Accessory minerals and δ18 O and δ13 C of marbles from the

Transcription

Journal of Cultural Heritage 5 (2004) 27–47
www.elsevier.com/locate/culher
Original article
Accessory minerals and d18O and d13C of marbles
from the Mediterranean area
Silvio Capedri a,*, Giampiero Venturelli b, Adonis Photiades c
a
Dipartimento di Scienze della Terra, Università di Modena e Reggio Emilia, largo S. Eufemia 19, 41100 Modena, Italy
b
Dipartimento di Scienze della Terra, Università di Parma, Parco Area delle Scienze 157/A, 43100 Parma, Italy
c
Institute of Geology and Mineral Exploration, Messoghion Str. 70, 11527 Athens, Greece
Received 12 February 2003; accepted 24 March 2003
Abstract
Seventy-five samples of marbles from Italy, Greece, Turkey and FormerYugoslavia Republic of Macedonia (F.Y.R.O.M.) were investigated
for the accessory minerals, never treated systematically before, and were studied also petrographically and analysed for C and O isotopes. The
accessory minerals, investigated by scanning electron microscopy and analysed quantitatively by energy dispersive spectrometry, include:
quartz, plagioclase, apatite, sulphides and oxides, different types of micas (muscovite, phlogopite, aspidolite, paragonite, margarite), chlorite,
kaolinite, pyrophyllite, montmorillonite, epidote, amphibole, organic substance. The distribution of these minerals is not uniform among the
marbles investigated and has considerable implications on the discrimination of marble localities, and hence on the provenancing of
archaeological marbles.
© 2004 Elsevier SAS. All rights reserved.
Keywords: Mediterranean marbles; Italy; Greece; Turkey; F.Y.R.O.M.; Accessory minerals; Localities discrimination; Archaeological marbles; Provenance
1. Introduction
Amongst the most aesthetically valuable stones used in
antiquity and in recent times for relevant architecture and
decorative work, marbles played an outstanding role, particularly under the Romans. Blocks of marble were transported
far from quarries and spread over the Mediterranean archaeological sites.
Many papers have been devoted to the characterisation of
marbles in general, and of white marbles in particular, of
important ancient quarries, using mainly petrographic and
geochemical parameters (see for example [1–15]), but also
other techniques including cathodoluminescence [16,17],
electron spin resonance (ESR) [18], light diffusion [19].
Admitting the subtle differences (petrographic, mineralogical and chemical) among the marbles (especially the white
marbles), the discrimination of stones of the various sources
as well as the provenancing of archaeological marbles is not
always univocal, however; when applied separately, none of
the suggested parameters can discriminate unambiguously
the marbles of the various sources.
* Corresponding author.
E-mail address: [email protected] (S. Capedri).
© 2004 Elsevier SAS. All rights reserved.
doi:10.1016/j.culher.2003.03.003
One aspect, still scarcely investigated, concerns the mineral accessories of marbles. This paper is aimed (1) to the
typological characterisation of the accessories of marbles
(mainly white marbles) coming from different Mediterranean areas, including those of important localities exploited
in the past, (2) to evaluate the accessories as potential parameters in the discrimination of the marble sources, and (3) to
report new oxygen and carbon isotope data.
2. Marble localities analysed
The 75 marbles come from the Mediterranean area and
comprise the most important typologies used in antiquity.
More precisely they come from Italy (one locality: Carrara,
Fig. 1), Greece and Former Yugoslavia Republic of Macedonia (F.Y.R.O.M.) (21 and 1 locality, respectively, Fig. 2),
and from Turkey (nine localities, Fig. 3).
2.1. Techniques applied
Marble samples were thin sectioned for petrographic examination. Since most samples of marbles investigated are
28
S. Capedri et al. / Journal of Cultural Heritage 5 (2004) 27–47
ticular reference to calcite and dolomite, as well as to detect
the accessory grains, which were not seen under the microscope, because they were too small.
The oxygen and carbon isotope ratios are referred to the
standard VDPB (Belemnitella americana from the Cretaceous Pee Dee Formation, South Carolina) and expressed as:
d O (‰) = 10 [( O⁄ O)sample −
18
3
18
16
18
16
18
13
12
13
16
( O⁄ O)VPDB] ⁄ ( O⁄ O)VPDB
and
d C (‰) = 10 [( C⁄ C)sample −
13
3
13
12
12
( C⁄ C)VPDB] ⁄ ( C⁄ C)VPDB .
Isotope determinations were performed at the Stable Isotope Laboratory, Earth Sciences Department, University of
California, Santa Cruz, and at the Geologisches Institut,
ETH-Zentrum, Zürich.
2.2. Petrographic features and isotope composition
of the analysed marbles
Fig. 1. Location of Carrara quarries.
internally very homogeneous and the accessories are randomly distributed, it is probable that grains of the different
kinds of accessory minerals present are met by the thin
section. To test this, more thin sections were cut to variable
orientation from few selected samples and processed by
scanning electron microscopy (SEM)–energy dispersive
spectrometry (EDS) for mineral accessories; the reproducibility of data was internally rather consistent. Therefore,
only one thin section was investigated for each sample and
the results were considered as qualitatively representative for
that sample. The foliated marbles, which frequently concentrate the accessories in the foliation plane, were sectioned
perpendicular to foliation.
Most samples analysed are from the classical marble
sources of antiquity, e.g. Carrara, Penteli, Paros, Naxos,
Thasos, Marmara, Afyon (Dokimion), Aydin (Aphrodisias),
very few from other less important localities (e.g. the
samples from most Cyclades islands). The obtained data may
be taken as preliminary to the knowledge of the accessory
mineralogy of marble sources, particularly where only few
samples were treated. To achieve a comprehensive picture of
the accessory mineralogy a detailed field survey, followed by
accurate sampling and processing of the various lithologies,
should be performed at each site.
All grains recognised under the microscope were marked
onto the thin sections for later processing by electron microscope. A SEM (model Jeol 6400), equipped with EDS (ISIS
300 model, calibrated using natural standards), was used at
the Dipartimento di Scienze della Terra, University of Parma.
SEM imaging was employed both to evidence the geometrical relationships among the mineral constituents, with par-
The analysed marbles are texturally very variable (terminology according to Heinrich [20], unless otherwise specified):
• Homeoblastic marbles, which are made of equidimensional grains.
• Heteroblastic marbles, formed by grains of different
size.
Both groups of marbles are made of anhedral crystals
(xenoblastic grains, mostly carbonates) and may contain
euhedral (idioblastic) grains made mostly of non-carbonate
accessories (e.g. plagioclase, micas, opaques, etc). Marbles
of both groups may be:
• Granoblastic, if the xenoblastic grains of carbonates
have straight to curved borders; this texture is also
known as “polygonal mosaic” or “foam” (Hibbard [21]),
and as “crystalloblastic” (Best [22]). Or
• sutured, when the grains are highly interlocking as in a
jigsaw puzzle.
Granoblastic and sutured marbles may be either:
• isotropic (having similar aspect in any direction) or
• anisotropic (non-random or directional) (Best [22]), depending upon the forces acting on the rock body undergoing recrystallisation; isotropic marbles are related to
rather passive environments, whereas anisotropic
marbles were generated under tectonic forces, which
controlled the spatial growth and orientation of minerals, and led to lineated and foliated lithologies.
• Marbles whose crystals are granulated along their borders and, in thin section, are found to be contoured by a
fine-grained matrix, show mortar texture (Jung [23]).
• Marbles, which underwent stronger mechanical deformation, and are characterised by angular fragments of
former marble (marble protolith) or of former carbonate
29
Fig. 2. Location of marbles analysed from Greece and F.Y.R.O.M.
grains, commonly bent and strained, set into a matrix,
normally subordinate, made of smaller pieces of carbonates, develop cataclastic texture.
Some of the marbles analysed here, too fine-grained for
the detection of the intergranular geometries under the microscope, were texturally defined simply as “microgranular”. Some marbles, showing the textures mentioned above,
were fractured in turn and cemented by late veins mainly
carbonatic; those marbles are referred to as “brecciated”.
The maximum grain size of calcite (MGS)—which has
been used to discriminate the marbles (e.g. [7])—was measured. The geometric relationships of carbonate grains (the
grain boundary shape, GBS) were also evaluated under the
microscope.
