.32). Waves push the most sediment while also
having the capacity to change the configuration of the seabed and currents in the area
(Davis 1985, p.409). Waves occur when there are at least 4 kilometre per hour winds
over the water surface (Kennish 1994, p.4). As already mentioned, winds have the
potential to create larger waves, provisional on the duration, speed, and the direction of
the wind.
The direct actions of a wave are responsible for freeing sediment from the seabed
(Longuet-Higgins 1972, p.204).
This action is also responsible for movement of
suspended sediment as well. The water motion in the top part of the wave moves
vertically in an oscillating pattern, while the motion in the lower part of the wave moves
horizontally back and forth in a circular pattern (Ingle 1966, p.53). When the wave
reaches shallower water, the horizontal motion has a greater influence on the seabed,
disturbing the sediment. The back and forth motion becomes faster, and the wave
steeper. This will continue until the circular ground motion is faster than the oscillating
motion in the top of the wave, causing the wave to crash (Ingle 1966, p.53) Figure 2.4).
This force of the wave breaking is also a factor that loosens and suspends sediment in
the water. The repetitive action will also generate currents in the direction that the
waves are heading (Ingle 1966, p.59).
With the sediment set free, the constant
53
movement of larger and stronger waves over the same spot of seabed will cause more
sediment to be lifted, while the already suspended sediment can now be moved by
currents generated by wave movement (Kennish 1994, p.5).
Figure 2.4: Movement of water particles inside a wave.
Measurements and recording of wave data has not been taken in the local area around
Holdfast Bay. While this may seem to be a large gap, in actual fact it is not. In the
areas that were excavated, the action of the wave has minimal interference with the
seabed. This is due to the depth of the water over the site is 4.5 metres. At this depth
the wave needs to be at least nine metres high to become influential. This is because
half of the hight of the wave that is visible on the surface is the depth that the wave
influences underneath the sea-level; hence a wave nine metres high would be required
to affect the seabed that has four and a half metres of water above it. The currents that
they produce, on the other hand, do effect the seabed, causing sediment to be kicked up.
It is then that the action of the wave would come into play. The sediment would be
caught in the cycle of the wave motion. The strength of the waves can be deduced from
the strength of the dominant winds blowing over the water.
54
Currents
There are many different causes of currents, ranging from wind produced to tidal. In
terms of sedimentation, there is a direct relationship between the intensity of the current
and the wind speed (Davis 1985, p.413). As previously mentioned above, stronger
winds directed to shore will create waves, that will in turn creates shoreward currents
(Ingle 1966, p.86).
Currents are what bring the sediment into the shore from offshore sources (Waters 1982,
p.17). They not only deposit the sediment onto the beach, but also deposit en-route.
Longshore currents, also known as littoral drift, operate close to the shore. This current
moves the greatest amount of sediment, and for the longest distances (King 1972,
p.114).
As near-shore currents are usually in shallow water, they affect both the
sediment that is suspended in mid water and lying on the seabed.
The constant
movement of currents along the seabed can have the outcome of disturbing the sediment
deposit (Ingle 1966, p.107).
The building of jetties and breakwaters can restrict or stop the littoral drift and other
near-shore currents (Viles and Spencer 1995, p.78). They cause sediment on the up
drift side of the jetty to accumulate, while the down drift side it erodes away. These
processes can be reversed by storm action. Only a small amount is usually replenished
during storms because these events are short lived. In most cases, they still have to push
the sediment through the structure (Komar 1983b, p.192).
There has been some work done on currents and their circulation within the Gulf of St.
Vincent. Examination of these currents by Tronson (1973) and later by Waters (1982)
55
found that currents move in a clockwise pattern in the main body of the gulf. There is
also a southerly current on the eastern side of the Gulf (Figure 2.5) (Tronson 1973, p.94;
Waters 1982, p.26). It is this current that directly affects the Holdfast Bay area.
Both Tronson and Waters recorded that this pattern of currents formed when winds came out of
the southwest. This is the same wind that blows the strongest in three of the four seasons of the
year (Figure 2.2 &
Figure 2.3). Also noted was that sediment is transported up into the Gulf and onto the
foreshore on the eastern side of the Gulf during these conditions (Tronson 1973, p.94,
97; Waters 1982, p.30).
NW wind
SW wind
Figure 2.5: Currents formed from a
southwesterly wind (Adapted from Tronson
1973)
Figure 2.6: Currents formed from a nonsouthwesterly wind. (Adapted from Tronson
1973)
56
Tronson's research indicates that during other wind conditions currents coming up into
the Gulf are not as proficient in carrying sediment as the southwesterly wind and
currents are (Figure 2.6) (Tronson 1973, p.94). During storms the accompanying winds
and currents in the Gulf are the cause of the distribution and movement of large
amounts of sediment to and from the Adelaide foreshore (Waters 1982, p.117). These
four forces are the primary influences on sediment accumulation and erosion from the
different areas in the beach and near-shore zones. Other non-physical factors need to be
added to this equation of sediment movement. Fauna-turbation and the presence or
absence of seagrasses can also dictate how the sediment, and the deposit within it can be
affected.
Floral and Faunal Influences.
The impact that burrowing animals can have on an archaeological site is significant.
Ferrari and Adams (1990) investigated how feasible it was for these animals to affect a
shipwreck. These animals are attracted to a shipwreck as they offer protection and other
animals and food sources (Ferrari & Adams 1990, pp.142-145). The animals have the
potential of exposing previously buried objects to oxygenated water through building
their burrows (Figure 2.5). This in turn causes increased deterioration. Burrows can
also collapse, which allows sections of the deposit, objects included, to move
downward. The digging of burrows disturbs the immediate stratigraphy and affects the
overall stratigraphy (Ferrari and Adams 1990, pp.148, 150). All three have the potential
to change the make up and positioning of artefacts in the deposit.
57
Figure 2.7: An example of burrows that can disturb as site. (Adapted from Ferrari and Adam 1990,
p.140)
Marine angiosperms, commonly known as seagrasses, influence the seabed and the
configuration of the sediment. Seagrasses anchor themselves into the seabed. Their
root system forms a network over the site, holding down the sediment (King 1981,
pp.201 & 207). Seagrasses also promote sedimentation over the area by catching the
floating sediment as it passes (Kennish 1994, pp.304-305;). Seagrasses are important as
they bring added stability against erosion. The growth of seagrass in an area also
reduces water movement. Meadows of seagrasses cause a drag on moving water, which
slows the movement down (King 1981, p.201). These factors make the presence of
seagrasses in an area an important factor when considering the stability of sediments.
Neither seagrasses nor marine burrowing animals were present in the sections that were
being excavated around the old jetty.
Observations made during the excavation
revealed that seagrass colonies were no longer present in the environment. Divers did
notice, however, a dark grey layer near the base of each trench (Kathy Brown 2000
pers. comm., 27 Jul; Terry Drew 2000 pers. comm, 27 Jul). Within this layer were
remnants of a root system associated with a previous seagrass colony.
58
Again divers noticed during the excavation that there were few burrowing animals
within the deposits (Richards 2000, pers. comm., 6 Aug). The lack of seagrasses could
be a reason for the absence of animals in the are. Seagrasses provide a food source for
many of these creatures. The fact that there is no seagrass present in the immediate area
around the original jetty indicates that there are very few animals that are going to live
in the sediment in that area.
Other important observations made during the excavation were in relation to the
sediments. In describing the sediments excavated, people's comments have to be used
as there were no samples taken of any deposits during the course of the project.
Although many observations were made, this does limit the accuracy of the analysis.
Firstly, there appeared to have been no real difference in the compactness of the
sediment. The colour and composition of it did not change until close to the bottom of
each deposit. Near the base of each excavated area the sediment became finer, and
remnants of a pre-existing seagrass colony were uncovered (Kathy Brown 2000, pers.
comm., 27 Jul; Richards 2000, pers. comm, 6 Aug). Underneath this remnant root
system the sediment was a dark grey in colour sediment that was heavily compacted.
There were no artefacts found in or below this compact layer (Kathy Brown 2000, pers.
comm., 27 Jul).
Discussion
The theoretical and practical research completed by oceanographers and other
professionals gives clear indications that sediment deposits in coastal zones do not have
59
many opportunities to become consolidated. The occurrence of tides and tide changes
has been stated by Steedman (1974, p.128) and Waters (1982, p.140) as sufficient to
create enough energy to disrupt and move sediments. However, they also stressed that
this alone, like all other forces that have been mentioned above, are not enough to cause
a large amount of disturbance to the seabed.
Multiple environmental forces acting at the same time have a more significant influence
on sediments. In the theory presented any of these four forces could be working in
commination together.
These combinations change depending on the specific
environment of each unique coastline. The determination of these combination of
factors must be made with particular reference to the localised environment.
This is evident from the conditions that prevail in Gulf St Vincent. Tronson (1973),
Waters (1982) and Steedman (1974) all pointed out in their research that tides, currents
and waves were heavily influenced by winds in Gulf St Vincent (Tronson 1973, p.94;
Steedman 1974 p.128; Waters 1982, p.117). They all made particular reference to the
strong southwesterly winds that dominate in three of the four seasons (Figure 2.2;
Figure 2.3). With tides, the ability to create turbulence along the seabed is increased
with the waves that these winds produce (Steedman 1974 p.128). Currents capable of
moving sediments and affecting the seabed are most effective when the same wind is
active (Waters 1982, p.30). Winds from other directions were labelled as being not as
effective in disrupting and transporting sediment onto the eastern shore of the Gulf
(Tronson 1973, p.94; Waters 1982, p.30).
60
With this specific understanding about the coastal environmental energies that affect the
research area, a more focused summary can be made. The strong southwesterlies that
come up into the gulf travel across the largest body of water before hitting Holdfast
Bay. The frequency of this wind is highest in the afternoons in every season other than
winter. Averaging speeds around 20km/h, this wind has a profound affect on the
resulting waves and currents (Kennish 1994, p.4). The frequency of currents and waves
considered to be the most active in sediment erosion and distribution is also increased as
a result of this wind. Although there is no data on the size and energy of waves in the
area being researched, the fact still remains that the intensity of waves increases. This
has the result of capturing sediment that is suspended in the water and redistributed
elsewhere.
When all of these factors are taken into consideration, it can be established that the
sediment deposits making up the coastal area off Holdfast Bay are under constant stress
from the environment. Even though these environmental stresses are minor, they do not
allow the sediment on top of the seabed to become consolidated. Leaving the sediment
susceptible to stronger environmental forces. How much of deposit that is susceptible
can be deduced from observations made during the excavation.
Divers reported no great change in the sediment type through the deposit, and the ease
in which the sediment could be removed was apparent. A change did occur when the
remnants of a previous seagrass layer were uncovered (Kathy Brown pers comm., 27
Jul; Drew pers comm., 27 Jul). This was detected at approximately 40 centimetres into
the deposits in areas E, F and G. Below this level the sediment was a fine compact silt
where no artefacts were uncovered.
61
The unnoticeable change in colour and compactness of the sediment until the old root
system was reached suggests that 30 to 40 centimetres of the deposit are affect by the
environment. Rounding this figure to a maximum depth of 40 centimetres, then the
effect of disturbing and unconsolidating the sediment is occurring to a large proportion
of each deposit. This will be discussed further in chapters 5 and 6.
The importance of there being no seagrasses present and no marine life living in the
sediment deposits is also critical. As there are no seagrass meadows in the region of the
excavations, there is no protection offered to the sediments. The protection that the
seagrass can create can be seen from the sediments witnessed below the remanent
seagrass roots during the excavation. The lack of marine life in the sediments is also a
good factor as it allows for an investigation solely on the other environmental aspects
alone.
Conclusion:
Studying how individual components of the marine environment operate alone, and in
collaboration with other environmental forces is an important part in investigating
artefact movement as it allows a different insight into the formation processes of an
archaeological site. It was not until the specific environment of the Holdfast Bay area
was examined that the exact potential of the environment was known, and can now be
directly associated to this study. Once environmental influences are understood, their
impact on marine deposits can be defined, allowing for a new insight into artefact
positioning.
62
3. General analysis of the material
Before starting to describe the formation of the deposits and the specific positioning of
the artefacts, it is first necessary to talk about the artefacts themselves. What objects
were found and what they were made of is an important factor when determining the
patterns that existed in the deposits. The following section describes the condition,
completeness and other criteria associated with the material, helping to provide a
general understanding of the assemblage.
