Geomorphodiversity of the San Lucano Valley

Geoheritage
DOI 10.1007/s12371-013-0079-3
CASE REPORT
Geomorphodiversity of the San Lucano Valley
(Belluno Dolomites, Italy): a Well-Preserved Heritage
Bruno Testa & Barbara Aldighieri & Alberto Bertini &
Wolfgang Blendinger & Grazia Caielli &
Roberto de Franco & Danilo Giordano &
Evelyn Kustatscher
Received: 5 April 2012 / Accepted: 28 February 2013
# The European Association for Conservation of the Geological Heritage 2013
Abstract The San Lucano Valley (Belluno, Italy) was the core
topic of the symposium: "L'armonia fra uomo e natura nelle
valli dolomitiche” held in Agordo (Belluno) on the 12th and
13th November 2010. In this work the valley is analysed
according to the following features: geological, geomorphological, structural, stratigraphic and ecological. The purpose of this
paper is to review these features in order to establish the origins
underlining the intrinsic geomorphodiversity of this unique area
in dolomites. By walking along the river and observing landscape geomorphology or reading micro- and macroscale evidence on the mountainsides, the valley clearly reveals the keys
to comprehending the geological history of dolomites from
Triassic to present. A full list of geomorphosites has been
appended in order to improve the scientific documentation of
this valley.
Keywords Geomorphodiversity . Landform evolution .
Fossil plants . Knickpoint . Seismic stratigraphy .
Geomorphosite
B. Testa (*) : B. Aldighieri : G. Caielli : R. de Franco
Institute for the Dynamics of Environmental Processes - National
Research Council, Via Mario Bianco 9,
20131 Milano, Italy
e-mail: [email protected]
A. Bertini : D. Giordano
Technical Industrial Institute of Mining “U. Follador”,
Agordo (BL), Italy
W. Blendinger
Technische Universität Clausthal, Geology and Paleontology
Institute Clausthal University of Technology, Leibnizstr. 10,
38678 Clausthal-Zellerfeld, Germany
E. Kustatscher
Museum of Nature South Tyrol, Via Bottai 1,
39100 Bolzano, Italy
The San Lucano Valley: a Rich Geomorphodiversity
Inherited from a 200 Million Years Old History
As defined by Panizza (2009), geomorphodiversity is a
critical evaluation of geomorphological characteristics of a
territory. Based on such a study, some peculiarities of the
Dolomites Mountains, when compared with other alpine
chains, both European or extra-European, are considered
"unique" in relation to the forms of "structural" relief that
show. In particular, they show such a high degree of extrinsic geomorphodiversity to be potentially worthy of the
UNESCO listing of “World Heritage” status (Gianolla et
al. 2008). These intrinsic characteristics reinforce the reasons for such a definition, and those located in the San
Lucano Valley were in 2009 considered to be part of
World Heritage area (Fig. 1).
Geological Framework
The San Lucano Valley is a deep valley carved into the
carbonate platform of the Pale di San Martino–Civetta, the
largest of Ladinian cliffs of the Dolomites. The Pale di San
Martino group is slightly curved into a gentle syncline
(Leonardi 1968; Doglioni 1987, 1992; Castellarin et al.
1996) and settled between the line of Valsugana, the geological southern limit of the Dolomites and a back-thrust
connected to the same. The geological complexity of the
valley is remarkable. The oldest strata belonging to the
Werfen Formation, which is overlain with a heterogeneous
Anisian sequence witnessing an intense phase of tectonic
activity coeval to sedimentation, which continued even during the Ladinian (i.e. volcano tectonics). The Valley is a
privileged place to observe the relationship between carbonate reef, basin and Middle Triassic magmatism (intrusive
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Fig. 1 Geographic sketch of
Agordo Area: San Lucano
Valley belongs to the third
Unesco System
and extrusive with sedimentary volcaniclastic rocks) which
are directly connected to the genesis of the landscape.
The outcrops in the San Lucano valley range from Lower
(Werfen Formation) to Upper Triassic (Cassiana Dolomite)
and although the time interval is relatively short (about 20
million years), they are abundant and varied due to the
magmatism of Cima Pape. For this reason, it is better to
refer to a stratigraphic relationships model (Fig. 2) instead of
a conventional stratigraphic column.
The Morpho-Structural Heritage (Secondary and Tertiary
Eras)
Lithology and Tectonics Factors Determining
"Geomorphodiversity” of the S. Lucano Valley" and "Pale
di San Lucano"
Morphotectonics (or morpho-tectodynamics) studies the relationship between relief forms and tectonic movements
(Panizza 1992), that is, the geomorphological consequences
of diastrophic shifts that have occurred from the beginning of
the area’s geological history until now. In this case, the
existing San Lucano Valley drainage network is a Late
Miocene heritage and by examining the temporal relationship
between tectonic setting and waterways one can observe that
the valley of the Cordevole river follows the first uplift phase
(Sella-Tofane zone) before the raising of the Valsugana
Anticline, cutting sharply in a NS direction. The rapid anticlinal uplift in the Pale di S. Martino area, generated a series of
stream valleys oriented along the structural slope (i.e. consequent valleys), for instance the Angheràz Valley (Fig. 3). The
San Lucano Valley has an E-W orientation and has the characteristics of a subsequent valley, parallel to the tectonic axis,
where weak formations and/or tectonic factors are present
controlling the valley setting. The peaks of the chain Agnèr–
Croda Grande (Fig. 4) as well as the Pale di San Lucano
(Fig. 5) are furrowed by deep gullies (“borai”, “van”), were
the rocks are cataclastic, easily eroded and associated with a
fault and fracture network (Angheràz Valley, Fig. 3).
The morpho-tectodynamic processes found in San
Lucano Valley are obvious landscape dynamic examples,
with significant gradients between mountain peaks and valley floors. The Dolomite’s peaks are sculpted along fractures in the form of towers, spears, pinnacles and ridges,
such as the Agnèr Mt. (Figs. 4 and 10). They are also a
perfect example of the original Mesozoic shelf slope, which
slopes down to the basin bottom.