These features depend on the metamorphic evolution. In
well recrystallised marbles, the stable grain boundary configuration is evidenced by plane contact surfaces of adjacent
polyhedral grains of carbonates and by triple-grain junctions
meeting at about 120° angles. The textural features (illustrated in Figs. 4 and 5), GBS, MGS, besides a general de-
scription of the analysed marbles are depicted in Table 1,
which reports also O and C isotopes composition for the
majority of samples investigated. The isotopic composition is
illustrated in Fig. 6 (samples from Italy, Greece and
F.Y.R.O.M.) and Fig. 7 (samples from Turkey). Samples
from classical areas plot into the expected isotopic reference
fields. In particular: the Parian samples plot into field Pa-1
(Fig. 6) defined by the lychnites variety; three Thassian
marbles plot into field T-3 (Fig. 6) defined by marbles from
Vathy-Saliara district, and one (sample TH3 from Aliki) plots
at the intersection of fields T-1 and T-2, the last one being
defined by the marbles from Aliki district; the Proconnesian
samples plot into field Pr-1 (Fig. 7) defined by main variety
of marbles from Marmara. C and O isotopic determinations
of marbles from other localities, provide first data, or integrate isotopic information reported in the literature for those
sites. The data here reported show wide variations among the
samples from same locality (e.g. Tranovaltos, Ikaria island
and Sikinos island in Greece, and Latmos in Turkey),
whereas they are almost constant in other localities (e.g.
Fig. 3. Location of marbles from Turkey.
30
Eliconas in Greece, and Mugla/Salkim in Turkey). The acquired data suggest that the marbles from Crete (Talea Ori
and Mires) are isotopically different. The large overlapping
of the analysed samples is outstanding, and makes d18O and
d13C alone not always effective in discriminating the marble
source.
3. The accessory minerals of marbles
3.1. General considerations
Marbles were derived from the metamorphic recrystallisation of carbonate-dominant protoliths (mainly limestones,
magnesian or dolomitic limestones) containing also minor
silicate minerals. Granting that the protolith was pure carbonate (CaO, MgO, CO2 chemical components), the derived
marble (pure marble) will be composed of carbonates only,
mainly calcite (from pure limestones) and dolomite (from
dolostones) or by a combination of the two carbonates, depending on the Ca/Mg ratio of protolithic (magnesian or
dolomitic) limestone. More frequently, however, in addition
to CaO, MgO, and CO2, the protoliths contain other chemical
components (e.g. SiO2, Al2O3, FeO, Fe2O3, Na2O, K2O),
which even at low concentration, influence the mineralogy of
the derived marbles. Marbles with accessory proportion of
non-carbonate minerals are white, whereas marbles rich in
those phases may be variously coloured, depending on the
type and proportions of minerals present. For example, the
Carystian marble from Euboea, also known as “cipollino
verde”, is green in colour, the “pavonazzetto” marble from
Afyon is wine-red, and the Bardiglio variety of Carrara
marble is greyish-veined, because they contain Fe-bearing
accessories (chlorite and epidote) [10], hematite [26], and
carbon derived from biological material, respectively.
Non-carbonate minerals have been reported in the literature for most kinds of marbles, where they were identified
mainly by optical microscope [10,27–31], and occasionally
by X-ray diffractometry (e.g. [32,33]). Optical microscope
enables the identification of most common minerals, granted
that the grains are big enough for proper evaluation of the
diagnostic characteristics. However, the accessories of most
marbles exploited in the past are frequently too small and rare
(only very few grains may occur in one thin section) to allow
safe optical identification. Some accessories may be attributed optically to mineral groups rather than to specific typologies: for example, the flakes of white mica were defined
generically as “mica” mineral, whereas both oxides and
sulphides were referred to as “opaques”. These and similar
uncertainties may be overcome by electron microscope; in
addition, since it operates up to very high magnification
(practically up to 104×, by contrast with a common optical
microscope which operates up to 400–500× maximum), the
grains that are too small to be seen under optical microscope
can be detected and analysed, and hence the full list of
accessories present in one thin section compiled.
31
3.2. The accessory minerals of the investigated marbles
The analytical quality of the SEM–EDS analyses may be
evaluated from Table 2 where the replicate determinations of
selected grains of minerals were performed by a more accurate and precise method (ARL-SEMQ microprobe) at the
University of Modena and Reggio Emilia. Comparing the
analytical results, SEM–EDS was preferred mainly because
of its high quality back-scattered imaging and smaller electron spot, which allows safe and easy detection of the accessory minerals even in grains of very small size. Minerals,
large enough to avoid excitation of surrounding carbonate
matrix from the electronic beam, were analysed quantitatively and the results are reported in Tables 3–5. Grains too
small to avoid excitation of carbonate matrix, were analysed
qualitatively and their identification inferred resolving the
combined spectra. The shape and geometric features of
grains were also used both for identification (for example it
may help to discriminate minerals which are indistinguishable chemically through the EDS spectrum, but have different structure and habit, e.g. pyrite and marcasite, hematite
and magnetite, rutile and anatase, etc.) as well as to evidence
aspects which may be peculiar and thus diagnostic for enclosing marbles (e.g. transformation relationships or simultaneous crystallisation under equilibrium conditions). The
accessories are reported in Table 6; their morphological and
chemical features, shown in the different marbles, are outlined in the description below.
3.2.1. Silica phases
The commonest silica phase is quartz which occurs, generally, as few grains (e.g. at Eliconas, Afyon and Aydin); in
some marbles, however, e.g. from Boana Arnetola and Colonnata, Carrara district, Penteli, Mugla/Golkuc (Iasos) (“cipollino rosso” variety, actually a calc-silicate rock), it is
relatively abundant. Quartz grains are generally below
200 µm in size, in places up to 0.5 mm (e.g. at Carrara,
Penteli-sample
G9,
Sikinos-sample
SK24
and
Mugla/Golkuc-red variety). Quartz varies in shape from euhedral (at Folegandros and Samos), to variously anhedral
(e.g. at Talea Ori: corroded and substituted by carbonates;
Mani: discoidal and lying in the foliation plane). In the
minutely cataclastic grey marble of Iasos, quartz cements the
fragmented calcite and grew lobed; at Sikinos (sample
SK24), Carrara and Penteli the grains are rounded and probably detrital. At Penteli the detrital origin of quartz (possibly
from metamorphic protoliths) may explain the undulatory
extinction frequently shown by quartz grains. Occasionally
silica is microcrystalline (chalcedony): chalcedony fills late
microfractures of marble from Ikaria, whereas mammillary
banded chalcedony, filling small cavities, has been observed
at Teos.
3.2.2. Plagioclase
Plagioclase, rare among the marbles analysed, is mostly
euhedral pure albite (Table 3), twinned in the albite law. It
32
shows blade contact with the enclosing carbonates, suggesting simultaneous crystallisation, at Carrara (crystals 0.1–
0.2 mm across), whereas at Mani, the plagioclase grains (up
to 200 µm in diameter) are dentate towards the host; furthermore plagioclase of Mani is undeformed, by contrast with the
host carbonates which are strained, implying late crystallisation of plagioclase. At Aydin and Mugla/Golkuk plagioclase
is again albite, but not so extreme in composition as in
previous localities (Table 3). At Aydin plagioclase is exceptional as euhedra twinned in the albite law, either with two
lamellae only or with multiple lamellae (polysynthetically
twinned). Plagioclase in the red marble from Mugla/Golkuk
occurs as frequent grains of variable size (up to 0.4 mm),
mostly anhedral.
3.2.3. Apatite
It is the commonest accessory mineral among the studied
marbles. The grains are mostly very small (generally <40
µm) (e.g. at Carrara, Penteli, Paros, Marmara and Aydin), but
up to 100 µm in places (e.g. at Naxos, Thasos, and at
Balikesir/Kocoglu); generally they grew euhedral during
metamorphic recrystallisation, but also anhedral grains,
rounded in shape and probably retaining detrital morphology, are seen in places (e.g. at Penteli “B”, Thasos,
Mugla/Salkim). The crystals are generally scattered, but in
some marbles (e.g. at Penteli, and in the grey marble variety
of Mugla/Golkuk) the crystals cluster in aggregates; at
Mugla/Golkuk the interspaces of the grains forming the aggregates are typically filled with graphite.