Count of Artefacts
80
72
70
60
49
53
50
40
23
30
20
10
0
0
0
A
B
0
C
D
E
F
G
Area
Figure 3.1: Count of Artefacts from each area excavated
During the excavation 197 artefacts were raised. They were found in only four of the
seven areas that were examined. Area G had the highest concentration of artefacts, with
72 artefacts from the two grids excavated (Figure 3.1). Areas E and F had a similar
amount of artefacts, with 43 and 53 respectively. There were, however, there were three
trenches excavated in area F and only two grids in area E. The remainder of the
artefacts came out of area C (Figure 3.1). The artefacts are discussed on the basis of
their fabric, completeness, function, condition, and whether they were special or
diagnostic artefacts.
63
Fabric
There were two dominant fabric types present in the Holdfast Bay assemblage. These
two groups were artefacts made of glass (97) and metal (80). The remaining twenty
items were made up of various materials, including five made of ceramic, two from
97
1
1
1
1
1
Fibre
Rubber
Shell
Stone
Ceramic
2
Clay
5
Plastic
8
Composite
80
Metal
120
100
80
60
40
20
0
Glass
Count
plastic, and eight objects that were made from a combination of materials (Figure 3.2).
F a b r ic T y p e s
Figure 3.2: Summary of artefacts showing fabric from all excavated areas.
Completeness
There were only 31 artefacts from the whole assemblage that were intact (Figure 3.3).
From the total assemblage only 59 artefacts, or 30 per cent, were considered over 50
percent complete. This includes 24 objects that were between 75-100 percent complete
and a further four that were above 50 per cent but below 74 percent complete (Figure
3.3). If the 40 objects that could not have a completeness per cent assigned to them
were disregarded from the total number of artefacts, the overall percentage of the
artefacts over 50 per cent complete is pushed up to 37 per cent. Only nine objects that
were recovered were concluded to be below 50 percent but over 25 percent. The
remaining 89 objects, or 45 percent of the total material, were less then twenty-five
64
percent complete (Figure 3.3). The 40 artefacts that had an unknown completeness
percentage were objects that also had an unknown function.
Function
It was possible to determine the primary function for most of the artefacts within the
Holdfast Bay collection. The function of each object was based on the characteristics
that each object had. Function, however, could not be designated for 45 of the objects
(Figure 3.4). These artefacts were too small, heavily corroded, or eroded to identify
their use.
100
89
Percentage
80
60
40
40
31
24
20
4
9
0
100%
7 5 -1 0 0 %
5 0 -7 5 %
2 5 -5 0 %
0 -2 5 %
U nknow n
C o m p l e te n e ss P e r c e n ta g e
Figure 3.3: Completeness of Artefacts Excavated from Holdfast Bay, 2000.
The presence of a large number of glass bottle fragments had a great influence on the
overall results from the collection. 94 of the 97 glass pieces were bottle fragments. The
other three glass pieces were fragments of a glass bowl, window glass and a glass
stopper. Bottle and glass bowl fragments were grouped together into the function of
containers Figure 3.4).
65
1
Function Unknown
Adornment
2
Lighting Device
Clothing Accessory
2
Equipment
2
Maintenance Tools &
3
Equipment
6
Food Service Tools &
6
Personal gear
9
Armament (Ammunition)
Equipment
Fishing and Trapping Tools &
11
Exchange Medium
14
6 0 .0
5 0 .0
4 0 .0
3 0 .0
2 0 .0
1 0 .0
0 .0
Percentage
45
Building Component
Count
96
Container
120
100
80
60
40
20
0
F u n c t io n T yp e
Figure 3.4 Count of functions associated with the material.
The high frequency of glass bottle fragments does not indicate that there were 94
individual bottles. There were only two complete bottles, and both were made of
ceramic. MNI figures could determine how many bottles the fragments represent.
These figures were not used in the analysis of this collection. These figures were not
used as they have a high degree of error within small collections (Klein & Cruz-Uribe
1984, p.28). The values of MNI are affected by the small sample size. The size of the
assemblage also effects the potential for using it as a comparative collection against
other excavated jetty sites (Klein & Cruz-Uribe 1984, p.28; Grayson 1978, p.55). The
MNI of glass fragments would grossly underestimate the total number of bottles that
were present in the whole assemblage. Using that figure against the other MNI values
for other materials would give disproportionate results about the amount of material
present in the collection. This effectively makes MNI results useless.
66
Figure 3.5 A Selection of Building materials uncovered from under the Pavilion/Tearooms.
Artefacts GJ 3187 (Left) & GJ 3168 (Right) (Photograph by M. Lewczak).
Other functions that were present in the collection of artefacts were associated with
people, activities that occur on jetties and with the jetty itself. Only six objects could be
classed as personal items and only two as adornment (Figure 3.4). Objects that were
associated with activities conducted on the jetty included objects from fishing and from
the pavilion/tea rooms. Fishing tools and equipment were predominantly comprised of
sinkers and berley threads. Food service and equipment articles, such as knives, were
artefacts that came from the tearooms, located at the end of the jetty.
Building
components of the jetty and its structures, such as nails and screws, contributed eleven
pieces Figure 3.5).
Figure 3.6: A sample showing the variety of artefacts uncovered from under the original jetty. A
sinker (GJ 3016) and a bullet (GJ 3037). (Photograph by C. Lewczak)
67
Figure 3.7: Example of the different conditions of glass uncovered. Note the absence of marine
growth on the right. (Artefacts GJ 3176 (Left) & GJ 3165) (Photographs C. Lewczak).
The material was not analysed discussed for each individual area, for the same reasons
that MNI values were not used, that is, the size of the assemblage was to small to begin
with. Examining artefacts from individual areas would result into an even smaller
analysis. The material that was uncovered from each trench is discussed in chapter 6.
Condition
Figure 3.8: Example of different condition of the coins uncovered at Holdfast Bay. Left GJ3136
(poor), middle GJ3191 (poor) GJ3152 (good) (Photographs S. Briggs
The condition of the artefacts could also be an indicator of the environmental influences
on the site. The overall condition of the material, not including coins, was considered to
be in a poor (46), fragile (4) or fair (26) physical state (Figure 3.9). The majority of the
objects, however, were classed in a good (107) condition, while there were also 5
68
objects in an excellent condition. Coins were not included in with the other material as
there is a separate method for scaling their condition. This is based on the same scale
used by coin collectors (Rodrigues 1999, p.26). The coin collector's scale for grading
coins is standard in Australia and can be easily be applied to other collections that
contain coins.
120
107
100
Count
80
60
46
40
20
26
5
4
0
Fragile
Poor
Fair
Good
Excellent
Catagory
Figure 3.9: Condition of the artefacts (excluding coins).
There were only nine coins uncovered during the excavation. The majority of these
were considered in a poor condition.
There were two coins that were in a good
condition, while one coin was considered in very good condition (Table 3.1).
Condition classification
Very good
Good
Poor
Count
1
2
6
Table 3.1: Coin Condition.
Diagnostic Artefacts and Special Finds
There were very few diagnostic artefacts represented in the collection. Only 15 %, or 28
objects to be exact. These were made up mostly of coins, bullets, and maker's marks on
glass fragments. A further nineteen artefacts were considered special finds. These were
69
chosen because of their uniqueness on the site. Some of the special finds included a
Yale Padlock, a range of coins dating from 1912 to 1974; and two complete ceramic
Halls Ginger Beer Bottles.
Figure 3.10: The only two intact bottles found on site (Artefacts 3055 (Left) & 3051 (Right)).
(Photographs S.Briggs & C. Lewczak)
70
4. The question of chronology on the site.
The first investigation into the Holdfast Bay material was to determine whether the
deposits were in chronological order. To determine this, diagnostic artefacts were used.
As the analysis into chronology and artefact patterning was centred on areas E, F and G,
coins will be used as the main indicator. This was due to their high frequency of coins
within these trenches, as well as the fact that their date can be taken as the earliest
possible date of deposition. In total eight of the nine coins came from these three areas.
Other diagnostic material will also be used, such as bottle fragments, which helped in
determining whether the deposits were made up in chronological order. As mentioned
earlier, these three areas were used in the analysis of chronology, and in further analysis
as they were all positioned in a row and the same distance from shore, making it
acceptable to compare their information to one another (Figure 4.1).
Figure 4.1: Map of Location of the Areas E, F and G.
There were eight coins excavated from the three areas in question. From these eight
coins, seven were found to be imperial denomination, that is, they are coins that were
used before the metric system was adopted in 1966 (Wilks 1992, p.1). The group of
coins was comprised of five halfpennies, one penny and one three pence piece. There
was one metric coin, a 1974 20 cent piece located during the excavation. The presence
71
of the 1974 coin was surprising as there has been little to no activity in this section of
water since the jetty blew down in 1948. Fishing in the area is the only explanation as to
how the coin was deposited there. However, fishing is usually concentrated on the
current jetty and the breakwater, and from personal observations there is very little to no
fish life between these two positions.
Figure 4.2: Position of the eight coins from all three trenches next to each other.
The examinations will look at each area individually first. In area E there were two
coins found. They were a 1974 20 cent coin and a 192? Halfpenny (Figure 4.2). The last
number in the date on the 192? coin is unreadable because of deterioration. The 192?
coin was uncovered at a depth of 30cm, or 3.3 metres below sea level. The 1974 20 cent
piece was found twenty centimetres below the 192? coin at 50cm. The presence of the
younger metric coin underneath the older imperial coin is a strong suggestion that the
deposit is not made up in chronological order, because these two coins were never in
circulation at the same time.
In the same trench as the 1974 coin was a fragment from a codd bottle that dated
between 1906 and 1957 found between the two coins at 40cm (Figure 4.3). The bottle
72
fragment was part of a cordial bottle that was marked with the letters "J. LADD"
(Artefact GJ 3021) (). J. LADD refers to the son of J.O. Ladd, the original owner of an
Adelaide cordial and Aerated Water Company (Hallett and Tuckwell 1993, p.111). J.
Ladd took over the company when his father died in 1882 (Hallett and Tuckwell 1993,
p.112). He did not, however, begin to put his initials on any of the company's bottles
until 1906, when they appeared on ceramic and torpedo bottles (Hallett and Tuckwell
1993, p.122). The company later folded in 1957 (Hallett and Tuckwell 1993, p.118).
Figure 4.3: J. LADD bottle fragment uncovered from a depth of 40cm, Trench E2.
Taking the earliest date for the bottle entering the deposit as 1906, and the latest date as
the date that the company folded, 1957, then it would have been deposited before the
1974 coin. As the glass fragment is located between the two coins, it offers further
support against chronological ordering of artefacts.
In area F, three coins were uncovered close to each other. The first was a 1949 half
penny found at 2.9 metres, just under the surface. A 1916 three pence piece was found
73
30 centimetres below the first coin, at a depth of 3.2 (Figure 4.2). The third was a 1942
halfpenny coin found near the bottom of the trench, twenty centimetres further below.
Figure 4.4: The three coins that were uncovered from area F's trenches: Left: 1949 Halfpenny (GJ
3101), Centre: 1916 Three pence piece (GJ3089). Right: 1942 Penny (GJ 3052). (Photographs by
S. Briggs)
The patterning of these coins as 1949, 1916 and 1942 is interesting. The ordering of
these coins is not an indicator that this deposit has been disordered. All of these coins
could have been in circulation at the same time, which means that these coins could
have been deposited in this order. The presence of the 1949 coin is also intriguing as
the jetty was destroyed by a storm in 1948 (Jeans 1979, p.158). This aside, the amount
of sediment that is between coins needs to be examined. The fact that there is 20
centimetres of sediment between the 1942 coin and 1916 coin, and a further 30
centimetres between the 1916 coin and the 1949 coin indicates that there has either been
a large deposition rate between all of the coins, or they have been moved around.
Three coins from area G were uncovered, all heavily corroded. Two were found
approximately 30 centimetres into the deposit at 3.2 metres underwater and the third
was found at 3.4 metres underwater. The only coin that could be read was a 1942
halfpenny, that was located at 3.2 metres below sea level (Figure 4.2).
74
Within this same trench there were also four more fragments of diagnostic glass, all of
which come from stubby bottles (Figure 4.5). The first (number 1 in figure 4.2) was a
stubby bottle base located at 20cm below the seabed (Figure 4.5). It had crescent
stripples, which were introduced to help move bottles along the conveyer belt, date from
1975 (Reed 1977, p.32). The second bottle fragment (3 in Figure 4.5) was at a depth of
30cm. The fragment was from the lower section of the body of the bottle near the base.