Based on both bibliographic data and field observations,
two geological sections were drawn (Fig. 6): the first cuts
the valley at Mezzavalle NS from San Lucano Mt. to Spiz
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Fig. 2 Simplified relationships
diagram of San Lucano Valley
(more information in Giordano
2011): 1 Werfen Formation, 2
Lower Serla Dolomite, 3
Voltago Conglomerate, 4
Agordo Formation, 5
Richthofen Conglomerate, 6
Morbiac Limestone, 7 Contrin
Formation, 8 Moena Formation,
9 Livinallongo Formation, 10
Sciliar Formation, 11
Monzonite, 12 Pillow lava, 13
Monte Fernazza Formation, 14
Wengen Formation, 15
Cassiana Dolomite
d’Agnèr, the second, with a direction NW-S from Lastia of
Gardès to Agnèr Mt. In the first example, the profile is quite
symmetrical, whilst the second section underlines the strong
asymmetry of the valley’s profile, which is not attributable
to the direction of the line of section. The steeper north side
(Pale di San Lucano) is supported by layers of tenacious
dolomite, perpendicular to the slope and cut by a fault. The
Anisian-Scythian formations outcropping at the foot of the
wall are partly covered by slope debris and rockfall rubbles.
The Agnèr Anisian layers on the southern side, however, are
fractured and tend to induce landslides. The asymmetric
shape of the basin seems also to be attributable to structural
Fig. 3 Angheràz and Reiane
valleys viewed from the
southern side of Cima dei
Vanediei. Centre of picture the
Bordina creek valley truncates
the Ladinian reef. S Schlern
formation, L formation of
Livinallongo, V volcanics; 1
Pian della Stua landslide, 2
deep gravitational slope
deformation below the Pale dei
Balcoi, 3 active debris flow in
Angheràz Valley
controls (Giordano 2011). Indeed, the geomorphology and
geomorphic indexes (Testa and Aldighieri 2011) support the
hypothesis of a primordial structural-type control of the
valley, over which early glacial, fluvioglacial and finally
fluvial processes modelled the valley (Bini et al. 1999;
Castiglioni 1964; Giordano 2011; Caielli and de Franco
2011).
The result is that Quaternary deposits of both postglacial
landslides and debris flows are more extensive and powerful
on the southern slopes, inducing a gradual northwards migration of the Tegnas thalweg where debris contribution is
less frequent.
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Fig. 4 The Agner–Croda
Grande chain and the
underlying Angheràz Valley.
The influence of tectonics in
landscape genesis is very clear:
the highest peak (the Agnér
Mt.) is separated from Spiz
d'Agnér (left) and the Torre
Armena (right) by a double
gullies fault. Further to the
right, the Van delle Scandole is
set on a transcurrent fault, while
the intense tectonics sculpts the
crest of Angheràz Valley into a
piers and pinnacles landscape
Due to the morpho-tectostatics, the rectilinear direction
of the San Lucano Valley owes its origin to the presence of
structural faults. A hypothetical fault line cutting the valley
lengthwise, below the Quaternary cover, accounts for the
different thickness of the Anisian formations on both sides.
These important facts are confirmed in high-resolution seismic surveys carried out near the church of San Lucano
(Caielli and de Franco 2011). More specifically, there is no
evidence of active or recent tectonics, marked by fault
scarps and plans, incisions and torrents, river bends, dislocations of the ridge etc.
Morphoselection is generated by selective or differential
erosion when geological structure plays a passive role. If
one refers to the lithological composition, this can be termed
morpho-lithology. When rocks are subject to the erosive
action of morphogenetic agents (rivers, glaciers, snowFig. 5 View of Pale di San
Lucano Group from Grotta di
San Lucano. The slope to the left
of Lastia di Gardes is a structural
surface coinciding with the Pale
di San Lucano cliff slope, its
inclined stratification well
visible; on the other hand, on top
of Spiz Lagunaz, layers are
horizontal (inner lagoon, Sciliar
Formation). At the base of the
Terza Pala a fault (in red) parallel
to the wall is shown, whilst a
large mirror tilted fault can be
detected just below the summit.
F.A. Agordo Formation, F.C.
Contrin Formation, C.M.:
Morbiac Limestone, F.S. Schlern
Formation, F.L. Livinallongo
Formation
frost, karst etc.) they have "morphological responses"
according to their mechanical and lithological characteristics. The variety of rock formations leads to a selective
series of shape types, with steep cliffs and peaks in contrast
to more gentle slopes, for example arenaceous-marly slopes
below steep thick walls of dolomitic limestone. Hence, the
San Lucano Valley lithotypes can be divided into the following four classes (Fenti et al. 2001), including rocks with
similar behaviours:
A. Alternation of different lithological layers (sandstones,
siltstones, marly limestone, marl and dolomite). The
mechanical strength at the sample scale is variable,
but the layers show a homogeneous mechanical behaviour, determined by the dense layering and lithological
alternation. They are characterised by a lack of
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Fig. 6 Geological crosssections through the San
Lucano Valley: 1 Quaternary
deposits: alluvial/debris and
landslides, 2 Wengen
Formation and M. Fernazza
Formation (Upper Ladinian), 3
Monzonites, gabbros and
sienites (Upper Ladinian), 4
Sciliar Formation and Cassiana
Dolomite (Ladinian–Carnian),
5 Livinallongo Formation and
Moena Formation (Lower
Ladinian), 6 Contrin Formation
(Upper Anisian), 7 Morbiac
Limestone and Richthofen
Conglomerate (Upper Anisian),
8 Agordo Formation and Lower
Serla Dolomite (Anisian), 9
Werfen Formation (Scythian)
morphologic evidence, mild and rounded forms, not very
steep slopes, ledges, low rock walls and are easily eroded
because they have been shattered by frost action (Werfen
Formation; Voltago Limestone, Richthofen Limestone,
Morbiac Limestone; Moena Formation, Livinallongo
Formation; Zoppé Sandstones, "Heterogeneous Chaotic").
B. Volcanic rocks, sub-volcanic, conglomeratic rocks and
volcaniclastic sandstone. The cliff rocks are coarsely
stratified and not very fractured. They have medium to
Fig. 7 Boral di Lagunàz. The
wall shows different degrees of
erodibility of anisian
formations. Agordo Formation
(F.A.), Richthofen Limestone
(C.R.), Morbiac Limestone
(C.M.), Contrin Formation
(FC), the trace (red) of a fault
plane is also shown
high morphological hardness, and reach to more than
100 m in height. Due to their basic composition they
are subject to surface alteration and break up easily (e.g.
monzonites, latites, andesites, basalts of the M. Fernazza
Formation and the "Marmolada Conglomerate").
C. Dolomites, carbonate rocks, limestones, arenaceous
limestones and sandstones layers outcrops in thick
compact decametric layers. However, the total thickness of the formation is generally moderate, so they
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Fig. 8 Cascata dell’Inferno
along the Bordina creek is a
classic example of selective
morphology; the threshold is
carved in Agordo Formation.