3.2.4. Sulphides and oxides/hydroxides
Occur mostly in some coloured (particularly redcoloured) marbles, like the red marble (“cipollino rosso”)
from Mugla/Golkuk, the red marble from Afyon (“pavonazzetto” variety), and the greyish marbles from Mugla/Salkim
(locality not far from Iasos). Otherwise they are extremely
rare. The grain size is generally very small (mostly <30 µm,
frequently close to 5 µm), but may be distinctly bigger (up to
0.7 mm) in some Turkish marbles from Mugla district and
from Latmos.
Sulphides are mostly Fe-sulphides; exceptionally Znsulphides and Cu–As–V-sulphides have been detected at
Thasos and Carrara, respectively. Zn-sulphide mantles Fesulphide at Thasos. The grains may be internally homogeneous (e.g. at Carrara, Mani, Afyon, Mugla/Salkim, Marmara, Latmos, Aydin and Mugla/Golkuk), or sieved (e.g. at
Penteli).
33
Oxides are mostly Fe-oxides, which, in places, have been
identified morphologically as hematite; however, other types
of oxides have been detected, including Ti-oxides (probably
rutile, as suggested by crystal shape) (e.g. at Carrara, Penteli,
Eliconas, Naxos, Marmara), Fe–Ti-oxides (at Samos and
Iraklia), besides Mn- and Cr-oxides (evidenced only at Penteli). Locally (e.g. at Naxos, Tinos, and Mugla/Salkim) Feoxides are mantled by Si-enriched secondary Fe-hydroxides.
Fe-oxides (hematite) are concentrated particularly in marbles
coloured in shades of red; in these marbles, particularly the
red-coloured marble from Afyon (sample PAV: “pavonazzetto”), from Mani (sample PA3: “rosso antico”) and from
Mugla/Golkuk (sample G16: “cipollino rosso”), hematite
occurs as very small scattered grains (generally <25 µm),
and/or concentrated as veinlets, which induces the staining
effect.
3.2.5. Fluorite
Fluorite has been detected only in marbles from Turkey,
particularly from Mugla/Salkim, where it is abundant, and
from Marmara and Balikesir/Kocoglu, where it is rather
frequent; the crystals, occurring both in calcite and dolomite,
reach 100 µm in size.
3.2.6. Zircon
Two small grains detected at Volakas.
3.2.7. Epidotes
Epidotes have been detected sporadically only at three
localities (Table 4). At Tranovaltos the iron-rich variety (epidote s.s) is very abundant, whereas rare crystals of zoisite
(110 µm) occur at Naxos. Epidote is also abundant in the red
marble from Mugla/Golkuc, generally as chemically homogeneous grains; occasionally, however, epidote mantles
rounded allanite (rare earth-rich epidote) grains (probably
clasts).
3.2.8. Amphibole
Amphibole (tremolite) (Table 4) has been found only in
the red marble of Iasos, where it occurs as slender colourless
euhedral prisms reaching 2.3 mm in length.
3.2.9. Chlorite
Chlorite has been detected sporadically; by contrast it was
found in all samples analysed from Mugla/Salkim. In places,
it is in the form of individual crystals set in carbonates (e.g.
Carrara, Prilep), or in bundles (e.g. Penteli); in other marbles
Fig. 4. Microphotographs showing textural features of selected marbles. (A) homeoblastic, granoblastic, isotropic; plain contacts of calcite grains meeting at
equiangular triple points (sample G19 from Prilep, F.Y.R.O.M.) (long side length 2.7 mm). (B) Homeoblastic, granoblastic, isotropic marble showing lobate
contacts of calcite grains (sample G24 from Mugla/Salkim, Turkey) (long side length 2.7 mm). (C) Homeoblastic, isotropic marble (sample G15 from Thasos)
showing sutured grain boundaries of dolomite (long side length 2.7 mm). (D) Heteroblastic, isotropic marble showing lobate contacts of calcite grains and
inequiangular triple junctions (sample G11 from Naxos; long side length 5.7 mm). (E) Heteroblastic sutured marble (sample 179 from Dokimion, Turkey; long
side length 2.7 mm). (F) Heteroblastic marble, with dentate grain boundaries (sample 138 from Larissa, Greece; long side length 5.7 mm). (G) Marble
characterised by lobate contacts of calcite grains meeting at inequiangular triple junctions (sample G28 from Balikesir/Kocoglu, Turkey; long side length
2.7 mm). (H) Heteroblastic marble showing equilibrium texture in the coarse-grained portion (sample 180 from Teos, Turkey) (long side length 2.7 mm).
Microphotographs taken under crossed nicols.
34
chlorite is intergrown with other phases, suggesting simultaneous crystallisation: for example chlorite lamellae alternate
with phlogopite at Naxos and Mugla/Salkim, with phlogopite and phengitic muscovite at Iasos, and with graphite at
Thasos. Chemically the analysed chlorite belongs to Mg-rich
types (Table 5), with variable concentration of iron. For
example at Naxos, Thasos, Penteli, Prilep, Tranovaltos, and
Mani chlorite has the composition of pure Mg-end member,
whereas in the other localities chlorite is mildly ferriferous,
with lower Fe concentration at Mugla/Salkim and
Mugla/Golkuc and higher concentration at Carrara.
3.2.10. Kaolinite
Kaolinite occurs sporadically at Naxos, Volakas, Marmara, Afyon and Aydin (Table 5). It forms very small crystals, either discrete or finely intergrown with phlogopite
(Marmara), and pyrophyllite (Afyon), or as minute radiating
aggregates (Volakas).
3.2.11. Pyrophyllite
Pyrophyllite occurs only at Afyon (Table 5) in the red
marble variety.
3.2.12. Montmorillonite
Montmorillonite occurs only in one sample from Aydin
(Table 5), as very small crystal aggregates filling one small
cavity in association with albite.
3.2.13. Graphite
Graphite is quite frequent, relatively abundant in some
greyish to black marbles, where it may concentrate in layers;
it is rare in white marbles, where it is dispersed uniformly and
in places has grown interstitially between the carbonates.
3.2.14. Micas
White mica is relatively frequent, although not ubiquitous
(Table 4). It has not been detected in a number of localities,
comprising Eliconas, Agia Marina, Larissa, Veria, Volakas,
Mires, Talea Ori, Folegandros, Keros, Tinos, Ikaria,
Balikesir/Manyas and Teos. In some localities, e.g. Carrara,
Afyon and Mugla/Salkim, mica is sporadic, in other localities, e.g. at Penteli, Thasos, Tranovaltos and Marmara, it is
common. Mica occurs as tiny flakes (e.g. at Carrara, Aydin,
Paros, Iraklia, and Sikinos) or as bigger crystals (up to
1.4 mm) (e.g. at Penteli, Naxos, Thasos, Balikesir/Kocoglu,
and Afyon). The crystals are euhedral, in general, and unde-
35
formed; in some marbles they are oriented randomly (see for
example: Carrara, Aydin, Paros, and Thasos), whereas in a
number of other localities they show sub-parallel spatial
orientation, marking the metamorphic foliation of host rock,
e.g. at Penteli, Tranovaltos, Sikinos, Volakas, and occasionally at Naxos and Afyon.
Where mica coexists with low-temperature phyllosilicates
(chlorite, kaolinite, and pyrophyllite), composite crystals occur, which are made of mica lamellae (frequently phlogopite)
alternating regularly, through blade contacts, with the above
mentioned phyllosilicates. The geometric arrangement does
not suggest an alteration relationship between mica and the
low-temperature phyllosilicates, but better may be related to
simultaneous crystallisation of the phases. If so, it may be
inferred that marbles (e.g. Penteli, Naxos, Prilep, Thasos,
Mugla/Salkim, and Marmara), containing low-temperature
phyllosilicates, crystallised under quite low metamorphic
grade.