On it was embossed "aide Bottle Co.". If complete the writing would have read
"Adelaide Bottle Co.", the makers mark for the company that made the bottle, The
Adelaide Bottle Company. Adelaide Bottle Co. was first embossed on their bottles in
1969 after the company changed its name from the Adelaide Bottle Co-operative
Company, at which time they had their full name embossed on the bottle (Reed 1977,
p.32). The remaining two stubby fragments (3 and 4 in Figure 4.5) were both the neck
and finish of a bottle. The shape and style of the finishes of stubby bottles has not
changed, as they have always been crown seals. Because of this the minimum date of
deposition on the site is 1954, the year that they were first introduced (Reed 1977, p.32)
Figure 4.5: Position of diagnostic glass fragments against coins found in areas E, F and G.
75
Figure 4.6: Three of the diagnostic glass fragment uncovered from area G. Left: finish of a stubby
bottle (GJ 3141), Centre: Base of a stubby Bottle, note the crescent stripple (GJ 3110), Right:
Fragment from the body section of a stubby bottle that reads "de Bottle Co." (GJ 3105)
Discussion
There are many strong indications that the deposits excavated at Holdfast Bay were not
ordered chronologically. Firstly, in area E there was a 1974 20 cent piece located
underneath the 192? coin (Figure 4.2). The possibility that these were dropped at the
same time is considered extremely unlikely as these two coins were never in circulation
at the same time. A second possible explanation is that the 1974 coin was deposited in
the area and has worked its way down below the 192? coin.
It is more likely that the 1974 coin has moved through the sediment, rather than the
sediment in the deposit eroding away. The result of the erosion would have been that
all material up until the 1974 coin was deposited would have been located at the one
depth. This was clearly not the case. Material was found all through the deposit,
including material that had been deposited during the time of the jetty. Also the 1974
coin was found below the 192? coin, not at the same level as it. The presence of the
c.1906 bottle piece between the two coins is another indicator that the deposit was not in
76
a chronological order. It was deposited well before the 1974 coin, but was found above
this coin but below the 192? coin. This confirms the notion that the 1974 coin had to
have moved through the deposit, rather than the environment affecting the deposit as a
whole.
The two coins were similar in shape and size, meaning that they would have similar
densities. From the results that Moeyersons and Cohen (1977) produced, and from the
hypothesis proposed by Keller on the Norwegian Harbours project, it seems that this
movement resulted from the unconsolidated nature of the sediment. This theory will be
tested on all of the material from the three trenches in chapters 5 and 6. In chapter 7
coins are specifically investigated with regard to their position, and their density and
shape.
The coins from area F were not found in chronological order (Figure 4.2).
Nevertheless, this by no means indicates that the deposit had been disturbed. All of
these coins are imperial denominations, that is pre 1966, and there is the possibility that
they were in circulation at the same time as each other. The interesting observation here
is that there is a large amount of sediment in between the top and bottom coins, both of
which have 1940s dates. There were 30 centimetres of sediment between the 1949 and
the 1916 coin, and another 20 centimetres below that to the 1942 coin. There are two
possibilities as to why there is this amount of sediment between these coins. The first
possibility is that these coins were deposited in this order and a large amount of
sediment was deposited between them. The other possibility is that the deposit had
been disturbed, and the outcome was the resulting placement of the coins.
77
When all of the coins from the three areas were considered together (Figure 4.2), it can
be seen that there are no levels appearing where certain dates of coins coexist. The
position of the coins revealed that there was no chronological pattern. This does not
mean that these coins were not disturbed, as all were possibly in circulation at the same
time. All of the coins are of varying dates, but the 1974 20 cent piece stands out.
Two unknown coins were heavily corroded and show evidence of scouring over their
surfaces. This suggests that they were at one stage near the surface where they were
subjected to sand abrasion. They were, however, uncovered from the bottom of the
deposit. If it is to be considered viable for the 1974 twenty-cent coin to move through
the deposit, then this could also be applied to these two coins.
The location of the stubby bottle fragments gives further indications that the deposits
were not in chronological order. From using the date that they were first manufactured
as the minimum date of deposition, the fragments themselves were in chronological
order. Fragments 3 and 4 in Figure 4.5 have an earliest date of when stubby bottles
were first introduced, 1954 (Reed 1977, p.32). The fragment of bottle glass that came
from the body section of a bottle with the embossed writing dates from 1969 onwards,
and was found above the last two fragments. The fourth fragment found in Area G was
found above them all, which has a minimum date of 1975 to present.
When comparing the position of the glass fragments to the position of the coins further
evidence is mounted against chronological ordering of the Holdfast Bay deposits.
Firstly in Area G alone, a 1942 halfpenny was found at the same depth as the bottle base
fragment that dates from 1975 (Figure 4.5). The fact that the 1942 coin had been out of
78
circulation since Australia converted to the metric system in 1966 (Wilks 1992, p.1)
indicates that the bottle fragment had to have been deposited after the coin. A similar
anomaly was seen when the remaining bottle fragments were found to be younger than
the latest possible date that the coin could have been deposited, 1966, yet they were
found below them (Figure 4.5). The fact that one of the fragments (3 in Figure 4.5) had
to have been deposited at least 21 years after the jetty blew down, gives rise to the
notion that the deposits at Holdfast Bay were disturbed.
When applying the position of these bottle fragments to the location of the coins from
the other Areas, there is further support. Six of the eight coins within Areas E, F and G
were either at the same level or above the younger bottle fragments (Figure 4.5). There
is no possible way that all of these coins and glass bottle fragments could have been
deposited in this order. The fact that the jetty blew down in 1948 and the metric system
was introduced in Australia in 1966, means that the coins and glass fragments were not
around during the same time. The site must have been disturbed to have produced this
formation.
Conclusion
When taking into consideration the environmental data with the chronological data, a
clear statement can be made about chronology on the Holdfast Bay site. It can be stated
from the work done on coastal environments in the Gulf St Vincent, and from
observations made during the excavation that the sediment deposits in Holdfast Bay are
unconsolidated.
These unconsolidated sediments, while being unstable, have the
capability to move freely to some extent. It can therefore be said that if the sediments
79
that contained the artefacts are unconsolidated then the objects located in them also
have the ability to move.
When considering the facts pointed out above in chapter 3 dealing about chronology on
the site, the prospect of movement due to unconsolidation is apparent.
Particular
reference is made to the 1974 coin that was found below the 192? Coin. As already
discussed, the coin could have only reached the level in the deposit that it did because it
was able to work its way through the sediment. Keller in 1972 and Moeyersons and
Cahen in 1977 had the same conclusion. From the investigation into the specific coastal
environment of Holdfast Bay, a conclusion was reached that the sediment was to an
extent unconsolidated, confirming that the coin did move through the unconsolidated
sediment to reach its position.
In addition, the two coins that could not be dated due to abrasion, notably from
sediment movement. This suggests that they were once located at the top of the deposit.
They were found near the middle and lower sections of the trench (Figure 4.2). This is
further evidence to suggest that these artefacts have at some time moved through the
deposit into the lower levels that they were found in.
The question still remains as to why the 192? coin did not also move through the
sediment to that same level as the 1974 20 cent piece? Also, why were all of the other
coins were found at different levels if in fact the sediment was unconsolidated? These
questions will be addressed in the following chapters in an attempt to further qualify
whether the artefacts had the ability to move vertically through the deposits.
80
It will be assumed from this point on that the archaeological deposits being examined
from Holdfast Bay had been affected by the environment. This will be taken to the
extent of the deposit being effected enough to alter the order of the artefacts.
81
5. Results and Analysis of Artefact Patterning: Density.
With the understanding that the archaeological deposits at Holdfast Bay were not
created in a chronological order, the focus of this thesis will move onto the possibilities
for other forms of artefact patterning. The artefact patterning theories used in the
following chapters were the same proposed by Keller (1972) and Moeyersons and
Cahen (1977). All of these investigations concluded with hypotheses relating to artefact
movement and patterning.
The first of the three investigations that will be examined is related to the position of the
artefacts and their densities.
Keller believed that artefacts within unconsolidated
sediments could settle in an order related to their specific densities (Keller 1972, p.189).
The unconsolidated sediment that surrounds the objects would allow artefacts with
heavier densities to settle near the lower sections of the deposit. The smaller the
artefact's density, the less that the object would be able to penetrate through the
sediment. This would result in a pattern where artefacts with higher densities collect in
the lower sections of a deposit and the rest of the material would be placed above these
objects according to their lighter densities (Figure 5.1) (Keller 1972, p.187).
Moeyersons and Cahen offered support to this theory. Their findings showed that
artefacts could move through unconsolidated sediments (Moeyersons and Cahen 1977,
p.814). They, however, did not compare the density of each stone tool to its depth
(Moeyersons and Cahen 1977, p.814).
The following section concentrates on the
density of the artefacts in relation to their position.
Each area was investigated
separately, and then brought together in the discussion at the end.
82
Depth Below the Seabed
0
10
0.54
1.50
20
1.62
2.70
30
2.60
5.10
40
4.90
9.90
50
7.32
60
Figure 5.1: An example of an artefact pattern formed by their densities that Keller believes could
be created in unconsolidated sediments.
The three areas that will be focused here and in the next two chapters were area's E, F,
and G. The majority of the artefacts were uncovered from these three areas. As already
explained, these areas can be compared to one another because of their similar location
in the coastal area.
Area E.
Trench E1 (E13-14-16-17).
The artefacts excavated in this trench were concentrated at 30cm to 40cm below the
seabed (Figure 5.2). From within this trench 12 of the 17 artefacts were at this level,
while only one object was found at a shallower depth. Of the 12 artefacts, their density
range was from 0.71g/cm3 and 4.58g/cm3. As can be seen from figure 5.1, there were
two artefacts with a density above this range, at 6.23g/cm3 and 8.81g/cm3. Even if
these two objects were ignored, because of their high density value compared to the rest,
the range of densities is still quite large, especially so as they were located within 10 to
20cm of each other Figure 5.2).
83
Figure 5.2: The depth and density of artefacts located in Trench E1.
84
Comparing these two density ranges revealed that the range difference between the
highest and lowest density values was smaller at 40cm, that is, there was less of a
difference between them all. The range difference between the highest and lowest
values at 30cm was 3.33g/cm3, while at 40cm the range was only 2.12g/cm3 wide. The
densities within these ranges, however, were not unique to this depth. These density
values were found elsewhere in the deposit.
Examining the trench as a whole, no pattern could be seen in the position of artefacts
and their densities. Investigating the position of similar density values exposed no
segregation between the location of one particular density value to another. Artefacts
with a density between 1.51g/cm3 and 2.50g/cm3 appear on a variety of depth levels,
from 20cm into to the deposit, down to 60cm inclusive (Figure 5.2).
There were four objects with densities from 6.23g/cm3 to 8.93g/cm3 (Figure 5.2).
These objects make up 24 percent of the total artefacts in this trench. As this was a high
percentage of the total artefacts within this trench, it was not possible to regard them as
outliers. That being the case, their presence does not support artefact patterning through
density values. An object with a density of 8.81g/cm3 was located 30cm below the
seabed. Another high-density artefact was located at a depth of 40cm (6.23g/cm3),
while an object with a density of 7.75g/cm3 was recorded at the base of this deposit at a
depth of 60cm (Figure 5.2). The three varying depths, which all contained objects of
varying densities, suggested that heavier artefacts did not settle at the base of the
deposit.
85
Trench E2 (E14-15-17-18).
The second trench from this area was excavated immediately to the north of the
previous trench (Figure 10). While there was a larger number of objects found, they
were positioned in a different fashion to that of the previous trench. Although 14
artefacts came from a depth of 30cm, more artefacts were located above and below this
level (Fig 5.3). Three artefact groupings were visible in this deposit. The first of these
was between 10cm to 20cm into the deposit, and contained four artefacts. Two of these
artefacts had densities of 1.50g/cm3 and 2.65g/cm3, while the remaining two were
higher at 5.83g/cm3 and 6.43g/cm3 (Figure 5.3)
The largest collection of objects in this trench sat in the second section at 40cm. The 14
objects that were recovered from this depth had densities that were equal to or lower
than 2.46g/cm3 (Figure 5.3). 10 objects were below this value, while the remaining four
artefacts had densities above 4.62g/cm3 and 8.84g/cm3 (Figure 5.3). The variety of
densities appearing on the same level suggests that densities were not influencing the
positioning of the objects in this trench.