Under the waterfall, on the
right, separated by a fault, the
colourful Voltago Limestone
layers outcrops
generate large steps from 10 to 50 m high, connected by
inclined ledges. Here the morphologic evidence is
medium-high, as these are poorly degradable rocks, although being subject to rockfall by undermining of weaker rocks at their foot (Lower Serla Dolomite, Agordo
Formation, Morbiac limestone and Cassiana Dolomite).
D. Carbonate rocks, dolomite and limestone in massive
formations of hundreds of metres thickness. They have
a solid limestone-dolomite appearance or are sometimes decayed and with cavities, heavily layered or
without stratification; the morphologic evidence is very
high, they form sub-vertical, vertical and overhanging
cliffs, towering several hundred metres (Pale di San
Lucano, Agnèr Mt. etc.) and are less erodible and
Fig. 9 The Cima dei Vanidiei
represents a classic example of
a structural crest with slightly
inclined layers, originated by
selective erosion. The top layer
is constituted by thick tenacious
layers of Marmolada
Cconglomerate. On the hillside
below, outcrops layers of the
less resistant of Fernazza Mt.
Formation. Where slope
increases, pillow lavas outcrop
too
degradable. The high slope causes rock falls (Contrin
Formation, Sciliar Formation).
This classification is reflected in the detailed review of
the morphological evidence observed on the valley sides
(Pale di San Lucano, Bordina Valley, Agnèr Mt. and
Angheràz Valley). By observing the profile of the Terza
Pala from the base, the layers of Werfen Formation and
Serla Dolomite (Fig. 5), partially covered by landslide deposits, make a gentle slope, then a first step corresponds to
the Agordo Formation bank, the Richthofen marly arenaceous and Morbiac limestone layers then form another gentle slope interrupted by the overhanging wall of Contrin
Formation before reaching the summit carved in the Sciliar
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due to selective erosion are the Cima dei Vanidiei structural
crest (Fig. 9) and the steps of Prademur Mt. slope.
Pale di San Lucano: a Unique Example of Platform
Carbonates and Their Dolomitisation
The development of the Pale di San Lucano (Fig. 5) deserves special attention due to its importance for studying
dolomitisation. Here, it is possible to recognise a first generation of reefs (pre-volcanic and syn-volcanic Sciliar
Formation) prograding first and then aggrading, with a final
layer of the overlying Carnian rocks (De Zanche and
Gianolla 1995, Blendinger et al. 2007). Both are part of a
curved carbonate platform which delimits the volcanic centre of the Triassic Dolomites in their southern and eastern
sectors (Fig. 10). The thickness of approximately 1.5 km of
Middle Triassic (242–238 Ma) carbonates is of exceptional
importance for two reasons:
Fig. 10 Edge and the north face of Agnér Mt
Formation. Beneath the Lastia of Gardès, an initial 50–60 m
high wall carved in "Morbiac" nodular limestone pushes
upwards with a large sloping ledge moulded into thin layers
of Livinallongo Formation. The slope continues vertically
with the Sciliar Formation, occasionally interrupted by
Livinallongo Formation and Sciliar Formation interdigitations. Observing the Boral di Lagunaz, on the left side of the
valley, from the San Lucano church the step modelled by the
Agordo Formation can be easily recognised, protruding
from the eroded mountainside profile (Fig. 7).
The Cascata dell’Inferno, along the Bordina stream, is also
a typical example of selective erosion (Fig. 8). In the upper
part of the Bordina valley, the effects of the heterolithic facies
of the Ladinian on the landscape are very striking. Other forms
Fig. 11 Three-dimensional
model of the Contrin Formation
under the Pale di San Lucano,
looking northward, and
hypothesis of its internal
stratification. The Contrin
"platform" is not just an
aggrading platform, but it shows
a "mound" under the Quarta Pala
and laterally migrates to the
basin and towards stratified
carbonate sediments
1. The Pale di San Lucano is one of the very few examples
where a progradational platform top is directly visible.
The other two examples are the Capitan reef complex
(Permian) in North America, and the Pighera Mt., the
southernmost outlier of the Civetta massif adjacent to
the Prima Pala di San Lucano. The progradational interval is about 110 m thick and thins out towards the
NW. The bedded carbonates are laterally replaced by
steeply inclined clinoforms (30–45°) and contain a
“marker bed” (Fig. 11) about 3 m thick, which corresponds to the maximum progradation and provides evidence of the volcanic “event” of the Dolomites.
Progradation was about 750 m to the NW, but the full
symmetry is nowhere preserved. Therefore, it is not
clear whether the progradational interval was a genuine
“platform top” or merely a terrace at the foot of a mound
chain in the SE, such as the chain of Agnèr Mt.
2. A potentially greater importance is from a
geomorphodiversity point of view, as the progradational
interval offers a unique possibility to resolve the mystery
of dolomitisation of the Dolomites, because of its only
partially dolomitised. In the same outcrop, two types of
dolomite occur: a white, saccharoid type (Figs. 12 and
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Fig. 12 a Thin section of a saccharoid dolomite with several small
tubular voids like bacteria colonies, in blue due to impregnation with
coloured plastic. The preservation of the round shape, smaller than
dolomite crystals, suggests that dolomite recrystallised before the bacteria disappearance. b Thin section of a "cycle cap"- type dolomite, cut
Fig. 13 Direct contact between a saccharoid dolomite and a yellowish
"cycle cap"-type dolomite bank
by a vertical fracture filled by saccharoid dolomite. The micritic texture
“boundstone”-type is very similar to limestone, even if macrofossils
are not present. Voids are filled by fibrous dolomite, but a light porosity
still remains
13) and a yellow to white very finely crystalline type. The
limestone is typically pale grey and, in thin section,
shows a boundstone fabric which is very similar to travertine, but a sparse marine fauna is often present. Relict
structures are also well preserved in most of the dolomites, indicating that they are a dolomitised limestone.
Limestone passes both laterally and vertically into dolomite, showing numerous dolomitisation fronts, in which
the calcite passes into pure dolomite within a few
decimetres (Fig. 14). These dolomitisation fronts are also
peculiar because of the mineral paragenesis: the dolomite
crystals are corroded by fibrous calcite cement, which is
the most important cement mineral in the adjacent limestone. This indicates a very early dolomitisation at the
sediment water interface and immediately below. The
yellow dolomite is similar to the so-called “cycle caps”
of the Latemar, but its vertical and lateral distribution is
very irregular and most likely to not be the result of
subaerial platform exposure (Fig. 15). Another peculiarity of the Pale di San Lucano carbonates is the geochemical record, which is, of course, not observable in the field
but requires laboratory measurements (for more details
see also Blendiger et al. 2011). The dolomitisation of the
Pale di San Lucano was most likely caused by fluids
sinking through the platform, as a continuous process
accompanying deposition, but it is not yet entirely clear
what caused the distribution of limestone and dolomite
and the higher-than-seawater density of the fluids. The
so-called ‘reflux model’ has long been suspected to be
responsible for the dolomitisation of other platforms in
the Dolomites, but has recently been challenged in favour
of a hydrothermal model with exactly the opposite flow
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Fig. 14 Net, but wavy shaped,
contact between a limestone
and a saccharoid dolomite in a
bank. The 87Sr/86Sr ratio values
are outside the marine field in
both rock types
direction. The problem has not yet been conclusively
resolved and the Pale di San Lucano continues to be a
key natural laboratory to test dolomitisation models.