Different types of white mica were detected: muscovite
{KAl2AlSi3O10(OH)2}, phlogopite {KMg3AlSi3O10(OH)2},
paragonite {NaAl2AlSi3O10(OH)2}, margarite {CaAl2
Al2Si2O10(OH)2}, aspidolite {NaMg3AlSi3O10(OH)2}. The
analysed crystals have the composition of end-members
(Table 5); no significant miscibility has been observed even
among different micas coexisting in the same sample. In
particular mica does not contain Fe, which explains why all
micas analysed appear colourless under the microscope. The
consequence is that the typologies of micas can be recognised chemically. Mica types from different localities have
similar composition, with slight chemical variation shown by
phlogopite and muscovite. For example phlogopites from
Naxos and Paros contain less Si per formula unit (f.u.) in
respect to those from Thasos, and phlogopites from Marmara
show ranges in Na and K concentrations which are not seen at
Naxos, Paros and Thasos. Muscovite shows variation in the
Si/Al ratio. On the basis of Si per formula unit (f.u.), the
analysed muscovites have been assigned conventionally to
the following three groups: muscovite s.s. (Si < 3.1 f.u.);
phengitic muscovite (Si comprised between 3.1 and 3.4 f.u.);
strongly phengitic muscovite (Si > 3.4 f.u.) (Fig. 8). The
increase of Si in the tetrahedral sites is accompanied by the
substitution of Mg for Al in octahedral sites (Fig. 9) as
required by charge balance. Consequently the marbles may
be characterised by chemical characteristics of mica, such as
Si (f.u.), Al (f.u.), and Mg (f.u.) and the related localities
discriminated accordingly. In particular the Mg/Si ratio of
Fig. 5. Microphotographs showing textural features of selected marbles. (A) Marble slightly deformed showing grains of calcite crumbled to finer grains,
characteristic of mortar texture (sample G7 from Veria) (long side length 2.7 mm). (B) Marble slightly deformed as shown by calcite grains bent and glide
twinned (sample G26 from Balikesir/Manyas, Turkey). (C) Cataclastic marble showing fragmented and highly deformed calcite set into fine-grained carbonate
(sample 176 from Iasos) (long side length 0.9 mm). (D) Cataclastic marble showing discoidal relics of marble protolith set into fine-grained marble; secondary
foliation developed (sample 21 from Dokimion) (long side length 2.7 mm). (E) Foliated marble, with foliation plane defined by flattened calcite crystals (sample
93 from Aydin, Turkey) (long side length 5.7 mm). (F) Foliated marble, with foliation evidenced by mica flakes (sample G9 from Penteli) (long side length
2.7 mm). (G) Microgranular marble brecciated and cemented by coarse-grained calcite (sample KE15 from Keros) (long side length 2.7 mm). (H) Marble
composed of calcite and subordinate dolomite (turbid) (sample G22 from Mugla/Salkim, Turkey) (long side length 2.7 mm. Plane polarised light). Photographs
taken under crossed nicols, unless otherwise specified.
36
Table 1
Main petrographic features and isotope composition of analysed marbles from type-localities of the Mediterranean
d18O
(‰)
Sample
Texture
GBS
MGS
(mm)
Cal
Italy (Fig. 1)
Carrara-1
A13
Ho, G, I
St
1.3
Only
A24
Ho, G, I
St
0.6
Only
A21
Ho, G, I
St to Cr
0.5
Main
Rare
A25
Ho, G, I
Cr
0.7
Main
Rare
A3
Ho, G, I
St to Cr
0.8
Main
Rare
A7
Ho, G, I
St
0.8
Only
A5
Ho, G, I
St to Cr
0.7
Only
A37
Ho, G, I
St to Cr
0.8
Only
A36
Ho, G, I
St
0.5
Only
A31
Ho, G, I
St to Cr
0.4
Main
Rare
A6
Ho, G, I
Cr to St
0.3
Main
Rare
A12
Ho, G, I
St to Cr
0.3
Main
Rare
A16
C, He, S
<0.1
Only
A22
Ho, G, I
Cr to St
0.7
Only
A20
Ho, G, I
St to Cr
0.9
Main
Rare
MA1
Ho, S, F
D to Cr
0.5
Main
Rare
2.62
–1.98
G9
Ho, A, F,
S
Cr to D
1.0
Main
Sub.
1.84,
1.95
–6.06,
–6.10
Carrara-2
Carrara-3
Carrara-4
Carrara-5
Dol
d13C
(‰)
Locality
Petrographic notes
Fine-grained homogeneous calcite marble, showing
well developed equilibrium texture. Plagioclase
common
well developed equilibrium texture. Rare accessories
uniformly distributed throughout
Fine-grained homogeneous calcite marble containing rare turbid dolomite as thin layers and isolated
grains. Accessory minerals occur mostly in the dolomite fraction
Fine-grained homogeneous calcite marble containing turbid dolomite both as thin layers and isolated
grains. Rare Fe-sulphides present
Fine-grained homogeneous calcite marble containing rare turbid dolomite as thin layers and isolated
grains. Accessories related mostly to the dolomite
fraction
well developed equilibrium texture. Rare flakes of
white mica present
well developed equilibrium texture
well developed equilibrium texture
Fine-grained homogeneous marble composed of calcite grains showing equilibrium geometries. White
mica is the only rare accessory
Fine-grained homogeneous calcite marble containing rare turbid dolomite both as thin layers and
isolated grains
isolated grains. Accessories occur mostly in the dolomite fraction
isolated grains. Accessories very rare
Very fine-grained cataclastic marble. Accessories frequent crowding deformed thin layers
Fine-grained homogeneous marble composed of calcite grains showing geometric configuration close to
equilibrium
Fine-grained homogeneous calcite marble containing rare aggregates of turbid dolomite. Accessories
uniformly distributed
Fine-grained calcite marble containing rare turbid
dolomite; sutured texture distinctive. Accessories
uniformly distributed throughout
Greece (Fig. 2)
Penteli
Marble composed of alternating layers mainly of
limpid calcite and subordinately of turbid dolomite
(greyish macroscopically). The calcite crystals are
flattened parallel to the foliation plane defined by the
micas. Accessories occur mostly in dolomite, subordinately in calcite fraction
(continued on next page)
37
Table 1
(continued)
Locality
Sample
Texture
GBS
G12
Ho, A, F, S
G1
Sub.
d13C
(‰)
2.57
d18O
(‰)
–4.45
Main
Sub.
2.74
–7.34
Cal
Dol
Cr to D
MGS
(mm)
1.0
Main
W-He,
A, F, S
St to Cr
1.3
Eliconas 1
G20
G3
Ho, B
NE
<0.4
Acc.
Main
2.73
2.67
–6.13
–3.32
Eliconas 2
G4
C, He, F
S
Var.
Sub.
Main
2.52
–3.82
Agia Marina
AM
C, He, F
NE
Main
Rare
2.41
–0.97
Aliveri
136
C, He, F, S
3.0
Main
Rare
Mani (P. Elias)
PA3
Ho, F, A,
S
Cr to D
0.3
Only
1.60
–0.28
Mani (Diros)
134
C, He, S
Cr to D
5.0
Only
4.02
0.26
Larissa
137
W-He, S, I
Cr to D
2.0
Only
2.01
–2.77
138
He, S, I
Cr to D
4.6
Only
1.65
–1.77
TR1
Ho, G,
A, F
St to Cr
0.4–1.0 Only
0.57,
1.01
–5.75,
–5.70
TR2
Ho, G, I
St
0.6
Only
4.13
–2.72
TR3
Ho, G,
W-F,
W-A
St
0.5
Main
Sub.
2.75
–2.91
TR5
Ho, G, I
St
0.5
Main
Rare
3.57
–2.99
G7
C, Ho, S,
F
D
1.6
Main
Rare
3.59
–1.66
Tranovaltos
Veria
Petrographic notes
Marble composed of layers mainly of limpid calcite,
and subordinately of turbid finer-grained dolomite
(<0.5 mm), where non-carbonate minerals are
concentrated. Calcite is flattened
Marble composed of alternating layers mainly of
limpid calcite and subordinately of turbid dolomite
(greyish macroscopically). The calcite crystals are
flattened parallel to the foliation plane defined by the
micas. Accessories occur in the dolomite fraction
Very fine-grained marble composed of turbid dolomite and rare interstitial clear calcite. Minutely veined with white calcite. Graphite uniform throughout
and as veinlets
Cataclastic black marble made of fine-grained turbid
dolomite, crossed by coarse-grained white calcite
veins. Calcite is strongly deformed. Accessories related to dolomitic fraction
Cataclastic marble composed of oriented strained
calcite grains (up to 1.8 mm) set in fine-grained
(0.1 mm) unstrained calcite matrix. Turbid dolomite
is the only accessory present
Cataclastic marble composed mainly of coarsegrained and strained clear calcite grains and of subordinate fine-grained turbid dolomite. Accessories
concentrated into the dolomite, except quartz occurring in coarse calcite
Wine-red coloured calcite marble, foliated and schistose. Various kinds of accessories (particularly hematite) are very abundant throughout and also as thin
layers
Marble composed of strained calcite, showing disequilibrium geometries. Accessories absent
Very pure marble composed of limpid calcite grains
showing irregular borders. Rare apatite
Very pure marble composed of limpid calcite grains
with irregular borders. Rare Fe-oxides
Marble made of alternating light-grey and white
layers of calcite, showing variable grain size in adjacent layers, and flattened parallel to foliation plane.