The third grouping of objects deeper in the deposit was a curiosity. Seven artefacts
formed this group that was approximately 20 centimetres further down than the rest of
the material at 50cm (Figure 5.3). Similar to the other sections, one artefact did not fall
into this range. Six of the seven artefacts were grouped together with densities between
2.00g/cm3 and 3.25g/cm3. Two of the seven
86
Figure 5.3: Depth and densities of artefacts from Trench E2.
87
were located at 50cm; while the remaining five objects were at 60cm below the seabed.
The separation of this grouping from the rest is seen as significant.
The fact that only these artefacts penetrated to this depth indicates that some other force,
such as the environment, affected this deposit.
Area F
Trench F1 (F1-2-5-6)
Very few artefacts were found in this first trench in area F. There were six artefacts in
all, only five, however, had measurements that related to their position within the
deposit. The one object that did not have these measurements could not be used. Two
artefacts were uncovered at 30cm and the other three were at 40cm (Figure 5.4). The
two objects at 30cm had densities of 2.13g/cm3 and 2.64g/cm3. The remaining three
objects were at 40cm registered densities of 1.00g/cm3, 3.20g/cm3 and 5.30g/cm3. As
there were few artefacts representing this trench, it can not contribute to the question of
patterning.
0
10
2 .64
Depth
20
3.20
2.13
30
1.00
5.30
40
50
60
Figure 5.4: Depth and density of artefacts from Trench F1.
88
Figure 5.5: Depths and densities of artefacts from Trench F2.
89
Trench F2 (F5-6-9-10).
A higher concentration of artefacts in this trench revealed more information than the
previous trench in area F. Objects were not discovered to have centred on any particular
depths (). Spanning a depth of 60 centimetres, objects were uncovered on each level.
There were four artefacts with densities above 6.01g/cm3. Because of a low frequency
of high-density objects, more accurate examinations could be made. These higher
density objects will still be included in the discussion as their position to one another
may provide evidence of patterning.
There are three groupings that could be made from within this trench's deposit. The
first groups of artefacts were located between 10cm and 20cm below the seabed (Figure
5.6). Five artefacts were within this section. The ranges of densities all fell between
1.64g/cm3 and 5.60g/cm3 (Figure 5.5). Taking the 5.60g/cm3 into consideration as a
part of the data, these artefacts together do not reveal any pattern that may form in
shallow trenches. The density range is too wide to suggest that any form of patterning
from these objects.
0
3.96g/cm3
10
2.24g/cm3
20
30
1.50g/cm3
40
50
60
70
Section
Section Two
Section Three
80
90
Figure 5.6 Location of the three sections showing the difference between their highest and lowest
densities
90
The third grouping of artefacts in this trench were from the deepest section of the
deposit at a depth of 60cm (Figure 5.6). This was another string of artefacts that could
indicate if there are any similarities in artefacts that gather at these depths. Only one
artefact in this group was considered an outlier.
The density of this object was
25.47g/cm3; three times higher than the next artefact in that grouping and almost 13
times higher than the Figure 5.6). This value clearly skews the results from this
investigation and was not considered in the following discussion.
The trend seen in the previous sections of the trench, of density ranges becoming more
restricted, continued here. The range of densities ran from 2.00g/cm3 and 3.50g/cm3, a
difference between the highest density and the lowest of 1.50g/cm3 (Figure 5.6).
Another object on the same level had a much higher density of 8.71g/cm3. If this is
ignored, then there is a pattern that can be seen from the density ranges that they exhibit.
The more that these objects are ignored, however, the more likely that a false pattern
may be produced.
The second grouping of artefacts were those found at a depth between 40cm and 50cm
(Figure 5.6). These objects were separated into a group as they were found in the
middle of the deposit. These artefacts had a minimum value of 1.33g/cm3 and a
maximum of 9.34g/cm3 (Figure 5.6). There were two objects that were nearly double
the density of third highest. These two densities were 8.18g/cm3 and 9.34g/cm3. If
these two objects were ignored, the density range would then be from 1.33g/cm3 to
3.75g/cm3. The range difference between these two artefacts is then 2.42g/cm3. This is
a narrower range than in the first section, which had a difference of 3.96g/cm3.
91
There were two other artefacts deeper then this group located at 80cm (Figure 5.6). The
difference of 20 centimetres from the rest of the deposit does not allow them to be
included in the third section, but it also did not allow them to form a section of their
own. It should be noted, however, that both of these objects had densities of 2.33g/cm3
and 2.44g/cm3. These artefacts were also the only ones that penetrated to this depth of
the deposit.
Trench F3 (F9-10-13-14).
The general layout of trench F3's artefacts were largely situated close to the seabed
(Figure 5.7). The overall depth of the deposit was between 2.9m and 3.2m, a total depth
of 30 centimetres. The fact that this trench only had artefacts in one general level gave
some indications as to how objects at this depth might be affected by the environment
and also by their densities. Of all the densities that were considered high, only one
could justifiably be removed. This density, 22.93g/cm3, which could not be explained.
Its presence would have pulled the focus away from the other objects in the deposit.
For this reason the object was ignored in the following discussion.
The remaining artefacts had densities that ranged from one extreme to the other. While
it can be said that the densities predominantly range from 0.50g/cm3 up to 2.50g/cm3 ,
there were also four artefacts above this range (Figure 5.7). Two of these were over
8.00 g/cm3. All four objects and their densities will be included as they appear both on
the lowest and highest levels of the trench.
92
Figure 5.7: Depths and densities of artefacts from Trench F3.
93
The mixing of low density objects with higher ones occurred predominantly at 30cm.
Although sections closer to the seabed had few artefacts, all their densities ranged from
1.83g/cm3 to 2.24g/cm3 (Figure 5.7).
One exception was made to an object that
recorded a density of 8.15g/cm3. This was located at 10cm into the deposit along with
other densities such as 2.00g/cm3 and 2.24g/cm3.
Artefacts that came from the string of objects at 30cm had a variety of densities. These
range from 0.50g/cm3 to 13.00g/cm3. Considering this trench alone, it could be said
that artefacts in this area were gathering on this horizon for a particular reason.
However, it is not the case as other trenches in this area reveal a difference picture.
Area G
Trench G1 (G1-2-6-7)
There was a strong correlation between the position of the artefacts at a depth of 40cm
and 50cm below the seabed in this trench. 29 of the 35 artefacts from this trench were
found between this depths (Figure 5.8). Only four artefacts that were found above, and
two below this main grouping. The four objects found above did not conform to any
type of density or density range pattern.
The objects range from 0.26g/cm3 to
4.36g/cm3 (Figure 5.8). As there were only four objects, they alone cannot be used to
reveal any type of patterning. The same can be said for the remaining two artefacts that
were located underneath the main band at 60cm. As there were only two discovered at
this depth, they also cannot be used to determine patterning. It should still be noted that
94
Figure 5.8: Depths and densities of artefacts from Trench G1.
95
these two objects found their way down to this level. In addition, both have highdensity values of 7.02g/cm3 and 10.19g/cm3 (Figure 5.8).
Focusing on the two large strings of artefacts, both contained artefacts with erratic
density values. The group of objects found at 40cm had densities extending from
0.46g/cm3 to 8.00g/cm3 (Figure 5.8). The density values run at close intervals from
0.46g/cm3 to 3.14g/cm3. From there a jump to 6.00g/cm3 occurs for the remaining
three artefacts. These final three values were all close together. As all three were close
to each other, they could not be classed as out-liers. The decision to leave them in
affects the range of densities that these objects had, making the overall difference
between the highest and lowest density values 7.54g/cm3.
The artefacts grouped at 3.4m were similar to those found at 3.5m. The difference was
that the range of densities was smaller, but also there were no large jumps among Figure
5.8). The total range of densities ran from 0.50g/cm3 to 4.97g/cm3. The intervals
between any two objects next to each other only once rises above 0.50g/cm3, with a
density 3.14g/cm3 (Figure 5.8). The last two densities were 4.13g/cm3 and 4.47g/cm3.
Despite this, it still remains that the difference between the upper and lower density in
this grouping was 4.47 g/cm3, resulting in a large range of densities located at a single
level.
Trench G2 (G6-7-11-12).
The arrangement of densities in trench G2 was in contrast to that of G1. Artefacts were
concentrated in the lower levels of the deposit. 16 artefacts were found at 20cm, five at
96
Figure 5.9: Depths and densities of artefacts from Trench G2.
97
30cm, and the remaining nine were at 40cm (Figure 5.9). The trench contained three
artefacts with extraordinarily high densities. These densities, 34.82g/cm3, 36.11g/cm3
and 78.70g/cm3 were definitely considered outliers as they distort the analysis. The
individual high values that do not appear together on any level and misconstrue the
overall analysis of the trench.
Objects that were located at 20cm showed a wide density range from 1.00g/cm3 to
11.14g/cm3 (Figure 5.9). This is despite seven of the 16 objects had densities of
1.00g/cm3. The density ranges between these objects did contain large jumps between
each of the artefacts; such as 2.04g/cm3 to 5.66g/cm3 and 8.46g/cm3 to 11.14g/cm3
(Figure 5.9).
Objects found at 40cm, or 3.4 metres below sea level, were arranged the same as those
found at 20cm below the seabed.
The eight objects ranged from 1.85g/cm3 to
12.63g/cm3. There were no bunches of artefacts within this group that suggested that
the artefacts with higher values, those above 3.78g/cm3, were out of place. The middle
range of these values were 2.75g/cm3, 3.78g/cm3, 4.82g/cm3 and 7.18g/cm3 (Figure
5.9). There was no continuity in the densities of these middle artefacts to suggest that
there was any ordering to them.
Discussion
There were four essential points made during the analysis of each area that need to be
addressed for the site as a whole. Keller's hypothesis that artefacts could position
themselves within a deposit according to their density is questionable when applied to
98
the Holdfast Bay data. Firstly, all trenches contained artefacts with varying degrees of
densities at the same depths as each other. For example, trench E2 had densities of
0.13g/cm3, 2.17g/cm3 and 6.80g/cm3 at a depth of 30cm (Figure 5.3). The degree of
variation between the densities was, however, different in all trenches.
Artefacts in E1 had densities that ranged from 0.71g/cm3 up to 2.83g/cm3 (Figure 5.1).
One artefact was above this narrow range with a value of 6.23g/cm3. Trench G1 is
another example where the artefact densities extended over a 40cm range from
0.46g/cm3 to 3.14g/cm3.
The three remaining values ranged from 6.00g/cm3 to
8.00g/cm3 (Figure 5.3). As it can be seen, some deposits had group of artefacts with
highly varied densities at one depth, something that was not present in the other deposit.
The spread of the density ranges, that is the difference between the highest and lowest
density values at the same depth, proved to be quite wide. As there were artefacts with
high densities included in the analysis, they pushed up the total range of densities. If
these objects were ignored then the ranges would be considerably lower. The fact
remains, however, that these artefacts were present and could therefore not be ignored.
Comparing the range of densities that appeared on one level, to other high
concentrations at a different depth in the same trench revealed a mixture of results with
the possibility of a pattern.
Observations in trench F2 showed a correlation between the depths of the artefacts and
the difference between the highest and lowest density present. When this trench was
broken up into three sections, upper, middle and lower, it could be seen that the deeper
the section of the deposit had more defined the differences between the densities
99
became. The first section of the deposit was the shallow grouping, and was between
20cm and 30cm (Figure 5.6). The difference between the highest and lowest densities
was 3.96g/cm3. The middle section of the trench, 40cm to 50cm, had a difference of
2.24g/cm3. The deepest section, 60cm, had a difference of only 1.50g/cm3 (Figure 5.6).
A similar pattern was noted in trench E1. The two artefact concentrations were at 30cm
and 40cm (Figure 5.2). There were only four artefacts at 30cm, however, the density
range was between 1.25 and 4.58g/cm3, a difference of 3.33g/cm3. The group of
artefacts at 40cm had a total of six artefacts, which registered a difference of only
2.12g/cm3.
Although the comparison was only between two depths, and a small
number of artefacts at that, the deeper of the two concentrations had a narrower the
density range. These two, however, were the only two trenches to show such a pattern.