Fossils Plants: an Added Value to the Geomorphodiversity
Plant fossils are generally rare in the Dolomites, although
remains are known from the Upper Permian (e.g.
Bletterbach, Cuecenes, Mölten), from the Middle Triassic
(Anisian, e.g. Kühwiesenkopf/Monte Prà della Vacca, Piz da
Peres; Ladinian, e.g. Seewald, Ritberg, Corvara) and from
the Upper Triassic (Carnian, Heiligkreutz, Stuores Wiesen,
Rifugio Dibona). For more details, see Wachtler and Van
Konijnenburg-van Cittert (2000), Visscher et al. (2001),
Broglio-Loriga et al. (2002), Kustatscher and Van
Konijnenburg-van Cittert (2005), Kustatscher et al. (2004,
Fig. 15 3-D model of dolomite and limestones belonging to the
prograding portion of Pale di San Lucano, seen from the SSE. a Block
diagram resulting from interpolation among mineralogical facies of
two dolomite type and limestone. b The same model "eroded" by the
underlying progradation surface and the topographic roof, showing the
current distribution of layers
2010, 2012). The discovery of plant fossils from the Middle
Triassic of Agordo area, therefore, adds important information on the composition of the Middle Triassic vegetation
and on the distribution of emerged land during this time
period (Kustatscher et al. 2011).
Palaeogeographic reconstructions for the Anisian (lower
Middle Triassic) suggest a marine environment with an
extensive island extending over the northern and central
Dolomites. Several plant horizons have been found north
and west of this island, but until now only limited information was available on its southern extension.
The recovery of plant fossils in Anisian sediments of San
Lucano Valley is, therefore, of particular palaeogeographic interest and, furthermore, increases the valley geomorphodiversity—
even though only a few plant fragments (~30) have been
recorded. These plant fragments belong to the horsetails, ferns,
seed ferns, cycads and conifers. The most abundant group in the
flora are the conifers which include Voltzia sp., which is particularly interesting because it shows some characteristics that have
never been described in the Dolomites. The lateral shoots arise
alternately from the main shoot and are covered densely and
helicoidally by the leaves. The leaves are fine, narrow and falcate
and referred to Voltzia recubariensis (De Zigno) (Schenk 1868;
Broglio-Loriga et al. 2002). The genus Albertia is well known
from the Anisian of France (Grauvogel-Stamm 1978). The
horsetails are represented by stem and rhizome fragments, both
probably belonging to the genus Equisetites. Unfortunately, the
missing microphylls on the stem fragments does not allow a
more detailed taxonomic attribution. The ferns are represented
by four different taxa: Anomopteris Brongniart 1828,
Neuropteridium voltzii (Brongniart) Schimper 1879 and
Scolopendrites sp. are typical for the Anisian of France and
Germany (Fuchs et al. 1991) and belong to the Osmundaceae,
a family today well distributed in the tropical and subtropical
area. Cladophlebis remota (Presl) Konijnenburg et al. 2006 is a
species well known in the Ladinian and Carnian of Europe (e.g.
Heer 1877; Leonardi 1953; Kustatscher and Van Konijnenburgvan Cittert 2005). Only one fragment of a female organ with an
Geoheritage
Fig. 16 a Fragment of
Equisetites beam; b Plants of
Equisetum, a recent sfenofita
umbrella-like shape (Peltaspermum sp.) belongs to the seed
ferns. A single leaf fragment of the cycad Taeniopteris sp. has
been found, an entire margined lamina with no secondary
bifurcating.
The flora found in Agordo Formation, although only fragmentarily preserved, corresponds to a typical Anisian flora. The
main markers such as Equisetites (Fig. 16) in the sphenophytes,
Anomopteris (Fig. 17), Neuropteridium/Scolopendrites in the
ferns and Voltzia (Fig. 18) and Albertia (Fig. 19) in the conifers
are all there. Additionally, there are fragments of the seed ferns
(Peltaspermum) and cycadophytes (Taeniopteris) that are well
documented from the Anisian of the Dolomites (e.g. BroglioLoriga et al. 2002) but appear in the fossil record of the
Germanic Basin mostly within the Ladinian. Although the area
has an important and complicated geological history with
synsedimentary tectonics, the plant fossils of Agordo
Formation reflect a well-defined flora. The plant remains are
mostly fragmented and small and often badly preserved, indicating a long transport from the growing to the depositional
area (Kustatscher et al. 2011). The relative high amount of fern
fragments in the flora, considering biases due to taphonomic
Fig. 17 a Fragment of
Anomopteris mougeotii beam; b
plants of Osmunda regalis
selection, indicates that the flora was rich in ferns, probably
reflecting a warm and humid climate. Additionally, the flora
shows the presence of some emerged lands nearby, covered by
the Anisian vegetation typical of the Dolomites (Kustatscher et
al. 2011).
The Quaternary Heritage
Glacial Landscape
The Cordevole valley is a very ancient fluvial valley (Upper
Miocene), which existed prior to the Belluno Dolomites uplift
but continued to be excavated during the latter period. The
first major glacial expansion dates from 2.4 Ma. From this
date until the first part of the Quaternary (0.9 M.y. BP), many
moderate glacial fluctuations have occurred (Bini et al. 1999).
During the Last Glacial Maximum (LGM), the "Cordevole"
glacier in the Agordo zone exceeded 1,500 m in altitude
(Castiglioni 1940) and it joined the glaciers coming from the
Civetta (Corpassa Valley) and Pale. The secondary San Lucano
Valley is unexpectedly wider and deeper than the main
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Fig. 18 a Detail of Voltzia sp.
branch with visible falciform
needles; b branch of Araucaria
plant
Cordevole Valley—this can be explained by its geographical
position which is characterised by higher rainfall than the rest
of the Dolomites and the ‘zero isotherm’ located at lower
altitudes than in the northern Dolomites. The "San Lucano"
glacier was probably one of many tongues derived from the
plateau icecap and was supplemented by snow avalanches
from the deep Agnèr gullies. The valley cross-section has a
flat bottom and steep sides, which indicates glacial widening
and some downcutting. For examples, the furrows excavated
by rivers in the bedrock of Tegnàs at the San Lucano church
are over 200 m deeper than the present floodplain (Caielli and
de Franco 2011; see chapter 1.3.3).