Accessories concentrated in layers
White marble streaked in light grey, composed of
calcite showing equilibrium texture
Marble is mainly white but streaked in light grey. The
white portions are composed of calcite, the greyish
mainly of turbid dolomite. Accessories found mostly
in the dolomite fraction
Marble composed mainly of isometric grains of limpid calcite showing equilibrium relationships, and of
rare minute streaks of dolomite also showing equilibrium arrangements. Accessories very rare
Cataclastic marble made of discoidal calcite crystals,
flattened to generate a foliation plane, which are
girdled with small unstrained grains of calcite and
dolomite. Rare accessories
38
Table 1
(continued)
d13C
(‰)
1.88
d18O
(‰)
–3.73
Only
2.74
–6.96
0.1
Only
0.34
–3.75
Cr
0.1
Main
Sub.
–0.58
–1.44
Ho, S, A,
W-F
Cr to D
0.1–1.1 Acc.
Main
0.63,
0.59
–5.03,
–5.03
SK24
He, S,
W-A,
W-F
Cr to D
1.6
Main
Sub.
–0.06,
–0.13
–2.75,
–2.57
H2
Ho, G,
W-A,
W-F
Cr to St
0.1
Only
0.16a
0.51a
–5.27a
–5.54a
H19
He, G, I
Cr to St
0.1
Acc.
2.48a,
2.36 a
0.81a,
0.36 a
Keros
KE15
Ho, B,
microg.
NE
<0.1
Only
Paros
G5
Ho, G, I
Cr to St
3.2
Only
5.20
–3.29
LL
G, W-He,
W-F
Cr to St
1.8
Only
4.73
–3.31
PA2
Ho, G,
W-F, I
Cr to D, r. St 1.4
Only
5.11
–2.85
G11
He, G, I
Cr to D, r. St 11.0
Only
2.02
–5.56
G8
Ho, G,
W-A,
W-F
Cr to St
Acc.
1.23
–4.35
Locality
Sample
Texture
GBS
Volakas
VOL
Ho, G, F,
A
St
MGS Cal
(mm)
0.1–0.5 Acc.
Mires
217
C,
microg.
NE
<0.1
Talea Ori
G6
Ho, I,
microg.
NE
Folegandros
G2
C, He,
W-F
Sikinos
SK47
Iraklia
Naxos
1.0
Dol
Main
Main
Main
Petrographic notes
Fine-grained, foliated, dolomitic marble composed
mainly of layers with grain size close to 0.5 mm
alternating with finer-grained layers (0.1 mm). Equilibrium geometric configuration shown by dolomite.
Interstitial calcite present. Kaolinite forms spherical
aggregates
Very fine-grained cataclastic calcite marble containing coarse fragments of deformed calcite. Fe-oxides
present
Marble composed of very fine-grained calcite;
contains sparse spherical aggregates of minute calcite, cemented by sparry calcite. Quartz is the only
accessory
Cataclastic marble composed of fine-grained matrix
of calcite and dolomite, containing rare deformed
crystals of calcite (up to 1.0 mm). Quartz uniform
throughout
Marble composed of thin light-grey layers of dolomite variable in grain size (0.1–1.1 mm), and of
alternating rare white layers of flattened calcite.
Weakly foliated. Accessories in dolomite
Heteroblastic marble composed of layers mainly of
coarse calcite, with dolomite present, showing sutured borders, and subordinately of finer-grained layers
(0.2 mm) of calcite showing geometric equilibrium
relationships. Accessories mostly in dolomite fraction
Marble composed of alternating layers of isometric
white calcite and of turbid calcite (greyish macroscopically). Equilibrium textures present. Accessories
uniformly distributed
Marble composed of fine-grained turbid dolomite
preserving dismembered layers of coarse dolomite
(1.2 mm). Accessories frequent
Very fine-grained calcite marble veined by coarser
calcite. Sedimentary structures preserved. Accessories absent
Marble composed of calcite (mainly 0.6–1.2 mm)
with equilibrium geometries; coarser (4.0 mm) discoidal grains of deformed calcite, occasionally present. Accessories very rare
Marble composed of weakly flattened calcite grains,
mostly 0.4–1.4 mm in size, which show equilibrium
texture, particularly in the finer-grained portions.
Rare apatite present
Marble composed of weakly flattened grains of calcite, showing disequilibrium relationships. Accessories very rare
Coarse-grained heteroblastic marble composed of
calcite grains showing disequilibrium geometries.
Rare apatite present
Dolomitic marble composed of limpid dolomite, and
rare very thin layers of turbid calcite, which is substituted by dolomite. Geometric relationships of dolomite crystals straight to curved; those of calcite
grains, curved to dentate. Accessories frequent
39
Table 1
(continued)
d13C
(‰)
1.84,
1.78
d18O
(‰)
–5.55,
–5.78
2.02
–2.25
2.19
–1.67
Main
2.82
–4.01
Acc.
Main
–0.49,
3.05
–3.39,
–5.64
2.0
Acc.
Main
2.90
–4.34
Cr, r. St
5.0
Only
2.52
–0.85
Ho, G, I
St
1.0
Acc.
Main
2.99
–1.61
Marble composed of isometric grains of limpid dolomite showing equilibrium geometries. Calcite is accessory. Not carbonate accessories very rare
M1
He, S,
W-F
Cr to D
3.0
Sub.
Main
3.41
–2.15
M2
He, S, I
Cr to D
3.5
Only
3.01
–1.35
M3
He, S, I
Cr to D
2.2
Main
Rare
2.43
–2.80
M4
He, S, I
Cr to D
4.0
Main
Rare
3.86
–2.74
Balikesir/Kocoglu CT
He, S, I
Cr to D
7.0
Only
G21
Ho, S, I
D
3.5
Main
Sub.
4.02
–2.98
G28
He, S, I
D to Cr
3.0
Main
Sub.
4.14,
4.09
–3.27,
–3.37
Balikesir/Manyas G26
He, G, I
Cr to D
6.5
Only
3.92,
3.89
–1.16,
–1.19
Marble composed of matrix made of fine-grained
limpid dolomite and calcite, where strained layers of
coarser-grained calcite occur. Accessories frequent
Marble composed mainly of coarse-grained calcite,
and of a fraction (ca. 20% vol.) of finer-grained (ca.
0.8 mm) calcite, uniform throughout. Accessories
rare
and of a fraction (ca. 20% vol.) of finer-grained (ca.
0.8 mm) calcite, uniform throughout. Accessories
frequent
which is rimmed by fine-grained (ca. 0.7 mm) calcite
(ca. 20% vol.). Accessories not rare
which is rimmed by fine-grained (ca. 0.4–0.8 mm)
calcite (ca. 20% vol.). Accessories very rare
Marble composed mainly of isometric grains of limpid calcite and of subordinate finer-grained ochreous
dolomite. Accessories not found
Marble composed mainly of coarse-calcite and subordinate fine-grained turbid dolomite. Accessories
found mostly into the dolomite fraction
Marble composed of coarse calcite crystals, bent and
glide twinned. A fraction of finer-grained calcite
(0.5–1.4 mm) is uniform throughout. Rare apatite
present
Locality
Sample
Texture
GBS
MGS
(mm)
12.0
G17
He, G, I
Cr to D,
r. St
Tinos
G10
Ho, S, I
Ikaria
IK
Samos
Thasos
Only
Cr to D
0.4
Acc.
Ho, S, I
D to Cr
1.6
Only
KERK
C, He, S,
I
D
2.2
Only
G14
Ho, S, I
D
2.6
Acc.