Other areas with concentrations of artefacts at two or more depths did not produce the
same result. Trench G1 had artefacts grouped together at 40cm and 50cm below the
seabed. Both artefact groupings had the same difference between their highest and
lowest densities (Fig 5.8). The same finding was present in the results of G2. The
grouping in this trench was shallower, at a depth of 20cm and 40cm (Figure 5.9). The
two differences here were 7.49g/cm3 and 10.78g/cm3. The remaining trenches did not
have their arrangement of artefacts concentrated at different levels.
For this type of patterning to hold true, more than two trenches would have had to show
this patterning. Another factor that dismisses these groupings is the result of densities.
The densities that created these groupings exhibited the defining ranges between levels
were not unique, that is, these density values were only found in these groupings. These
100
densities were found on other objects at other levels in the same trench, as well as in
other trenches for other areas.
There are a number of reasons why these objects could have been found in this pattern.
One explanation is that the environment has disturbed the deposits, resulting in the
arrangement of the artefacts in this particular formation. It was a coincidence that they
were found in this arrangement. A second reason could be that the order of the objects
was the result of a pattern. The factor causing it, however, was not due to densities, but
some other attribute of the object.
The concentration of artefacts at certain depths within the deposits could not be
explained by their densities. As already mentioned, there were various density values
present at the one level. The levels where concentrations of artefacts were present could
represent the depth where the environment stops having an influencing the deposit.
Two trenches had concentrations of artefacts at two levels within 10 centimetres of each
other, E1 and G2. E1's depths of concentration were at 30cm and 40cm (Figure 5.1).
The larger group of artefacts was at 40cm. In trench G2 the objects gathered at 40cm
and 50cm (Figure 5.9). The highest concentration of artefacts was again at 40cm.
Trenches E2 and F2 also had a large amount of artefacts at 30cm and 40cm respectively.
These two trenches, however, also had artefacts grouped together deeper into their
deposits.
These deeper concentrations were at 50cm in both trenches, but
predominantly at 60cm in both the deposit (Figure 5.3 and Figure 5.5).
101
A concentration of artefacts at 30cm and 40cm could be interpreted as the depth at
which the sediment became more consolidated.
At this depth the environmental
influence could have been reduced, allowing the sediment to become more
consolidated. If this was true then a large percentage of artefacts should have been
found at 30cm to 40cm into each deposit, with only a few below. In trenches E2, F2
and G2 the artefacts appear at a depth of 50cm and 60cm (Figure 5.3, Figure 5.5 and
Figure 5.9). As objects were present in these three deposits lower than the 30cm and
40cm, this indicates that artefacts were not collecting at these depths because the
sediment was considerably more consolidated.
If the concentrations of artefacts were caused by a variation in the sediment type then
these levels could be used to investigate the possibility of density patterning. The
sediment in the higher sections of the deposits, between the seabed and 30cm below,
may have been too disturbed for any type of pattern to form and settle. If, in fact, the
sediment below 30cm was influenced less by the environment, then this section may
provide the best evidence for patterning to occur. This, however, was still not the case.
While it can be said that the densities in these deeper sections were generally lower,
there was still a high enough frequency of objects with larger densities that do not allow
them to be ignored. Trench F2 had artefacts at 60cm with densities that reached
2.00g/cm3, 2.63g/cm3, 3.50g/cm3 and 8.71g/cm3 (Fig 5.5). In G1 the densities of
objects present at the same depth ranged from 0.50g/cm3 to 4.93g/cm3. Trench E1 had
a concentration of artefact at 50cm with densities between 4.45g/cm3 and 8.93g/cm3
(Figure 5.2). At 60cm the density of objects were 2.42 and 7.45g/cm3
102
If this section of sediment was more stable than the sediment above it, then there is still
no evidence of patterning of the objects as a result of their densities. Another important
factor was that not all trenches had concentrations of artefacts at deep levels within their
deposits. F2 showed a large group of artefacts deep in its deposit, while the trench
immediately next to it, F3, had no artefacts concentrated below 30cm (Figure 5.5 and
Figure 5.7).
This again could have been caused by different factors or attributes
associated with these artefacts. Whether the material type influences the artefacts
positioned in the deposit will be examined in the next chapter.
Conclusion
From analysing the position of the artefacts in relation to their densities there was little
evidence to support any claim of artefact patterning. While there were indications of
potential patterns forming, the amount of evidence supporting these claims from within
the Holdfast Bay data alone was minimal.
103
6. Results and Analysis of Patterning: Material type.
The second of the investigations into artefact patterning within deposits centres on the
material that the artefacts were made from. This specific investigation was again based
on the theories from previous research into the movement of artefacts. Keller suggested
that to further refine any examinations of artefact sorting, a focus should be placed on
the materials that the artefacts were made from (Keller 1972, p.189). Artefacts made
from the same material type were expected to have similar densities as each other.
Keller believed that this could enhance any particular pattern that was observed through
the analysis of the artefact's densities.
The research conducted by Moeyersons and Cahen (1977) was an investigation into
only one material type, stone. Their experimental investigation showed that artefacts
could move in unconsolidated sediments was further reinforced by the fact that they
were investigating the one material type (Moeyersons and Cahen 1977, p.814). The fact
that they did not take into account the densities of the artefacts is irrelevant, as the one
material type that was being investigated would have the same density.
Their
conclusions were that the one material type that they examined had the ability to move
through unconsolidated sediments (Moeyersons and Cahen 1977, p.815).
The small experiment by Stockton during the excavation of a cave revealed a similar
finding (Stockton 1973). By depositing red glass in a shallow deposit and then having
people walking over it during the normal course of a days work, Stockton found that the
glass penetrated further down the sediment than it was placed the day before. The fact
104
that only the one material type was used, red glass represents an investigation of objects
that have the same density.
The following chapter examined the position and depths of artefacts in relation to the
material that they were made from. By examining the material types individually,
indications of patterns forming within one trench could then be addressed across all
areas. This would give an indication whether the pattern seen in one trench or area was
constant to what was seen in the other trenches or areas. Again only those areas that
were examined in the first investigation will be used here. An overview of all three
areas is presented first, and then an observable pattern will then be investigated in the
individual trenches. Patterns that were observed in the previous investigation into
artefact densities were further examined in this investigation.
The groupings of
artefacts at these levels, and the density ranges that were witnessed and could not be
explained were analysed to see if these groupings were caused by material type.
The two general materials that the artefacts excavated from Holdfast Bay this year were
made of glass and metal. There were four types of glass, green, brown, blue and clear.
Within the metal grouping, there were also four main groupings. These were objects
made of lead, iron, brass and alloy. Brass was not included into the alloy category as it
could be positively identified from the other alloy composites. There were a number of
artefacts that were made from materials that could not be positively identified. This was
due to deterioration or large amounts of concretion. These objects were classed as
unknown.
105
Overview of Three Areas together
From examining all three areas together, the most frequent material was glass with a
count of 80, while there were 63 metal fragments. The highest count of any specific
material type was brown bottle glass with a total of 37, closely followed by artefacts
made of lead (25) (Figure 6.1).
The other main materials uncovered during the
excavation were clear glass and green glass, with count of 24 and 16 respectively.
Objects made of alloy fabrics totalled 18 (Figure 6.1). The remaining materials were
brass (9), iron (10), blue glass (1) and copper (1). These, however, did not occur
frequently enough to enable any in depth analysis of their relative positions in the
deposit.
Co un t o f m a t e r ia l p r e se n t in t h r e e e x a m in e d a r e as
37
40
35
30
Count
25
24
25
20
18
16
15
10
9
10
5
3
1
Lead
Iron
Copper
Brass
Alloy
Glass
Green
Clear Glass
Glass
Brown
Blue Glass
0
M a t e r ia l
Figure 6.1: Count of material types from artefacts uncovered in areas E, F and G.
The location of these two main material categories within the deposits was similar to
each other. There was a striking difference, however, with the relative count of each
one at different depths. Metal fragments were dominant at 30cm and 40cm below the
seabed, or approximately 3.3m to 3.4m below sea level (Figure 6.2). The count of metal
objects is comparatively small, with 12 occurring at 20cm, as compared to 15 and 16
artefacts at a depth of 30cm and 40cm respectively (Figure 6.2). The count of metal
106
objects in the deeper sections of the trenches at 50cm was 10, and a further 8 were
located at 60cm. The final two metal artefacts out of the three areas being examined
were at 10cm below the seabed (Figure 6.2). From these frequencies it can be said that
the metal objects found were spread between the depths of 20cm to 60cm below the
seabed.
18
16
16
15
14
12
12
Count
10
10
8
8
6
4
2
2
0
0
70
80
0
10
20
30
40
50
60
D ep th
Figure 6.2: Depth and frequency of objects made of metal from areas E, F and G.
The same can not be said about the location of all glass fragments that were uncovered
in areas E, F, and G. There were two depths where the majority of the glass was
located. These were at 30cm and 40cm. The count of glass artefacts was 22 and 26
respectively (Figure 6.3). These 48 glass objects represented 60 precent of the total
glass present in these three trenches. The next most frequent depth of glass was at
50cm, where the count was only 11 (Figure 6.3). The number of glass fragments that
were uncovered at the other depths included four at 10cm, six at 20cm and nine at 60cm
below the seabed. Two glass artefacts were found at a depth of 80cm, or 3.8m below
sea level (Figure 6.3). There is clearly a pattern emerging where glass was settling
within these trenches at 30cm and 40cm.
107
Examining the location of specific glass types to depths revealed that not all glass
follows this pattern. Brown glass had a similar pattern to that witnessed for all glass
types together. At 30cm and 40cm, where the majority of glass was found, the total
count of brown glass was 27 out of the total 37 brown glass objects in these trenches
(Figure 6.4). All other depths did not contain more then three brown glass pieces.
There were five artefacts found above and below the main band of 30cm to 40cm
(Figure 6.4).
30
26
25
22
Count
20
15
11
9
10
6
4
5
2
0
0
10
20
30
40
50
60
70
80
70
80
Depth Below seabed (cm)
Figure 6.3: Count of glass made objects from areas E, F and G.
16
14
12
Count
10
8
6
4
2
0
10
20
30
40
50
60
D ep th (cm )
Figure 6.4: Frequency of brown glass objects from areas E, F and G.
Green and clear glass fragments, conversely had no such clear formation (Figure 6.5).
Green glass had a high occurrence of fragments from 30cm to 50cm. At 30cm the count
was six pieces, while at 40cm and 50cm there were five green glass pieces on each level
(Figure 6.5). At 60cm the count was close to these two with four pieces. The remaining
108
were found between 10cm (1) and 20cm (2), as well as one artefact at 80cm. Clear
glass was most frequently found at 40cm to 60cm (Figure 6.5). There were fewer
pieces positioned between these two depths. Only two clear glass objects were at a
depth of 50cm. The same can be said for the presence of clear glass in the first 30cm.
Five artefacts were located here were made of clear glass, however, three were found at
30cm, in addition to one each at 10cm and 20cm (Figure 6.5).
7
6
Count
5
4
C le a r G la s s
3
G re e n G la s s
2
1
0
10
20
30
40
50
60
70
80
D e p th B e lo w S e a b e d (c m )
Figure 6.5: Count of clear and green glass fragments uncovered from each depths.
Only lead and alloy had a high enough frequency to allow for investigations. These two
types of metals revealed two different patterns. The objects that were made of lead
were mainly positioned in the first half of each trench (Figure 6.6). There were eight
artefacts found at depths of 20cm and a further seven 30cm below the seabed. The 15
artefacts made of lead represent 60 percent of the total objects made from lead (25).
The deeper sections of the deposits had nine lead fragments. Four were located at both
40cm and 60cm, while the one remaining piece was found at 50cm (Figure 6.6).
109
Count
9
8
7
6
5
4
3
2
1
0
10
20
30
40
50
60
D e p t h B e lo w S e a b e d (c m )
Figure 6.6: Count of objects made from lead uncovered from each depth.
Objects made of an alloy, excluding brass, showed the highest frequency in the middle
of the deposit with seven at a depth of 40cm. At 30cm there were four artefacts, while
at 50cm there were a further three alloy objects (Figure 6.7). Four other objects made
from alloy were found between 10cm (1) and 20cm (2) as well a single piece at 60cm
(Figure 6.7).