Other examples of glacial erosion forms are the massive
glacial cirque of Angheràz Valley (Fig. 20), suspended circuses (Pian del Miel, Seconda Pala) and roche moutonée
developed in dolomitic rocks (Fig. 21). Accumulation forms
are modest but very significant: Castiglioni (1939) identified a
series of moraines, attributed to the Buhl stage, slightly upstream from Taibon (Torte locality) and the terminal and side
moraine of the Gschnitz stadium in the Angheràz Valley.
Recently, other terminal moraine banks (attributable to Daun
stage) were discovered at around 2,000 m above sea level near
the Tromba di Miel (Fig. 22).
At the Pont locality, outcrops consisting of sandy clay and
dark silt layers with frequent dropstones, have been identified
as lacustrine deposits of a glacial contact lake (Fig. 23),
attributable to the early glacial retreat. Other lacustrine
Fig. 19 a Fragment of leaf
Albertia sp. b Fragment of leaf
Albertia sp
deposits of clay and silty clay were identified by a 50-m
mechanic bore at the Paluc locality, near San Lucano
Church. These clays, covered by fluvial gravel and cobbles,
reveal a dammed lake correlated with buried moraine banks of
the Buhl stage. The permeability of different soils in this area
compared to the innermost part of the valley is also underlined
by the spread of springs (see Tegnas River Geomorphology as
a Morphodynamic Witness).
Gravity-Related Forms
The variety of the landslides has produced an important
example of intrinsic geomorphodiversity at a regional
scale: the complexity of their categories, causes, age,
lithology, motion, extension etc. (Soldati et al. 2004)
make the San Lucano Valley an open laboratory for
worldwide research. Glacial remains, perched on the
north facing slopes, currently generate deformations
within surface discontinuities. Gravity is the most important morphogenetic action, since the disappearance of
the glaciers, due to the exceptional gradients of the
slopes. Massive mudslides (debris flow) are widespread
in the Angheràz Valley and Van de Mez, where a
continuous detrital aquifer, consisting of coalescing alluvial fans and deposits of landslide surrounds both
sides of San Lucano Valley. Large postglacial landslides
came from slopes and collapsed towards the valley. The
Geoheritage
Fig. 20 a Northward view of
Cima Pape and Lastia di
Gardes, taken from the top end
of Angheràz Valley. In the
foreground of the picture are
visible a landslide debris and a
debris flow, the small wooded
hill in the picture centre is a
moraine embankment of the
Gschnitz stage
largest, located below the Pale dei Balcoi (Fig. 3)
(Castiglioni 1939; Zampieri 1987), is probably a deep
gravitational slope deformation. Observing the morphology of the southern slopes below the Agnèr together
with the fracturing of rocks (Fig. 4), it can be assumed
that similar phenomena have also affected the slope in
front of Lagunàz and Borselle localities. The rubble of
the landslide is mostly buried beneath the alluvial cover
which is very deep in this area, as the ice overexcavation exceeds 200 m. Another extensive landslide
deposit is found in the Reiane Valley volcanics of Pian
de la Stua area. The best known landslide is the rockfall
of Pra Lagunaz, which detached in 1908 from the Cime
di Van del Pez (where unstable masses are still observable) (Doglioni and Bosellini 1987; Doglioni 1987,
Fig. 21 The Fradusta Glacier
on the Pale plateau, seen from
Cime dei Vanidiei. On the left a
glacial circle suspended
bordered by a fault scarp (Pian
del Miel); on the right a
suspended glacial valley (Val
Reiane). The action of LGM
glaciers is recognisable from
erosion ("montonatura") of
dolomite rocks
1992, 2007; Castellarin et al. 1996; Zattin et al. 2008;
Stefani et al. 2007).
Revealing Buried Geomorphology Using
Seismostratigraphy and Seismic Tomography
To determine the hidden physical structures of the San Lucano
Valley, two high-resolution seismic lines were executed by the
IDPA-CNR (Milan unit), across the Tegnas stream to
obtaining information on seismostratigraphy, wave propagation speed and the morphology of buried structures (seismic
tomography; Fig. 24). The same data was also interpreted
using a multirefractor method to give an image of discontinuities directly from the seismic sections.
Geoheritage
Fig. 22 Frontal moraine levees
(Daun stage) in Val del Miel
The data generally has a good signal/noise ratio and the
sections obtained are shown in Fig. 25. The final seismic
section on line 1 (Fig. 25a) reveals the reconstruction of
buried structures to a depth of about 200 m. The reflectivity
characteristics of the seismic basement and sedimentary
cover found in glacial-type valleys are described in a previous paper by de Franco et al. (2009).
From the top to the bottom of each section, observe
the presence of three seismic units can be observed, the
most superficial of which is characterised by a P-wave
velocity up to 1,700 m/s and reaching a maximum
depth of about 60 m comprises recent sediments saturated by water. Below, there is a second seismic unit
characterised by P-wave velocity greater than 2,500 m/s.
This layer is made up of compact sediments 100–110 m
in depth, but decreasing northwards and southwards and
reaching, respectively, depths of 30 and 40 m. A third
Fig. 23 Clayey-sandy silts with glacio-lacustrine dropstone near Pont site
unit of maximum thickness and at the maximum depth
of approximately 200 m southward, showed velocities
of over 3,200 m/s and may comprise portions of collapsed basement. The final seismic section obtained
along the line 2 (Fig. 25b) shows similar characteristics
to those described for line 1.
The images obtained show the presence of a refractor at a
depth of approximately 60 m which further deepens southward; this discontinuity may be interpreted as a boundary
between the more recent (i.e. post glacial) unconsolidated
alluvial deposits and the underlying compacted fluvial–glacial deposits.
The processing of seismic data acquired in the San
Lucano Valley provides: (1) an 'echo' image from subsurface
reflection points, (2) the velocity of compressional seismic
waves and (3) the refractor image.
The interpretation of the images has allowed the
reconstruction of both the geometry of the main refractors of recent deposits and the geometry of the bedrock.