G18
He, S, I
D
2.4
G15
Ho, S, I
D
TH3
He, S, I
F.Y.R.O.M. (Fig. 2)
Prilep
G19
Turkey (Fig. 3)
Marmara
Cal
Dol
Main
Petrographic notes
Marble composed of coarse calcite grains, deformed
(bent and showing secondary twins), contoured by
smaller grains of undeformed calcite (0.6–0.7 mm).
Accessories very rare
Fine-grained turbid dolomitic marble “spotted” with
rare dolomite “clasts” (up to 3.6 mm). Rare limpid
calcite interstitial. Accessories very rare
Calcite grains are bordered by accessory fine-grained
calcite. Accessories (microcrystalline silica and graphite) occur both in veinlets and interstitially
Mechanically deformed marble composed of calcite
grains bent and glide twinned. Rare thin sub-parallel
milonitic marble layers present
Marble composed of isometric grains of dolomite
showing disequilibrium geometries. Calcite is accessory. Other accessories very rare
Marble composed mainly of coarse-grained dolomite
showing disequilibrium geometries, and of a subordinate fine-grained fraction made of calcite. Accessories uniformly distributed throughout frequent
Marble composed of isometric dolomite showing disequilibrium geometries. Rare apatite
Coarse-grained calcite marble showing disequilibrium geometries
40
Table 1
(continued)
Locality
d13C
(‰)
3.62
d18O
(‰)
–1.66
Rare
1.75
–3.87
Rare
2.73
–5.36
Only
1.94
–3.59
1.5
Only
–0.66
–3.25
D
2.0
Main
Sub.
2.10
–3.47
Ho, S, I
D
0.4
Acc.
Main
0.87
–3.63
Ho, C, A,
F, S
He, C, A,
F, S
D
0.7
Only
0.52
–4.27
Cr to D
3.0
Main
1.11
–6.76
Cr to St
1.2
Only
0.79
–5.51
St-Cr to
Cr
St to Cr
1.2
Main
Rare
4.01
–4.96
1.4
Main
Rare
4.08
–4.86
Cal
Cr to D
MGS
(mm)
6.5
Ho, S, I
D
0.8
Main
PAV
He, S, A,
F, B
Cr
1.2
Only
21
C, F, A,
S
D
2.0
Main
Izmir (Teos)
180
He, S, A
D, r. St
4.0
Main
Aydin
178
He, S, I
Cr to D
4.0
Only
17
He, S, I
Cr to D
4.0
20bis
Ho, S, I
Cr to D
18
He, S, I
53
52
Afyon
Latmos
Sample
Texture
GBS
G13
He, G, I
179
93
95
Mugla/Salkim
Mugla/Golkuc
Dol
Only
Rare
Rare
G23
Ho, G,
A, F
Ho, G, I
G27
Ho, G, I
G24
Ho, S, I
D to Cr,
r. St
1.0
Main
Sub.
4.02
–5.58
G22
Ho, S, I
D to Cr,
r. St
1.0
Main
Sub.
3.94
–4.75
195
Ho, G, I
St
1.6
Main
Rare
Petrographic notes
Marble composed of coarse calcite crystals, bent and
glide twinned. A fraction of finer-grained calcite
(0.5–1.4 mm) is uniform throughout. Rare apatite
present
Marble composed mainly of isometric sutured calcite. Accessories very rare
Red marble composed of alternating layers of very
fine-grained (<0.1 mm) and of coarser calcite. Brecciated and veined by white coarse-calcite. Accessories very frequent
Discoidal grains of deformed calcite (defining one
foliation) are set into a finer calcite matrix. Accessories rare
Calcite marble showing great variability of size and
shape of calcite grains, which show dentate borders,
rarely straight. Occasionally equiangular triple junctions are present
Marble slightly heteroblastic (calcite in range 0.6–
4.0 mm) with disequilibrium geometries. Very rare
accessories uniform throughout
Marble slightly heteroblastic (calcite in range 0.6–
4.0 mm) with disequilibrium geometries. Very rare
accessories uniform throughout
Marble composed mainly of calcite almost constant
in grain-size (1.0–1.5 mm), with a finer (<0.8 mm)
very subordinate calcite fraction. Accessories uniform throughout
Marble composed of calcite (in range 0.8–2.0 mm),
besides subordinate fine-grained calcite and dolomite
(<0.2 mm) filling criss-crossing “veinlets”. Feoxides present
Fine-grained isotropic marble, composed of turbid
dolomite and accessory limpid calcite. Fe-oxides fill
veinlets
Marble composed of platy crystals of deformed calcite bordered with graphite
Marble made of calcite crystals, flattened to mark one
metamorphic foliation; secondary twins frequent.
Dolomite as minute aggregates. Accessories very
rare
Granoblastic marble, weakly foliated. Oriented white
micas prevail among the accessories
Homeoblastic, isotropic marble, showing equilibrium texture. Rare accessories
Marble composed mainly of limpid unstrained calcite, developing equilibrium texture, and of accessory deformed dolomite. Accessories occur mostly in
the dolomite fraction
Marble composed mainly of limpid unstrained calcite and of subordinate turbid and deformed dolomite. Opaques set mostly in the dolomite fraction;
other accessories occur in calcite
Marble composed mainly of limpid unstrained calcite and of subordinate turbid and deformed dolomite. Opaques set mostly into dolomite; other accessories occur in calcite
Granoblastic marble, distinctly isotropic and homeoblastic. Accessories very rare
41
Table 1
(continued)
Locality
Sample
Texture
GBS
176
C, He,
W-F,
W-A
C, B
D
G16
MGS
(mm)
0.4
Cal
<0.1
Only
Dol
d13C
(‰)
d18O
(‰)
Only
2.46
–2.62
Petrographic notes
Cataclastic marble made of very minute recrystallised calcite containing rare coarser calcite “clasts” of
former (protolithic) marble. Accessories very rare
Wine-red marble composed of fine-grained turbid
calcite containing hematite, brecciated and cemented
by white calcite veinlets. Accessories in small layers
Cal: calcite; Dol, dolomite. Texture: Ho, homeoblastic; He, heteroblastic; G, granoblastic; I, isotropic; A, anisotropic; F, foliated; B, brecciated; C, cataclastic;
S, sutured; W-, weakly-; microg., microgranular. Grain boundary shape (GBS): St, straight; Cr, curved; D, dentate; NE, not equilibrium texture; r., rarely; MGS:
maximum grain size; Acc., accessory; Sub., subordinate. C and O isotopes values: in italics (determinations at the Geologisches Institut, ETH-Zentrum); other
values determined at the Stable Isotope Laboratory, University of California). Carrara 1, Colonnata; Carrara 2, Monte Borla; Carrara 3, Boana Arnetola; Carrara
4, Torano; Carrara 5, Monte Altissimo. Eliconas 1, “Eliconas white”; Eliconas 2, “Eliconas black”.
a
Determinations repeated on separate fractions.
muscovite differs in the marbles from Carrara and Penteli
(Fig. 9). Muscovite from Tranovaltos and phengitic muscovite from Samos are chemically unique being enriched in Na
with respect to those of the other localities.
The distribution of the different types of micas among the
various localities is shown in Table 6. Muscovite is the only
mica occurring in the marbles from a number of localities
including Carrara, Tranovaltos, Samos (containing Na),
Mani, Aliveri, Prilep, Latmos and Mugla/Golkuc; by contrast, paragonite has been detected at Iraklia, Marmara and
Aydin, margarite and aspidolite are present only in the Marmara marbles, whereas phlogopite is common to Marmara
and Thasos, and is occasionally present at Paros and Naxos.
4. The accessory minerals as discriminants of marble
source
The analysed marbles come from geographically distant
and geologically unrelated sites, hence were generated from
separate protoliths, some kind of carbonate-rock (reasonably
different kinds of limestones), inevitably different in chemistry, possibly in the ratio of main components, i.e.
CaO/MgO, and certainly in the minor components. Whereas
the CaO/MgO ratio of protolith controls the type and the
proportion of carbonates present in marbles (i.e. in first
approximation, the calcite/dolomite proportion), minor components, which do not enter the carbonates structure, are used
Fig. 6. Position of the samples of marbles from Italy, Greece and F.Y.R.O.M. in the d18O–d13C reference diagram for the main Mediterranean marbles.