8
7
Count
6
5
4
3
2
1
0
10
20
30
40
50
60
D e p t h B e lo w S e a b e d
Figure 6.7: The count of objects made from an alloy uncovered from each depth.
The plotting of material types has not shown any positive patterning. Brown glass was
similar to the overall pattern of glass fragments in the three areas being examined,
however, green and clear glass did not. The same was seen within the metal fragments.
There was a large grouping of artefacts from 20cm to 60cm in the general pattern.
110
When the investigation excluded all but lead and alloy made objects, there was a large
difference with their frequencies at the different levels within the deposits.
The
investigation will move into the individual areas and trenches to further analyse where
material was located. Through this the pattern that each artefact type forms can expose
whether they appear in all trenches or were only present in very few.
Area E
Trench E1(E13-14-16-17)
As can be seen in figure 5.2, there were two levels in the deposit where the artefacts
were concentrated. These were at depths of 30cm and 40cm (Figure 6.8). These two
levels were predominantly glass. At the depth of 30cm the collection included four
brown glass fragments and one lead object. At 40cm, there were eight artefacts, four
brown and one clear glass fragment. The other three objects at this depth were made of
lead and copper (Figure 6.8).
Of the artefacts present between 30 and 40cm, none were exclusive to this depth band.
Eight of the 10 brown glass fragments came from within the 30cm and the 40cm range.
The two remaining pieces were located below it at a depth of 50cm, and above at 20cm
(Figure 6.8).
Other material types within the main groupings also had objects
positioned
111
Figure 6.8: Depth and material types of artefacts found from Trench E1.
112
Figure 6.9: Depth and material types of artefacts from Trench E2.
113
outside this concentration.
Artefacts that were made from lead and clear glass
fragments, which were present between 30 and 40cm, were also found at depths of
50cm, as well as another object made from alloy was located at 40cm (Figure 6.8). The
presence of material types outside the large concentration of artefacts between 30cm
and 40cm suggests that the material did not cause this grouping itself.
Trench E2 (E14-15-17-18)
There was a large presence of glass uncovered within this trench. The type of glass that
was included within the deposit, however, was not dominated by one type. There were
five brown, as well as five green glass fragments along with four clear pieces (Figure
6.9). The other material types that artefacts were made
Area F
F1 (1-2-5-6)
Like the analysis of
artefact densities in chapter 5, there were too few artefacts
uncovered in this trench to allow any meaningful investigation. There were six objects
in all, two were made of alloy and brown glass, one from green glass and one from
ceramic (Figure 6.10). These were all uncovered between 30cm and 40cm.
F2 (5-6-9-10)
This trench contained the highest concentration of artefacts, as well as the deepest
deposit of all the trenches excavated.
The deposit was again dominated by glass
fragments. Only seven of the 28 objects were made of some type of material other then
glass. Two of these objects were made from iron, another two from ceramic, while
there was single representations of lead, brass and one unknown Figure 6.11). Green
glass stood out from all other glass types numbering 11 of the 21 glass fragments.
114
These glass fragments were all found at depths between 20cm and 80cm into the deposit
(Figure 6.11). Brown glass was the next most frequent type of glass with seven pieces.
Depth Below Seabed (cm)
The final three glass pieces were all clear fragments.
50
40
30
20
10
0
3054
3053
3052
3051
3050
3049
C atalo g u e N u m b er
Figure 6.10:Depth and material types of artefacts from Trench F1.
The only material type that could be investigated were artefacts made of glass. This is
due to the low frequencies of other material present in the deposit. As already stated,
green glass was found throughout each level in the deposit from 20cm down to 80cm
(Figure 6.11). There were only three clear glass fragments, located between 30cm and
60cm. Of the seven brown glass pieces, five of them were concentrated between 30cm
and 40cm. The remaining two fragments were found at 60cm and 80cm (Figure 6.11).
While examining the artefact densities the deposits was divided into three sections (see
chapter 5) (Fig 5.6). The three sections revealed that the density ranges became more
defined the lower into the deposit. These concentrations, however, were not produced
by
115
Figure 6.11: Depth and material types of artefacts from Trench F2
116
unique density values specific to these particular depth. The same groupings were used
to determine whether the result was enhanced by material type or coincidence.
Depth Below Seabed (cm
90
80
70
60
S3
50
S2
40
30
20
S1
10
0
Artefact #
Figure 6.12: Depth and material types from Trench F2 showing the three different depth sections.
The first section comprised of artefacts between 20cm and 30cm (Figure 6.12). Both
green and brown glass bottle fragments were present. The second section was made up
of artefacts in between the levels of 40cm and 50cm. The artefacts that fell between
these depths again included glass fragments, with four green and two each of brown and
clear. There were also two ceramic and one iron debris fragments (Figure 6.12). The
third section of the deposit was at 60cm below the seabed, or 3.6m below sea level.
There were five glass fragments, three green, and one each of brown and clear. Also on
this horizon were three metal objects, one each of brass, lead and iron, but also one
unknown fragment (Figure 6.12). The mixture of material types, not only between the
two fundamental groups, glass and metal, but also between the different types of glass
and metal types does not support the viewed that these groupings were formed from a
pattern/sorting effect within the deposit.
117
F3 (9-10-13-14)
A very shallow deposit, this trench contained at least one of every material type present
in the collection except for blue glass (Figure 6.13). The main assemblage of artefacts
within this deposit lies at 40cm below the seabed, or approximately 3.3m below sea
level. On this horizon there were only two objects made of glass, both green, that were
found. The rest of the objects were made of metal (9) and shell (1). The dominant
metal elements that were present consisted of four lead objects, two alloy, two brass
objects and one iron fragment (Figure 6.13). The grouping of artefacts at this level in
the deposit was varied. While metal objects were the dominant material type, the
specific metal types exhibited no form of patterning. It would appear that only heavy
material types were moving their way through the sediment if not for the presence of the
shell bead and glass bottle fragments found on the same level (Figure 6.13).
The remaining six objects were positioned higher in the deposit. Of these six objects,
five were made from glass and one of metal. The one object made of metal, an alloy,
was positioned just below the seabed along with two brown glass fragments. A third
brown glass piece was found at 30cm, or 3.2cm below sea level (Figure 6.13). The
remaining three glass objects were a green and clear glass fragment at 10cm below sea
level and another clear glass bottle fragment at 20cm, or 3.1m below sea level (Figure
6.13).
118
Figure 6.13: Depth and material type of artefacts from Trench F3.
119
Area G
G1 (1-2-6-7).
The distribution of artefacts within this trench were between 40cm and 50cm below the
seabed (Figure 6.14). This can be seen more clearly in figure 5.5 where the artefacts are
placed according to their depth positions and not in the order that they were excavated.
This trench was evenly distributed with glass and metal fragments. Of the glass, green
and brown were again predominant with five and six fragments respectively. There
were three clear bottle fragments in addition to two blue pieces (Figure 6.14). The
metal objects were divided up into seven alloy pieces. Five iron fragments, three brass
and one lead (Figure 6.14).
Examination of the large groupings of artefacts did not indicate any specific material
type collecting at one particular horizon. At 40cm, there were 16 objects containing
four green and three brown glass fragments and five alloy pieces. Also included were
two objects made of iron and one each of clear and blue glass (Figure 6.14). There were
more material types at 50cm, where 13 artefacts were uncovered. These were three iron
objects, two each of brass, clear glass, and alloy, and one each of green glass, lead,
ceramic and rubber (Figure 6.14). As with the concentration of artefacts at 40cm, there
was no pattern observed between the location of these objects and the materials that
they were made from.
120
Figure 6.14: Depth and material type of artefacts from Trench G1.
121
Brown glass was again found in the deposit up to a depth of 40cm. This is with the
exception of only one piece located 10cm deeper (Figure 6.14). Green glass, on the
other hand, was centred between the depths of 40cm and 50cm. Other material types
were also concentrated between 40cm and 50cm. All five iron fragments, as well as
seven of the eight alloy fragments. The remaining alloy fragment was at a depth of
80cm, a difference of 30cm from the rest of the pieces (Figure 6.14).
Two other material types that stood were a sharpening stone (GJ 3109) and a piece of
rudder from the heel of a shoe (GJ 3112). The heavy sharpening stone was at a depth of
20cm, while the smaller rubber heal was 30cm further below (Figure 6.14). These two
varied differently in material types, weight and shape, and were found approximately
30cm apart. The heavier object was found much closer to the surface than the rubber
heal. Keller's theory suggested that these two artefacts should be around the other way.
This will be considered later in the discussion section.
Figure 6.15: Artefact photograph of the sharpening stone (GJ 3019) and section of a rubber heal
(GJ 3112). (Photographs by S. Briggs).
122
G2 (6-7-11-12)
Trench G2 was dominated by metal objects (Figure 6.16). Only 10 of the 31 recorded
artefacts were not made of metal. These 10 objects comprise of four brown, one clear
and one blue glass fragment, as well as four unknown materials. There were four
objects were disregarded from this trench's analysis. These four did not have any
recorded depth measurements from within this deposit and subsequently could not be
used. The depth of the deposit's artefacts were between 20cm and 40cm below the
seabed (Figure 6.16). Over 50 percent (17) of the material was uncovered at a depth of
20cm. The eight remaining artefacts were grouped together at a depth of 40cm, while
the last four were between these two groupings at 30cm (Figure 6.16).
The artefacts that were concentrated at 20cm, or at 3.2m below sea level,
were
collections of nine lead objects, two alloy and one iron. There was also one item each
of brass and clay, as well as four unknown materials (Figure 6.16). The concentration
of artefacts at 40cm was a complete contrast to the earlier grouping. Objects here were
more of a combination of glass and metal. There were four brown glass and one clear
glass fragments, along with two alloy and two brass objects (Figure 6.16). The objects
between these two levels at 30cm below the seabed comprised of two glass fragments,
one clear and the other blue; while the remaining three pieces were of alloy (two) and
one iron fragment (Figure 6.16).
123
Figure 6.16: Depth and material type of artefacts from Trench G2
124
Discussion
Three key observations were made during the investigations of each trench. These need
to be applied to the other trenches in order to make a more conclusive analysis of the
data. The first focal point was the concentration of artefacts at particular levels in the
deposit. There were a number of groupings of objects at particular levels in various
trenches. Trench E1 had artefacts concentrated at two depths, 30cm and 40cm into the
deposit (Figure 6.8). There were five objects at the depth of 30cm. The groups of
artefacts at 40cm comprised of four brown and one clear glass fragment, as well as two
objects of lead and one of copper (Figure 6.8). As it could be seen, the only dominant
material type was brown bottle glass.
G1 also had two concentrations of artefacts at a similar depths. The two collections
were at 40cm and 50cm (Figure 6.8). There were 16 objects located at the depth of
40cm. These included five alloy, four green and three brown glass fragments, along
with two iron, one clear glass and one blue bottle glass pieces. The mixture of material
types continued in the next grouping at 50cm. The 13 artefacts incorporated materials
of iron (3) and brass (2), green (1), clear (2) and brown (1) glass fragments, as well as,
alloy (2), ceramic (1) and rubber (1) (Figure 6.8).
These two trenches alone reveal the presence of a large number of artefacts on the one
level that were not made from a specific type of material. The large amount of varied
materials present, not only between glass and metal but also that the various types of
glasses and metals, indicates that these groupings were not caused by the accumulating
of a specific material type. Similar conclusions could be reached from the finds from
trenches E2 and F3.
125
The concentration of artefacts in E2 was at 30cm, and a smaller grouping at 60cm
(Figure 6.9). At the 30cm horizon there was at least one of every glass and metal type,
while at 60cm there were only three glass and two metal fragments (Figure 6.9). In
trench F3 the objects collected at 30cm into the deposit, or 3.3m below sea level (Figure
6.13). This level was dominated by metal objects. There were four lead, two each of
alloy and brass made objects, as well as one iron fragment. Without taking the other
materials into consideration, it could be stated that only heavy objects collected in the
lowest levels of the deposits. This is not true as there were also two fragments of glass
and one object made of shell.
The second point in the discussion of whether artefacts could have patterned themselves
according to their material type. The location of individual material types through the
deposits may indicate whether certain material types were themselves forming patterns
within the deposits.
From the four different glass types recorded in these three areas, there was one kind of
glass that showed some form of patterning. The glass in mention was brown bottle
glass, which was well represented in these areas with 37 fragments. Of these pieces,
there were 32 fragments that were found below the depth of 30cm below seabed level.