It also suggests the presence of multiple depositional
sequences and a maximum depth of a few hundred
metres (up to 250 m). Integration of results with the
geology, structural geology, surface geomorphology and
geostratigraphy allows the characterisation of the physical valley structure (geometrical and geo-mechanical
parameters) and the reconstruction of the seismic stratigraphy of the sedimentary cover and seismic basement
and the location of buried morphological structures. For
both lines (Fig. 25) we can hypothesise a depositionalcentre migration from south to north, probably due to
both superficial and deep gravitational collapse that
moved northward during the alluvial process. Positions
of an older depositional-centre can also be identified,
respectively at a depth of 60, 135 and 240 m.
Geoheritage
Fig. 24 Above, two images of San Lucano Valley: orthophotomap
(left) and eastward view of the 3D model (right), showing two seismic
lines (line1, A–A1 and line2, B–B1) and their location in respect to San
Lucano Church and to the knickpoint. - Below, the arrows indicate the
two seismic lines on two topographic sections cutting the valley in
NNE-SSE direction
Tegnas River Geomorphology as a Morphodynamic Witness
confining a drainage network of 167 km (approximately
46 km2) across a catchment area confined between the two
vertical walls of the Pale di San Lucano and Agnèr Mount. In
the westernmost part of the valley (see Fig. 31) two fourth
order tributaries collect rainfall from a 29-km2 watershed. One
of them, the upper Tegnas, flows northward through the
Angheràz Valley while the other (Bordina stream) flows
southward, converging at 850 m above sea level (Col di Pra
locality) and giving rise to the main fifth order Tegnas stream.
The San Lucano Valley is a tributary of the main Cordevole
Valley (Belluno). It retains a clear glacial imprint and its
average entrenchment is nearly 2 km deep, having crossed
the nucleus of the largest cliff of Belluno Dolomites (where
carbonate and detrital sedimentary rocks are intimately associated with intrusive and extrusive igneous rocks). The watershed rises to an elevation of over 3,000 m above sea level,
Fig. 25 Final stack section obtained along line 1 a and line 2 b after static corrections, converted to depth. The lines show limits of identified units
Geoheritage
Fig. 28 Tegnas stream view: San Lucano Church is located over a
knickpoint where a buried dam causes a thick gravel upstream
deposition
Fig. 26 Fluvial terraces of Tegnas River upstream from the San
Lucano Church. Above an old streambed; below the highest level is a
relict of 1966 event floodplain
This stream runs eastward, mostly on flat land with less than
2 % of slope, interrupted by a few rapid steps for 4 km until the
San Lucano church (750 m above sea level). The slope
Fig. 27 Tegnas stream near Col
di Pra' village. Thalweg
changes observed and mapped
between Bordina creek
confluence and the path to
Cozzolino Refuge, from the last
35 years
steadily increases until the stream meets the Cordevole River
at 610 m above sea level after 3 km.
The land use in the San Lucano Valley is not intensive
and there has not been interference to the riparian zone since
the flood of 1966, during which the majority of the existing
trees (mainly conifers) were uprooted. After the flood of
1966, an exceptional riparian forests of Alnus incana and
Geoheritage
Fig. 29 Tegnas, upstream
stream-type sequence,
classified by RSC method.
Stream reaches are located
between Bordina creek
confluence and San Lucano
Church: after an initial
erosional occurrence (F4),
riverbed is aggrading (D4) until
the knickpoint. (C4 view is
downward, all others are
upward)
Fraxinus excelsior with some Mountain Maple and Spruce
took over. These forests are of high natural interest for the
European Community (site BL28 from Natura 2000 network in ARPAV 2001) and the area is now conserved and
constantly monitored. For these reasons, the lower Tegnas
river has become an open laboratory to study the stream and
how it adjusts to both past and recent morphodynamic
events. The geomorphology of this stream is also evidence
of channel changes over a 50-year period (Figs. 26 and 27).
These geomorphological processes are reflected in the
changes of the stream (Rosgen 2003; Powell et al. 2004;
Testa and Aldighieri 2011). By observing fluvial geometry,
such as bankfull stage indicators (Leopold et al.1964), riverbed entrenchment and sinuosity, changes in granulometry
along the stream, riverbed slope, aggradation or erosion
processes, changes in the type of stream can be tracked
(Harrelson et al. 1994). Following the Rosgen Stream
Classification (RSC) (Rosgen 1994, 1996), these authors
identified two main stream behaviours upstream and downstream from San Lucano Church (Figs. 28 and 31). The
church is located near to the river, where the valley bottom
is filled with 200 m of fluvial deposits due to a waterproof
septum (see Glacial Landscape). This septum comprises a
buried moraine (Castiglioni 1939; Giordano 2011) which is
probably overlain by a collapsed deep landslide (Caielli and
de Franco 2011), generating a natural break point in the
longitudinal profile of the stream: a "knickpoint". This
knickpoint underlines the sudden change of the hydraulic
regime and along few hundreds of metres the following can
be observed:
Upstream, a meandering sequence of unstable F4 and
stable B4 and C4 stream-type channels, as described by
Rosgen (2001, 2003, 2006) (Fig. 29) digresses and
moves an amount of sand and gravel material unexpected for the discharge and watershed size, to an aggrading
D4 stream type and makes a large and deep (more than
200 m) gravel deposit (lake sediments were found in a
drill).
Downstream, a steep B2 stream-type, probably of
relatively recent age, entrenches its bed with flow controlled by the gravel reservoir and increased spring-time
water. The stream then progresses to a more confined
channel morphology (G-type and F-type) (Fig. 30) carving its alluvial fan until it reaches the Cordevole river.
With the current climatic conditions, only centennial
floods will probably be able to reach the highest natural
banks (Fig. 30—B2), which, therefore, remain as “relicts” of past hydro-climatic conditions.
Fig. 30 Tegnas, downstream stream-type sequence, classified by RSC
method. Stream reaches are flowing downstream from San Lucano
Church to the Taibon village: starting from a bedrock controlled reach
(B2) the riverbed is more and more entrenched, depositional processes
are quite absent (B3) until the confluence with Cordevole river. (B3
view is downward, all others are upward)
Geoheritage
Fig. 31 Orthophotomap of San
Lucano Valley watershed:
location (points, lines and
areas) of geomorphosites listed
in Table 4 and main toponyms
Enhancing the San Lucano Valley Geoheritage
Geomorphosites Assessment
Introduced by Panizza in 2001, the term "geomorphosite"
shows the “characteristics of the landscape with particular
and significant geomorphic attributes that qualifies the same
as part of the cultural heritage of a territory" (Panizza and
Piacente 2003). The San Lucano Valley shows an assortment
of notable geomorphological features and an abundance of
geomorphological and geological features that constitute an
inheritance of global significance (Fig. 31). Among these,
karst features such as karren-type fields (rillenkarren,
rinnenkarren, trittkarren and kamenitza) are distributed on
the reef slope surface of the Pale dei Balcoi and in Pian di
Miel. Sinkholes are also frequent in the Pale di San Lucano,
the Pale di S. Martino plateau and along the fault of Coston
della Vena (about 20 m deep). There are also several karst
springs, among which the best known is the Livinàl
dell’Acqua, which flows with more than 100 l/s, and two
Table 1 Score values assigned
to each parameter
The “null” value can be assigned
only to Z
Observations
S
D
A (% of total area)
R
C
E
Z
curious rock arches, the Besanel arch at the top of Boral de
Lagunàz and "El Cor" on the Pale dei Balcoi, characterised by
an unusual heart shape. A complete set of interesting sites,
already known in literature (Bertini 2011), was taken into
consideration for the assessment of their “scientific quality”
index (Q), by using the Coratza and Giusti (2005) method, as
reported in Panizza (2005).