Reference isotopic fields from [24,25]. T: Thasos (T-1: Fanari district; T-2: Aliki district; T-3: Vathy-Saliara district); D: Dokimion (Afyon); N: Naxos; Pa 1–2:
Paros (Pa-1: Lychnites variety; Pa-2: Chorodaki valley; Pa-3: Aghias Minas valley); Pe: Penteli; C: Carrara; Pr: Proconnesos (Marmara). Analysed marbles.
Italy. Monte Altissimo: half-filled triangle. Greece. Penteli: asterisks; Eliconas: empty triangles upside; Agia Marina: cross; Mani: filled triangles down; Larissa:
filled triangles up; Tranovaltos: empty triangles down; Veria: empty star; Volakas: filled star; Mires: hexagon; Talea Ori: circled point; Sikinos: empty diamonds;
Iraklia: filled diamonds; Folegandros: half-filled diamond; Paros: empty circles; Naxos: filled circles; Tinos: empty square; Samos: filled square; Thasos: x.
F.Y.R.O.M. Prilep: half-filled circle.
42
Fig. 7. Position of the samples of marbles from Turkey in the d18O–d13C reference diagram for the main Mediterranean marbles. Reference fields from [24,25];
isotopic field of Iasos from [3]. D: Dokimion (Afyon); Pr: Proconnesos (Marmara) (Pr-1: main marble; Pr-2: marble from Camlik area); Aph: Aphrodisias
(Aydin); IS: Iasos. Analysed marbles. Crosses: Marmara (Sarajlar); filled circles: Balikesir/Manyas; open circles: Balikesir/Kocoglu; open stars: Latmos; filled
stars: Mugla/Golkuc (Iasos); filled triangles: Mugla/Salkim; open triangles: Aydin; open square: Afyon; filled square: Izmir (Teos: bigio antico).
up to generate the accessory minerals. Thus a few grains of
accessory minerals may provide a direct indication of the
chemical differences occurring among otherwise similar
marbles. As expected, Table 6 evidences that most accesso-
ries are not distributed uniformly among the investigated
marble localities, implying that they are potentially useful in
the characterisation of marble sources. Some mineral species
are particularly good tracers since, alone, they may point to
Table 2
Comparison between analyses performed by SEM and ARL electron microprobe
SiO2
Al2O3
MgO
CaO
Na2O
K2O
Carrara
Plagioclase
SEM
68.6
19.1
ARL
68.2
19.7
11.2
0.13
11.8
0.05
Muscovite
SEM
52.6
25.6
4.62
0.64
0.46
11.6
Marmara
Margarite
SEM
31.4
50.8
0.40
11.7
1.40
0.08
ARL
53.0
26.1
4.20
0.70
0.70
11.2
Phlogopite
SEM
40.0
18.7
25.3
0.10
0.87
10.0
ARL
32.0
49.7
0.20
12.0
1.45
0.10
ARL
40.5
18.4
26.0
0.50
10.4
Table 3
Selected analyses of plagioclase in marbles from type-localities of the Mediterranean
Locality
Aydin
Carrara
Mani
Mugla/Golkuc
SiO2
66.6
68.6
70.2
68.1
Al2O3
19.5
19.1
20.6
19.9
Fe2O3
CaO
0.41
0.28
0.30
K2O
Na2O
11.1
11.2
12.0
12.0
0.13
Table 4
Selected chemical analyses of amphibole and epidotes in marbles from type-localities of the Mediterranean
Accessory
Amphibole
Epidote
Allanite
Zoisite
Epidote
Locality
Mugla/Golkuc
Mugla/Golkuc
Mugla/Golkuc
Naxos
Tranovaltos
SiO2
56.8
37.8
32.4
38.7
38.6
Al2O3
1.35
22.3
18.0
33.5
26.0
FeO
4.31
12.9
10.5
10.8
MnO
0.30
1.55
MgO
21.5
0.95
CaO
9.62
23.7
15.6
25.3
23.1
Na2O
2.81
0.32
43
Table 5
Selected analyses of phyllosilicates of marbles from type-localities of the Mediterranean
Muscovite
Phlogopite
Margarite
Aspidolite
Paragonite
Kaolinite
Pyrophyllite
Montmorillonite
Chlorite
Aliveri
Afyon
Aydin
Balikesir/Kocoglu
Carrara
Iraklia
Latmos
Mani
Mugla/Golkuc
Paros
Panteli
Prilep
Samos
Sikinos
Thasos
Tranovaltos
Marmara
Mugla/Salkim
Naxos
Paros
Thasos
Marmara
Marmara
Iraklia
Marmara
Aydin
Afyon
Marmara
Naxos
Volakas
Afyon
Aydin
Afyon
Carrara
Mani
Mugla/Salkim
Mugla/Golkuc
Naxos
Penteli
Prilep
Thasos
SiO2
50.8
46.7
49.3
46.6
52.6
54.7
48.0
50.8
48.6
48.5
49.8
44.7
45.4
52.8
51.4
46.1
40.0
42.0
40.7
40.4
42.0
31.4
44.0
46.6
46.5
46.3
45.2
45.2
44.3
37.3
66.1
50.4
34.0
30.3
32.8
29.7
29.6
27.0
30.8
28.1
28.3
TiO2
0.84
0.14
0.38
0.38
0.43
0.25
the provenance of the host marble. For example fluorite
points to Anatolian marbles, in particular to Marmara,
Mugla/Salkim, or Balikesir/Kocoglu; zoisite to Naxos, and
rare earth-containing epidote to Mugla/Golkuc; aspidolite is
unique of Marmara, whereas margarite occurs at Marmara
and Samos, and paragonite at Marmara, Aydin and Iraklia.
Phlogopite occurs at Marmara and Mugla/Salkim among the
Anatolian marbles, and at Thasos, Naxos, Paros and Penteli
among the Greek marbles; it is worth noting that phlogopite
is absent from Carrara. By contrast plagioclase is typical of
Carrara and Aydin among the white marbles, and of Mani and
Mugla/Golkuc among the red coloured marbles.
Accessory minerals may be used successfully in combination with other parameters for the characterisation of the
marbles. Marbles isotopically similar, e.g. the marbles from
Al2O3
24.0
36.7
27.6
35.2
25.6
24.5
38.1
24.1
26.5
28.6
31.3
38.9
38.1
26.7
31.9
37.2
18.7
12.6
18.6
17.6
13.6
50.8
18.5
41.3
41.6
40.2
39.6
39.1
38.3
29.8
29.4
24.3
38.1
17.9
19.0
18.9
21.2
23.1
21.3
24.6
24.6
FeO
0.84
0.46
0.55
2.56
3.65
0.41
0.18
2.07
0.45
0.48
MgO
5.49
0.44
3.91
1.45
4.62
6.00
0.86
7.59
4.01
3.41
3.32
0.82
0.50
5.17
3.97
0.61
25.3
28.0
25.9
25.9
27.9
0.40
27.7
0.14
0.23
0.24
0.13
0.19
0.20
0.13
4.45
5.45
0.65
3.33
2.34
0.15
1.27
3.05
12.9
28.8
35.6
32.1
32.1
32.6
34.0
34.0
33.1
CaO
0.40
0.49
0.62
0.22
0.64
Na2O
0.42
0.69
0.34
0.54
0.28
0.18
0.23
1.54
0.27
0.85
0.77
0.77
1.45
2.80
0.44
0.33
0.54
0.10
0.24
0.16
0.54
11.7
0.66
0.61
0.47
0.60
0.34
1.06
1.11
0.38
0.29
1.75
0.55
0.44
0.35
0.18
0.39
0.08
0.23
1.49
0.58
0.40
0.46
1.16
0.87
0.77
1.62
2.52
0.87
1.40
6.73
6.46
7.87
6.93
K2O
9.61
9.83
9.50
11.4
11.6
11.5
9.45
10.6
10.6
10.6
11.0
10.1
6.93
10.2
10.7
9.56
10.0
11.0
9.46
8.12
10.8
0.08
1.62
1.50
0.58
1.62
0.14
1.03
0.13
0.29
0.30
0.26
1.05
0.82
0.27
0.59
0.34
Marmara, Thasos and Paros, which therefore cannot be distinguished by this parameter, may be discriminated internally
by the accessory minerals, considering that fluorite besides
aspidolite, paragonite and margarite occur only at Marmara,
where muscovite is absent; by contrast muscovite occurs at
Thasos and Paros. In turn Thasos and Paros marbles may be
discriminated by dolomite, which is common at Thasos and
is absent at Paros. Also marbles with similar MGS, e.g.