27 of the 37 brown glass fragments came from between a depth of 30 and 40cm. The
remaining five brown glass segments were located at depths of 50cm (3), 60cm (1) and
80cm (1). These five artefacts below 40cm represents 13.5 percent of the total brown
glass fragments. There were three objects that were uncovered at a depth of 20cm, with
the other two brown glass objects at depth of 10cm. The 27 of the 37 brown glass
126
fragments were found between these two depths, which constitutes 73 percent of the
total brown glass fragments found in these three areas.
No similar pattern was seen in the other glass types. The distribution of clear glass was
scattered between all levels, but particularly between a depth of 30cm and 60cm . The
same can be said about green glass. It ranged in depth from 10cm in to a deposit in
trench G2 to depths of 60cm in E2 (Figure 6.9). It is harder to distinguish any type of
positioning that was as clear as the position of the brown glass fragments. The span of
the green and clear glass fragments was over the 30cm to 40cm depth range, accounting
for 50 percent of the total depth range within the deposits.
Of the objects made from a specific type of metal, there were none that showed any
particular patterning within the deposits. Examining the objects made from lead, there
was clearly no one particular depth at which they collected. While lead appeared to
concentrate in the upper sections of the deposits, when the assemblage was examined as
a whole, the examination of which trench did not support this. Lead objects were
scattered at all depths. In trench E1 objects made of lead were at depths of 30cm to
50cm inclusively (Figure 6.8). In the immediately adjacent, E2, the position of the lead
objects varied from one at a depth of 10cm, two at 30cm, and an addition to two further
objects at 50cm (Figure 6.9).
In G2 the majority of artefacts were found in the lower sections of the deposit. In this
trench there were eight objects of lead at a depth of 20cm. Another four lead made
objects were found at 20cm into the deposit in trench F3. These were the only two
trenches where there was a large concentration of lead artefacts at one depth. The other
127
trenches containing lead objects were scattered at various depths. This implies the
pattern of lead concentrates at shallow depths in the deposits is not a true pattern as it is
not constantly found in the other trenches in other areas.
The same inconsistency was seen with the position of objects that were made of an alloy
material other than brass. The overview revelled that the majority of alloy made objects
were at a depth of 40cm below the seabed. In trench G1, there were five alloy artefacts
at this depth, but there were also another three above this. In F3 there were three
artefacts at 30cm into the deposit but none at 40cm (Figure 6.13). In all other trenches
there were very few objects that were made from alloy. These similarities posed a
problem of how to compare one trench to another when there were few in the one trench
to begin with. The concentration of alloy objects at 40cm, however, seems only have
occur from the few located at this depth in trenches where they were the only alloy
objects present, such as in trench F1. In trenches where there are multiple artefacts
present that were made from an alloy, they are found at a multitude of depths. For this
reason it can not be stated that alloy objects from within these three areas formed of a
pattern caused by material type. There was no pattern observed at all in the positioning
of alloy objects.
Iron fragments were located sporadically throughout the deposits. In G1 (Figure 6.14)
they were at depths of 40cm and 50cm, and in G2 at depths of 20cm and 30cm below
the seabed (Figure 6.16). In trench F2 artefacts made of iron were again found in deep
sections of the trench at 50cm and 60cm. In trench F3, however, there was an iron
fragment in with the large concentration of artefacts at depth of 30cm (Figure 6.13).
Once again the varying number of iron objects were located does not support any
128
patterning theory.
The lack of iron fragments that were uncovered in these three
trenches may also have played a role in the indefinite nature of result.
It is difficult to find any pattern that suggests that artefacts settle in unconsolidated
sediments according to their material type. There was a strong suggestion that brown
glass fragments may from a pattern. As this was the only material type that exhibited
any special formation it is even harder to state that objects in unstable sediments sort
themselves according to their material type. The size and the shape of the artefacts have
yet to be taken into consideration. These attributes may or may not help support artefact
sorting within deposits. This will be the focus of chapter 7, where only one particular
artefact type will investigated.
129
7. Analysis and Results of Patterning: Coins.
The final analysis focuses on coins excavated from the Holdfast Bay this year. As with
the previous two investigations, this examination is based on some aspects of previous
investigations
Keller and the Norwegians Museum work in harbours was the project
from which the hypothesis for this investigation was drawn. This type of investigation
was similar to that already conducted in chapter 6 regarded material types. As already
mentioned and discussed (chapter 6), Keller believed that certain material types should
be included in an investigation of artefact patterning. Proposed were three material
types, ceramics, bone and glass, as well as one artefact form, clay pipes (Keller 1972,
pp.188-189). These were chosen because they were the most common types uncovered,
and all had a small standard deviation away from their mean density. A small standard
deviation suggested that the majority of the material was grouped closely to the mean
density of the material in question (Drennan 1996, p.29).
The suggestion that clay pipes should be examined is taken to mean that many specific
artefact types should be investigated. Coins were the only artefact type that could be
used.
All other artefact types varied greatly in size and shape.
There were few
variations in the manufacturing of them, as well as few variations in their mean
densities. The following section will explain the use of coins, as well as the results from
the investigation into their positioning in relation to each other.
Such a small
investigation enabled a clearer understanding into whether objects with specific
densities, shapes and sizes were factors that lead to artefact patterning within
unconsolidated sediments.
130
The decision to use coins was set on the basis that they were the only standard type of
object produced. Duet to the strict guidelines set into the manufacturing of coins, they
were made the same way every time. The only exception to coins were the dates
stamped on them. Coins were also used because they were 100, or close to 100 percent
complete. As all were 100 percent complete, a standard investigation could be made.
Also, coins were frequent in areas E, F, and G. The only other artefact type that could
have been used was sinkers. Although sinkers were frequent in all of the three areas,
they were not standardised. Many sinkers were home made, as well as commercially
manufactured. A few of the sinkers also contained burly threads. The varying shapes,
sizes and added appendages meant they varied largely from each other, leaving only
coins as a possibility of use in this investigation.
The position of the coins in relation to each other has already been discussed in chapter
3. The positioning of the coins was an important part in determining whether the
deposits were created in a chronological order.
Figure 7.1 shows the location of
identified coins. There were two other coins found in areas E, F, and G. These,
however, could not be positively identified as coins and could not be used in the
analysis..
The coins present in the three areas were not all located at one depth (Figure 7.1). They
vary in depth from 10cm to 60cm. Figure 7.1 also shows the specific type of coin and
their individual density.
Similar types of denominations have similar densities,
allowing them to be comparable. Unfortunately only the halfpennies were the only
denomination to be represented by more then one. Despite this, the size and densities of
the coins could further enhance the findings of the previous two investigations.
131
The arrangement of densities of the coins did not exhibit a pattern. A coin at 10cm
below the seabed had a density of 8.15g/cm3, while a coin at 40cm had a density of
5.30g/cm3. At a depth of 30cm there were two coins with the densities of 4.41g/cm3
and 8.84g/cm3 (Figure 7.1). This confirms that the positions of artefacts were not
affected by their individual densities, as seen in chapter 5.
0
Hp
10
Depth Below Seabed
8 .1 5
20
Tp
Hp
30
4 .4 1
8 .8 4
P
40
5 .3 0
2 0 C e n t p ie c e
50
8 .9 3
Hp
60
1 0 .1 9
70
Figure 7.1: Position of coins from areas E, F, and G showing the density and coin type. (P=Penny;
Hp=Halfpenny; Tp= Three pence piece).
As the coins did not appear in any particular pattern, the size of the coins was
investigated. Although there were many different denominations, the different sizes of
the coins could propose another attribute that influences the movement of an object.
Table 7.1 shows the different coins that were recovered along with their diameters. The
halfpennies had a diameter of approximately 25mm. The 20-cent piece was similar in
shape to the halfpennies, with a diameter of 28mm (Table 7.1). The one penny had a
diameter of 31mm, while the three pence piece had the smallest with a diameter of
17mm.
132
Artifact #
Coin
Depth in Deposit
GJ 3101
GJ 3089
GJ 3035
GJ 3052
GJ 3015
GJ 3111
1949 Half penny
1916 Three pence
192? Half penny
1942 Penny
20 Cent Coin
1942 Half penny
10cm
30cm
30cm
40cm
50cm
60cm
Diameter (mm) Density (g/cm3)
25
8.15
17
4.41
24
8.84
31
5.30
28
8.93
25
10.19
Table 7.1: List of coins present in the areas E, F, and G with their corresponding Diameter and
Densities.
Examining the position of the three halfpennies reveals that they were located at
different depths in the trenches. Two were found in the lower sections of the trench at
10cm and 20cm, however, the third halfpenny was at a depth of 60cm (Figure 7.1).
This further supports the statements made in chapter 6 that there was no evidence for
the metal fragments forming any type of patterning in unconsolidated sediment.
The densities that were associated with these halfpennies, however, were in sequential
order. The halfpenny at a depth of 10cm had a density of 8.15g/cm3; the halfpenny at
30cm had a density of 8.84g/cm3 and the third halfpenny had a density of 10.19g/cm3
(Figure 7.1). All of these coins have the same shape, and were made the same way.
Nevertheless, their densities differ slightly from each other, which could have been the
resulting factor in the potential formation of a pattern. The two limitations to this
statement are that these were the only coins that appear more than once in these three
sections and that three of these coins show this formation. There were other coins in the
collection with similar diameters to the halfpennies. The 20-cent piece had a diameter
of 28mm and was located at a depth of 50cm (Figure 7.1). Its density was 8.93g/cm3
and fitted between the second and third halfpenny's density values. The one penny that
was uncovered at 40cm below the seabed had a diameter of 31mm (Table 7.1). Its
density did not fit the sequence formed by the other four coins. With a density of 5.30
133
g/cm3, the penny throws doubt onto the ordering of the coins. Whether this coin was an
outlier in the deposit can not be stated for certain as there was only one penny found in
all the areas that were examined. The fact that the was only one 20 cent piece present in
the deposits can not be taken as support for a formation of the pattern for the same
reasons that the penny can not be conclusively used.
There seems to be no supporting evidence that the shape of the artefacts could be a
potential attribute in influencing the movement of coins.
The sizes of all three
halfpennies were the same yet they were found at different levels within the deposit
(Figure 7.1). The 20-cent piece and the penny were also a similar size and shape. Yet
these were also found on different layers to each other. The only small coin was the
three pence piece located at 30cm. This was on the same horizon as a halfpenny (Figure
7.1). Even with a smaller diameter of 17mm, the smaller coin did not penetrate lower
into the deposit.
Discussion
The examination of one specific artefact type, coins, revealed very few conclusive
results. The position of particular coin types, such as halfpennies, were not located in
any relative positional pattern. These objects, having similar size and shape, could not
support the possibility that artefact patterning was occurring in unconsolidated
sediments. Admittedly, only halfpennies could be investigated, as they were the only
coin types of which these were more than one. This did pose a problem to the whole
analysis.
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The densities of the coins did appear to offer an explanation for their specific position.
The halfpennies were found in a sequential order running from the lowest density at the
top of the deposit down to the highest density at the bottom (Figure 7.1). This could be
taken as the start of a formation of a pattern. Considering that the 20-cent piece was a
similar size to the halfpennies, the position and its density fit into the sequence of
densities formed by the halfpennies. However, the penny had a slightly larger diameter
than both the halfpennies and the 20-cent piece but did not fit into the density pattern.
With only three halfpennies within the three areas under investigation not much can be
said about the pattern. The limited number of coins as a whole could not allow any
positive insight into the positioning of specific artefact types.
This analysis would have been aided by the presence of another artefact type that could
be compared to the findings of the coins. As this was not be the case, this particular
investigation could not find any conclusive evidence within the Holdfast Bay material
that a pattern has formed within the areas E, F and G. This restricted examination can
only be used as a reference to further studies into artefact patterning from other sites
that have more material. The consideration of the coins in this manner does highlight a
more effective way to explore the potential for patterning from within archaeological
trenches.
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8. Discussion
The aim of this thesis was to present the findings and resulting theories proposed by
researches who have studied artefact movement and patterning in archaeological
deposits.
With these theories were then test against the Holdfast Bay collection
excavated earlier this year. The investigations were solely based on those hypotheses
formulated by Keller (1972) and Moeyersons and Cahen (1977). Through this, a greater
understanding of artefact movement and patterning was generated.
This chapter
discusses the findings of the analysis of the Holdfast Bay assemblage, and concludes by
placing the data in relation to future projects.