In the previous sections, three geomorphosites of remarkable significance regarding the geologic, palaeoclimatic and
morphodynamic evolution of the valley were comprehensively explained: the first is the Ladinian dolomite/limestone
outcrop (Figs. 13 and 14), the second the Anisian fossil plants
deposit (Figs. 16, 17 and 18), and the third is the knickpoint of
the Tegnas river near to San Lucano Church (Fig. 28). In this
section we assess a Q value for them, so as to calibrate the
effectiveness of the cited method (Coratza and Giusti 2005).
To obtain the quantitative assessment, each geomorphosites
has been assigned to a category according to the Carton et al.
(2005) outline: Area (e.g. moraine deposit, glacial circus etc.),
Line (e.g. stream or river, waterfall, gully etc.) and Point (e.g.
Score=0
Score=0.25
Score=0.50
Score=0.75
Score=1
No value
Low
Low
<25
Several
Bad
Occulted
Poor value
Medium
Medium
25–50 %
Medium
Medium
Partially occ.
Medium value
High
High
50–90 %
Few
Good
Easy to see
Important v.
Very high
Very high
90–100
Unique
Very good
Well exposed
Essential v.
Geoheritage
Table 2 Detailed score values assigned to each one of the test geomorphosites
Knickpoint
S
D
A
R
C
E
Z
SUM
Fossil plant of agordo FM
Dolomitisation outcrop
Score
Weight
Q
Q_norm
Score
Weight
Q
Q_norm
Score
Weight
Q
Q_norm
0.25
0.75
0.25
1
0.75
0.5
0.5
4
0.75
0.75
0.5
1
0.75
1
1
0.19
0.56
0.13
1.00
0.56
0.50
0.50
3.44
0.03
0.08
0.02
0.14
0.08
0.07
0.07
0.49
1
0.5
0.25
1
0.5
0.5
0.25
4
0.75
0.75
0.5
1
0.75
1
1
0.75
0.38
0.13
1.00
0.38
0.50
0.25
3.38
0.11
0.05
0.02
0.14
0.05
0.07
0.04
0.48
1
1
0.25
1
0.75
1
0
5
0.75
0.75
0.5
1
0.75
1
1
0.75
0.75
0.13
1.00
0.56
1.00
0.00
4.19
0.11
0.11
0.02
0.14
0.08
0.14
0.00
0.60
Bold items are the parameters expressed by the formula in the text
E: Evaluation of the site’s exposure. To determine the
level of visibility or presence of anthropic elements
which impede direct access.
Z: The importance of the geosite is not exclusively
in relation to its geological content but also a
consequence of its ecological, historical and/or touristic values.
erratic boulder, tower, small cave etc.). Coratza and Giusti
(2005) have suggested that the letter Q should be attributed to
the sum of the parameters (capital letters) that experts on and
or observers of the area denote according to the following
formula:
Q ¼ sS þ dD þ aA þ rR þ cC þ eE þ zZ
Where: S=“scientific research”, D="didactics", A="area" (total area of geomorphosite), R="rarity" of similar
geomorphosites in the same area, C="state of preservation",
E="exposure" and Z="added value".
Furthermore, the computation of Q is finalised by multiplying each score to its corresponding weight (lower case).
In our case the assigned weights are: s=0.75; d=0.75; a=
0.5; r = 1; c = 0.75; e = 1 and z = 1. An assessment score
(Table 1) to each of the above parameters is attributed
following the criteria resumed below:
S: This factor cannot be null, otherwise the geosite
cannot be considered. Particular importance is given
to this parameter so, as to attribute a high “S” score,
i.e. numerous publications and research projects are
necessary.
D: The geological processes in the site must be
expressed as evident and of exceptional importance.
A: Area of geosite divided by the total area of similar
types of geosite. It is important to be aware of the
extension as the bigger the geosite is, the higher its
score will be.
R: Rarity with respect to other nearby geosites. In this
case the rarity of the geosite is compared to those
nearby; the geological must be unique within a certain
study area and work scale.
C: The preservation level of the site is evaluated to
detect if the initial integral status has been modified
due to of natural factors (e.g. weathering), anthropic
actions (e.g. buildings) or acts of vandalism.
Therefore, to express the scientific importance of the
geomorphosite so as to be able to compare the results with
others assessed with different methodologies, the sum (Q) of
the scores is normalised between 0 and 1 following the
formula:
Q norm ¼ Q=Q maxðin this case Q max ¼ 7Þ
The computational procedure of the Q value for all three
tested geomorphosites is displayed in Table 2.