Carrara, Penteli and Eliconas, may be distinguished by accessory mineralogy: plagioclase occurs only at Carrara,
whereas muscovite occurs both at Carrara and Penteli (where
also phlogopite has been detected) and is absent at Eliconas.
Similarly marbles from Naxos, Thasos and Paros, which
overlap in MGS and isotope composition, may be distinguished by muscovite, besides titanite, zoisite, kaolinite,
44
Table 6
Distribution of accessory minerals in marbles from type localities of the Mediterranean
A
Italy (Fig. 1)
Carrara-1
Carrara-1
Carrara-1
B
C
1
1
1
A13 X
A24 X
A21
Carrara-2
Carrara-2
Carrara-3
1
1
1
A5 X
A37
A31
Carrara-3
Carrara-4
Carrara-5
Greece (Fig. 2)
Penteli
1
1
1
A16 X
A22 X
MA1
X
1
G9
Tranovaltos
1
1
2
2
3
4
5
5
6
6
7
G12
G1
G3
G4
AM
136
PA3 X
134
137
138
TR1
Veria
Volakas
7
7
7
8
9
TR2
TR3
TR5
G7
VOL
10
11
12
13
13
217
G6
G2
SK47
SK24
14
14
H2
H19
15
16
16
16
17
17
KE15
G5
LL
PA2
G11
G8
Tinos
17
18
G17
G10
Ikaria
Samos
19
20
IK
KERK
Eliconas 1
Eliconas 2
Agia Marina
Aliveri
Mani
Larissa
Mires
Talea Ori
Folegandros
Sikinos
Iraklia
Keros
Paros
Naxos
Ab Q
Sp
Ap Su
Ti
F
Z
Ox Ep
Am Ch K
Py
Mt Mu PM SPM Ph
As
Pa
Ma Hy G
X
Ti;
Fe
Fe
Fe
X
X
Fe;
V
X
X
X
X
Fe
X
X
Fe
X
X
X
Fe
X
X
Fe
X
X
X
X
Ti;
Fe;
Mn;
Cr
X
X
?
X
X
X
X
X
X
X
Ti
Fe
X
HE
X
X
X
Fe
Fe; E
Ti
Fe
Fe
X
X
X
X1
X
X
X
X
X
X
X
Fe;
Ti
Fe
X
X
X
X
X
X
Fe;
Ti
X
X
X
Fe–Ti;
Fe
X
X
X
X
(*) X
X
X
s
X
X
X
X
X
X
X
Fe
Fe;
HFe;
Ti
X
X
Z
X
X
X
Fe;
HFe
X
X
X
X2
45
Table 6
(continued)
A
Thasos
B
21
21
21
21
F.Y.R.O.M. (Fig. 2)
Prilep
22
Turkey (Fig. 3)
Marmara
1
1
1
1
Balikesir/Kocoglu 2
2
2
Balikesir/Manyas 3
3
Afyon
4
4
4
Teos
5
Aydin
6
6
6
6
Latmos
7
7
7
7
Mugla/Salkim
8
8
Mugla/Golkuc
8
8
9
9
9
C Ab Q
G14
G18
G15
TH3
Sp
Ap Su Ti
X
X
X
X Fe;
Zn
G19
X
M1
M2
M3
M4
CT
G21
G28
G26
G13
179
PAV
21
180
178
17 X
20bisX
18
53
52
93
95
G23
G27
X
X
X
X
X
G24
G22
195
176
G16 X
X
X
X
X
X
X
X
X
F
Z
Ox Ep
Am Ch K
X
Fe
Mt Mu PM SPM Ph
X
X
X
X
Ti
Fe
Py
X
X
Ti
Pa
Ma Hy G
X
X
X
X
X
As
X
X
X
X
X
X
X
X
X
X
X
Fe
X
Fe
HE
Fe
X
X
X
X
X
X
X
s
X
X
X
X
X
Fe
Fe
Fe
Fe
X
X
X
X
X
X
X
Fe
Fe
Fe
Fe
X
X
Fe
Fe
X
X
X
X
X
X
X
Fe;
HFe
Fe
Fe
X
X
X
Fe
X
X
X
X
HE E; T
RE
X
X
X
X
A, country; B, location of samples on maps of Italy, Greece, and Turkey; C, sample label. Ab, albite; Q, quartz (s, microcrystalline silica); Sp, Al–Mg–Ti-spinel
(?) (*); Ap, apatite; Su, sulphide (Fe, Fe-sulphide; V, Cu–As–V-sulphide; Zn, Zn-sulphide); Ti, titanite; F, fluorite; Z, zircon; Ox, oxide (Fe, Fe-oxide; HE,
hematite; Mn, Mn-oxide; Cr, Cr-oxide; Ti, Ti-oxide; Fe–Ti, Fe–Ti-oxide; HFe, Fe-hydroxide); Ep, epidote (E, Fe-epidote; Z, zoisite; RE, rare earths-rich
epidote); Am, amphibole (T, tremolite); Ch, chlorite; K, kaolinite; Py, pyrophyllite; Mt, montmorillonite; Mu, muscovite (Si f.u.: <3.1); PM, phengitic muscovite
(Si f.u.: >3.1 and <3.4); X2, Na-rich phengitic muscovite; SPM, strongly phengitic muscovite (Si f.u.: >3.4); X1, Na-rich muscovite; Ph, phlogopite; As,
aspidolite; Pa, paragonite; Ma, margarite; Hy, hydralsite (?); G, organic substance (graphite). Carrara 1, Colonnata; Carrara 2, Monte Borla; Carrara 3, Boana
Arnetola; Carrara 4, Torano; Carrara 5, Monte Altissimo. Eliconas 1, “Eliconas white”; Eliconas 2, “Eliconas black”.
which occur at Naxos and not at Thasos and Paros. The
important Anatolian marble-types, Aydin (Afrodisia), Afyon
(Dokimion) and Marmara, which overlap isotopically, may
be distinguished internally by accessory minerals. In particular plagioclase occurs only at Aydin, where also muscovite
occurs at variance with Marmara; Fe-oxides are common at
Aydin and Afyon, whereas Fe-sulphides and Ti-oxides have
been detected at Marmara. The Anatolian fluorite-bearing
marbles (i.e. Marmara, Mugla/Salkim and Balikesir/
Kocoglu) may be distinguished mutually by chlorite and
Fe-oxides (unique to Mugla/Salkim), and by micas (with
muscovite possible at Balikesir, and phlogopite, paragonite
and aspidolite, unique at Marmara) besides kaolinite (occurring only at Marmara). Marbles of some localities (e.g. Agia
Marina, Keros, Mires) do not contain accessories.
5. Conclusions
A number of marble samples coming from different localities of the Mediterranean, including those exploited in the
ancient past and archaeologically important, e.g. Carrara,
Penteli, Naxos, Paros, Thasos, Marmara, etc., have been
analysed for C and O isotopes and examined petrographically.
46
marbles. A number of minerals were recognised: quartz,
plagioclase, apatite, various kinds of sulphides and oxides,
different types of micas (muscovite, phlogopite, aspidolite,
paragonite, margarite), chlorite, kaolinite, pyrophyllite,
montmorillonite, epidote, amphibole, besides organic substance. These mineral species and their morphology may be
used to identify the provenance of archaeological marbles.
Acknowledgements
Some samples from Greece and Turkey were kindly provided by C. Gorgoni (Modena University) and L. Lazzarini
(Venice University), who are cordially acknowledged. Two
unknown Referees are gratefully acknowledged for improvement of text. Financial support was given by the Italian
CNR—Progetto Finalizzato BENI CULTURALI (grants
C.N.R. 99.03718.PF36 and 01.00500.PT36).
Fig. 8. (Aliv + Alvi) (f.u.) vs. Si (f.u.) of muscovites of marbles from type
localities.
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Fig. 9. Mg (f.u.) vs. Si/Al (f.u.) of muscovites of marbles from type localities. Grey circles: muscovites from Penteli marble; black circles: muscovites
from Carrara marble; empty circles: other localities.
As expected, the isotopic composition of marbles from the
classical sources of antiquity, compares fairly well with the
literature data, but they are not sufficient to identify the
provenance of all stones.
The salient petrographic features (texture, MGS and GBS
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Accessory minerals and δ18 O and δ13 C of marbles from the

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