Before any investigation into artefact movement could begin, it had to be determined
whether the archaeological deposits at Holdfast Bay were in chronological order. If
they were then there was no reason for an inquiry into artefact movement and
patterning. Ordering on this site was determined by the analysis of coins located in
areas E, F and G.
The coins indicated that these deposits had been disturbed.
Highlighting this point was the position of a 1974 20-cent piece below a 192?
halfpenny. There was no feasible way that the 1974 coin could have been deposited
before the halfpenny.
The 192? coin was an imperial coin, which were last in
circulation in June 1966, meaning that there was at east eight years before the 1974 coin
was minted and deposited on the site. The only solution to this was that the 1974 coin,
after being deposited, has moved below the 192? Coin.
Other diagnostic material was also used to support the mixing of the deposit. There
were four datable fragments of stubby bottle. These bottles were first introduced to
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South Australia in 1954 (Reed 1977, p.32). Some of the fragments dated from 1969 and
1975. The locations of these fragments were well into the deposits, and in some cases
were on the same level or underneath the imperial coins. There are no explanations for
the patterning of artefacts in this way, other than that the deposit had been disturbed.
Incorporating the research of oceanographers and other professionals in coastal
morphology supported the conclusion that the marine environment had disturbed the
sediment deposits, and therefore, the archaeological material within it.
Research
indicated that any of the four primary marine environmental forces; tides, waves,
currents, and wind, could effect sediment deposits. The presence or absence, as well as
the strength, determine how frequently the sediment can be disturbed. This is because
every coastal site is different, and as a result the specific environment at Holdfast Bay
needed to be investigated.
Research by Steedman (1974, p.128), Waters (1982, p.117) and Tronson (1973, p.94)
indicated that tides, currents and waves were more influential on sediment movement
when the strong south westerly winds were blowing in the Gulf St Vincent. The tide's
ability to create turbulence along the seabed is enhanced when the southwesterly wind is
blowing. The same was also said about currents operating in the gulf. The wind's effect
on the waves was such that it increased the strength and height of the waves (Kinsman
1965, p.17; Komar 1983a, p.1; Davis 1985, p.408). The stronger the waves, the more
influential they are in affecting the currents. The stronger the waves are, the more
sediment that they effect and transport (Tronson 1973, p.94; Waters 1982, p.30).
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The southwesterly winds are dominant for nine months of the year. This wind increases
sediment movement. This suggested that sediment deposits, theoretically, have only
three months of the year where they can settle and consolidate when the southwesterly
was not blowing. This may play a part in whether or not any pattern could actually
form in this environment.
By confirming that the deposits at Holdfast Bay were not in chronological order, the
investigations into the potential of artefact patterning continue. These investigations
were based on the work of Keller (1972) in the Norwegian harbours, Moeyersons and
Cahen's (1977) experiments, along with the excavation and field experiment conducted
by Stockton (1973).
Analysing the density of the artefacts in relation to their position was the first
investigation.
The first hypothesis posed by Keller was that artefacts within
unconsolidated sediments might settle according to how heavy they were (Keller 1972,
p.187). Such a pattern would need to show lighter artefacts were positioned at the top
of the deposit while heavier ones would be at the bottom. The analysis of artefacts from
areas E, F and G did not reveal any such pattern. While there were concentrations of
artefacts at certain depths within the deposits, these patterns were questionable, but
more importantly they were not representative of the site as a whole.
An example of these concentrations was trench F2. Artefacts could be seen to be
concentrated at three levels. The deeper the concentrations were, the more defined the
difference between the heaviest and lightest artefacts became. In the first section,
situated at the top of the deposit, the difference was 3.96g/cm3. The second section had
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a difference of 2.42g/cm3, while in the third section, the deepest, had a difference of
only 1.50g/cm3.
There were some restrictions in the visibility of this pattern. Firstly, this is the only
trench to show this patterning. Secondly, many density values were considered outliers,
this was due to the fact that they were extremely high in relation to the majority of
artefacts in the deposit. While these could be justifiably removed from the analysis, it
was only when these artefact were removed that a pattern formed. Thirdly, there were
no density values within the defined sections of the deposit that were unique to them.
That is, the artefact density values present in the third, more defined, section of the
deposits were equal to those at other depths in the deposit.
An explanation why different density values were present together could be due to the
influence of the environment. From analysing how often the marine environment had
the ability to disturb the Holdfast Bay deposits, along with the location of the artefact
concentrations, an idea of how far this effect could penetrate the deposit could be
determined. The affected area would be characterised by sediment that could not
consolidate. This would mean that the sediment would constantly be mixed, including
any objects within this area. If the shifting and mixing of sediments were occurring
frequently enough, then the objects incorporated in this layer would also move around
and not settle. This would account for the presence of artefacts with varying density
values. In addition, other artefacts within the lower, undisturbed, section of the deposit
may be able to form a pattern.
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Examining all of the trenches excavated in areas E, F and G revealed that four of the
seven trenches had concentrations of artefacts between the depths of 30 and 40cm. In
both E1 and G2, the larger of the two concentrations were at 40cm (Fig 5.2 & 5.8).
Trenches E2 and F2 also had similar concentrations of artefacts. However, within these
two trenches were also groupings of artefacts at 60cm (Fig 5.3 & 5.5).
G2 also
contained a grouping of artefacts at a depth of 20cm into the deposit.
While there seemed to be concentrations of artefacts at 40cm, this was not the case for
the majority of trenches.
Within these concentrations, thought to be where the
environment had less of an influence, artefacts stilled varied in densities. For example,
density values at a depth of 60cm in trench E2 included artefacts with densities of
2.00g/cm3, 3.25g/cm3 and 8.25g/cm3 (Fig 5.3).
In trench F3 there were artefacts
concentrated at a depth of 30cm below the seabed ranging from 0.50g/cm3 to 4.41g/cm3
(Fig 5.6).
As there were a variety of depths where these concentrations occurred, the level to
which the environment was influencing the deposit could not be determined. Also, no
pattern was visible in the lower sections of the deposit, where concentrations of artefacts
collected. This was highlighted by the assortment of artefact density values present.
The results so far have not shown any clear evidence that the position the artefacts was
determined by their density. While there was a pattern forming in F2, this was the only
trench to show any signs that a pattern might exist.
The second investigation examined the position of the artefacts in relation to their
material type. This was another hypothesis proposed by Keller (1972), but also by
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Moeyersons and Cahen (1977) and Stockton (1973). This investigation was based on
the principle that objects that were made from one specific material, such as green glass
as apposed to iron, may be located in groupings together. This may help explain why
there were large concentrations of artefacts gathered at one level.
There were eight material types in the Holdfast Bay assemblage. There were only five
types, however, that occurred frequently enough to conduct this investigation. These
material types were green, brown and clear glass, and objects made from lead and
alloys.
From this examination of the concentrations appearing within each trench, there was no
one material type that stood out as the cause. The objects represented at a depth of 40 to
50cm in trench G1, for example, were made from alloys (6), green (5) and brown (4)
glasses, as well as single pieces of ceramic and blue glass. It could be said, therefore,
that the concentrations were not made of one particular material type. This is only one
example of what was exhibited in all the trenches.
The third examination was to investigate the position of artefacts in relation to their
individual material types.
That is, all green glass fragments were analysed and
compared to the location of all other green glass fragments, and so on. From this study
a pattern was seen in the position of the brown glass fragments. There were 37 brown
bottle glass fragments uncovered from areas E, F and G. Of these, 27 were found
between the depths of 30 and 40cm. Five of the remaining 10 fragment were above this
group while the other five were below. In total, 86.5 per cent of these brown glass
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fragments were located below 30cm, but 73 per cent of the fragments were actually
between 30 and 40cm.
The positioning of the brown glass may indicate a pattern. Why specifically the brown
glass was settling in this manner is not known, as again this was the only material type
to demonstrate any patterning. Clear and green glass fragments were found at various
levels within all deposits. The same lack of patterning was seen with the position of the
alloy and lead objects. With only one particular material type showing positive signs of
patterning within the deposit, no claim can be made.
The third and final investigation carried out on the Holdfast Bay assemblage was the
position and density of specific items. In this case coins were used. Coins were chosen
because of their standardisation. Eight coins were uncovered in areas E, F and G. For
this investigation the two heavily deteriorated coins were not included. This was as
they were only inferred as coins from their dimensions. From the position of the coins
and their densities in relation to one another there was no pattern as there was a large
variation of densities at different depth.
A further analysis of these coins compared the position of the halfpennies. This could
only be conducted on halfpennies as there were no other coins represented by more than
one. The three halfpennies were at depths of 10, 30 and 60cm below the seabed. The
densities related to the coins were 8.15g/cm3, 8.84g/cm3 and 10.19g/cm3 respectively.
This sequential ordering of the coins suggested that they might have formed into a
pattern.
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This ordering, however, is based only on three artefacts, which limits its validity. There
were no other items present in the Holdfast Bay assemblage to compare these findings.
Once again the presence of a possible pattern was seen, but further research is needed
from another study to confirm these findings.
From the three primary investigations there have been limited evidence of patterning.
In all cases, however, there was no other data to back it up. From the study of the
specific environment around Holdfast Bay, a hypothesis can be suggested as to why
there are limited patterns. The research indicated that the marine environment was
strong enough for nine months of the year to influence the sediment deposits. This
suggested that the site had approximately three months a year to consolidate. Any
patterning of the artefacts would theoretically only be able to form in these three months
before the strong south-westerlies again dominated the area, disturbing the deposit.
This would mean that the environment at Holdfast Bay could be a middle environment.
In this middle environment, artefacts within the deposits do have the potential to form
patterns according to some of their attributes. However, the environment in the area
would also be strong enough, at certain time of the year, to dissolve them.
If this was the case, the environmental factors at Holdfast Bay, which are known, could
be used to find a site more promising to investigate artefact patterning.
Thereby
choosing a site where the potential for patterning within the sediment may occur.
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Potential for further research.
While the Holdfast Bay investigation did not find evidence for or against the
proposition of artefact movement and sorting, it has, however, flagged some
possibilities. From presenting and testing the previous findings the potential of this type
of research was recognised, and suggestions for the future can made.
This thesis has proposed that the environmental influences on a site affect the vertical
movement and positioning of artefacts within a shallow marine deposit.
research is necessary to define these influences.
Further
It is recommended that future
excavations investigate variety of different environmental areas to further understand its
affect.
This thesis included only three examinations.
Broadening the scope of future
investigations to include other factors enhances the possibility of recognising attributes
that may cause patterning, if patterns do indeed exist. Such attributes could include the
size or total surface area of the artefact. The size or surface area may affect an artefact's
ability to move through sediments.
A logical way of conducting further research in an attempt to understand the influence
of the environment and study artefact movement within the deposits would be to
conduct a controlled experiment. This would optimise the potential of the study. The
use of predetermined artefacts controls their attributes. For example, testing whether
the surface area of an artefact was a factor, two different types of coins could be used,
for example 10 cent pieces against 50-cent pieces.
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Selecting an area where the conditions were similar to Holdfast Bay, in wind and depth
of water over the site would allow additional information to be collected regarding
artefact movement in that particular environment. Conversely, choosing a site(s) where
the environment was different, would create a comparative sample of noteworthy
interest.
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9. Conclusion
The Holdfast Bay excavation, assemblage and analysis has concluded that artefacts in
shallow marine deposits have the potential to be influenced by the environmental
factors, to the extent that the location of the artefacts within the deposits were disturbed.
Creating the situation where the deposits are no longer in any form of chronological
order. As it was confirmed that the site had been disturbed, the analysis brought
forward the limited work previously carried out into artefact patterning.
While there has not been a great deal of research into artefact movement and patterning
in the marine archaeological record, this preliminary investigation based on the Holdfast
Bay data has highlighted the potential for research into the topic. From focusing only
on the work of Keller, Moeyersons and Cahen, and also from Stockton, the structure of
the analyses was formed. However, adding to it research by archaeologists into the
environmental effects on shipwreck sites, as well as research from oceanographers
themselves on the operations of the environment, guided the findings of this thesis to
consider and raise other possibilities of the positioning of objects in these deposits.
While it is stressed that further research is needed before any of the outcomes proposed
in this thesis can be supported, future investigations may take into consideration the
measures taken in this thesis in determining whether patterns exist in the archaeological
environment. This thesis has, however, provided a benchmark for future research.
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