Finally, the ultimate value of a geomorphosite is
obtained by adding to the Scientific Value “Q” an
Additional Value, assigned following the indicators
Table 3 Description of the “additional-values” added to Q for the
assessment of the ultimate geomorphosite value
Additional value
Description
NR
ME
DE
PE
EV
SHV
MV
PV
SCV
PRV
CRV
SEV
Nature rarity
Model of evolution
Training example
Paleoenvironmental highlights
Ecological value
Historical–scientific value
Mineralogical value
Paleontological value
Scenic value
Prehistoric value
Religious cultural value
Socio economic value
Geoheritage
Table 4 Geomorphosites of San Lucano Valley, ranked by decreasing value of scientific quality (Q)
Label
Geomorphosite name
Type
Scientific quality/value (Q)
Additional value
1
Pizèt
Point
4.56
ME, DE, DHV, SCV, CRV
49
Dolomitisation outcrop
Point
4.19
NR, ME, DE, PE, SHV
2
Brecce Pónt, Cave Marmo Nero
Area
4.19
SHV, CRV, SEV
3
Cascata di Pónt
Line
4.06
ED, DE, SCV
4
Forcella Gardès
Area
4.06
DE, PE, ME
5
Circo Testata Valle Angheràz
Area
4.00
ME, DE, PE, SCV
6
Parete Nord Dell'Agnér
Line
4.00
NR, EV, SCV
7
Frana Prà E Lagunàz
Area
3.94
SHV, CRV
8
Deposito di Pónt
Point
3.88
NR, ME, PE
9
Cascata Dell'Inferno
Line
3.81
DE, PE, SCV
10
Pian di Mièl
Area
3.81
ME, DE, SCV
11
Sill di Malgonera
Area
3.75
NR, DE
12
Van Del Pez
Area
3.56
NR, DE
13
Livinal Dell'Acqua–La Sfèsa
Point
3.56
DE
14
Morene Stadiali Valle Angheràz
Area
3.50
ME, DE, PE
15
Le Peschiere–Lago
Area
3.50
PE, DE, ME, SEV, SCV
16
Frana Postglaciale di Péden
Area
3.50
PE
17
Campanile Della Besàuzega
Point
3.44
DE, SCV
48
Knickpoint
Point
3.44
NR, ME, DE, SHV
19
Forcella Cesurette
Area
3.44
PE, SHV, MV, SCV, PRV, SEV
18
Fossil plants of Agordo FM.
Point
3.38
DE, PE, SHV, PV
20
Conglomerato Interglaciale
Point
3.38
NR, PE
21
L'Anfiteatro Seconda Pala San Lucano
Area
3.38
DE, PE, EV, SCV
22
Campo Boaro
Area
3.38
DE, EV, MV, SCV
23
Piano Inclinato
Area
3.25
DE, SCV
25
Cascata Val Reiane
Line
3.19
DE
26
Faglia Bordina
Line
3.19
DE
24
Crepe Rosse
Line
3.06
DE, ME
27
Le Peschiere–Masarèi De Le Tòrte
Area
3.00
ME, DE PE
28
Tromba di Mièl
Point
3.00
NR, DE, SCV
29
Circhi Sommitali Pale San Lucano
Area
2.94
ME, DE, PE, SCV
30
Grotta San Lucano
Point
2.81
DE, SHV, CRV
31
Sass Da Le Cròss
Point
2.81
SHV, CRV
32
Boral di San Lucano
Line
2.81
DE, SCV
33
Torre Armena
Line
2.81
DE, SCV
34
Valón De Le Scàndole
Line
2.81
DE
35
Alveo Epigenetico Bordina
Line
2.81
NR, ME, PE
36
La Ghiacciaia
Point
2.75
NR, DE
37
El Cor
Point
2.56
NR, DE, ME, SCV
38
Boral De La Besàuzega
Line
2.56
DE
39
Boral di Lagunàz
Line
2.56
DE, SCV
40
La Scudèla
Area
2.56
DE, PE
41
Corn Del Bus
Point
2.56
DE, SCV
42
Covol Mont
Point
2.31
ME
43
Arco Del Bersanel
Point
2.31
ME
44
Cól De L'Usèrta
Point
2.19
SHV
45
Pòles
Point
2.13
NR, ME, SCV
46
Sorgenti di San Lucano
Point
2.06
ME
47
Roa Del Forn
Line
1.94
PE
Bold items are the test geomorphosites of Table 2
Geoheritage
expressed in Table 3. This added information does not
modify the Q value, but gives a further qualitative contribution to the site description.
Discussion and Limits
This study has considered the various parameters
according to a census of the geomorphosites, evaluating
the connection between their heritage importance, the
surrounding landscape and its use. “The Scientific
Quality of the site is only a numeric indicator, subject
to variation according to the observers judgment and
general characteristics of the studied area” (Coratza
and Giusti 2005).
The scores have been given following the guidelines
of Avanzini et al. (2005), which have been modified
according to the requirements of the San Lucano Valley.
The result is the list of Table 4: the highest Q values
correspond to a site (Pizet) that is strongly connected to
the local community history (quarry activities, landslides). The test site of Dolomite outcrop came in second place. The excursion itineraries and touristically
important landmarks also obtained a high score.
Geological, ecological or geomorphological elements
have an intermediate value of Q (peat bog, knickpoint,
faults, fossils, glacial moraines) irrespective of their
scientific importance. Low marks are given to the “peculiarities” which are part of either collective imagination (El Cor, la Scudela, la Ghiacciaia and Roa del
Forn) and/or ecological–technical properties (San
Lucano springs).
The principal limit with this method is tied to the influence of the operator’s personal experiences. Another limitation stems from the attribution of the so-called weighting
that does not follow a clear and univocal line of thought. In
this case, the weighting has been assigned according to the
geological and geomorphological characteristics of the area
with the purpose of enhancing the San Lucano Valley
geoheritage in a geotouristic context and the values, therefore, are high especially with regards to “rarity”, “exposure”
and “added value”, but this result can be reached in other
ways.
Final Considerations
The San Lucano Valley is already well known for its natural
attractions. This paper has documented the abundance and
assortment of geological and geomorphological sites of the
area as witnesses of a 200 million years old history, and how
these elements are still preserved and also show the most
recent landscape evolution. Furthermore, attempting to apply a pre-existing analysis and classification, the current
authors employed a method that, notwithstanding its limitations, enabled the application of the scores, ranging from
0 to 1, to a set of geomorphosites, in order to enhance their
importance from the geotouristic perspective.
This study, therefore, classifies the San Lucano Valley as
an important inheritance of global significance and as a
unique geomorphosite within the Dolomites area. Indeed,
in 2009 this valley, together with other dolomitic groups,
was included in the UNESCO program and the scientific
importance of this area could, therefore, be promoted as
follows: informative boards along the valley, touristinformation points, publication of geotouristic guides and
maps and other modern forms of communication (i.e.
through web facilities, GIS, WebGIS and Apps for mobile
devices).
This promotion could be achieved with collaboration
between local authorities, official governmental authorities,
territorial administrations, non-profit organisations, together
with research institutions. As predicted by Desio in 1947, it
can be confirmed that the leading role of local geology
experts is an important key for the widespread of the geological culture.
Acknowledgements Many thanks go to all the authors who
attended the Agordo symposium together with the chairman of
the conference Eng. Luciano Sabbedotti, who helped with the
initial preparation of these notes. Many thanks also go to the
colleagues of ARPAV (Belluno) who worked in the field and to
many local people and undergraduate students that worked hard to
develop public awareness. Valuable acknowledgements to the reviewers Prof. Mario Panizza, Prof. José Brilha and an anonymous
reviewer who provided a substantial contribution to the final
version of this manuscript.
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