Hypogenic caves of Sicily (Southern Italy)

Full text

HYPOGENIC CAVES OF SICILY (SOUTHERN ITALY)
Marco Vattano1, Philippe Audra2, Fabrizio Benvenuto3, Jean-Yves Bigot4, Jo De Waele3, Ermanno Galli5,
Giuliana Madonia1, Jean-Claude Nobécourt6
1Department of Earth and Sea Sciences, University of Palermo, Via Archirafi 22, 90123 Palermo, Italy,
marco.vattano@unipa.it, giuliana.madonia@unipa.it
2Polytech’Nice-Sophia, Engineering School of Nice – Sophia Antipolis University, & I’CiTy (IMREDD), 930 route des
Colles, 06903 Sophia-Antipolis, France, audra@unice.fr
3Department of Biological, Geological and Environmental Sciences, Bologna University, Via Zamboni 67, 40126
Bologna, Italy, fabrizio.benvenuto2@studio.unibo.it; jo.dewaele@unibo.it
4Association Française de Karstologie (AFK), 21 rue des Hospices, 34090 Montpellier, France,
catherine.arnoux@club-internet.fr
5Department of Earth Sciences, University of Modena and Reggio Emilia, Largo S. Eufemia 19, 41121 Modena, Italy,
gallier@unimore.it
6CRESPE, Le Hameau de l’Ara, 259 Bd Reine Jeanne, 06140 Vence, France, jcnobecourt@free.fr
First results of a study on hypogenic caves in Sicily are presented. Inactive water-table sulphuric acid caves and 3D maze
caves linked to rising of thermal waters rich in H2S were recognized. Cave patterns are guided by structural planes, medium
and small scale morphological features are due mainly to condensation-corrosion processes. Calcite and gypsum represent
the most common cave minerals. Different types of phosphates linked to the presence of large bat guano deposits were
analyzed.
1. Introduction
Hypogenic caves are recognised as generated by water
recharging from below independently of seepage from the
overlying or immediately adjacent surface. Waters are often
thermal and/or enriched in dissolved gases, the most
common are CO2and H2S. Hypogenic caves can be thermal
caves, sulphuric acid caves, and basal injection caves. They
differ from epigenic caves in many ways, such as:
speleogenetic mechanisms, morphological features,
chemical deposits, and lack of alluvial sediments
(Klimchouk 2007; Klimchouk and Ford 2009; Palmer 2011).
Several studies were conducted to evaluate the hypogenic
origin of a large number of caves (Klimchouk and Ford
2009; Stafford et al. 2009; Audra et al. 2010; Plan et al.
2012; Tisato et al. 2012). A significant contribution was
given by the work of Klimchouk (2007) that systematically
provided instruments and models to better understand and
well define the hypogenic karst processes and landforms.
Studies on hypogenic caves in Italy were carried out since
the 90s in different karst systems, especially in the central
and southern Appenines. These studies mainly concerned
chemical deposits related to sulphuric ascending water and
micro-biological action (Galdenzi and Menichetti 1995;
Galdenzi 1997; Piccini 2000; Galdenzi and Maruoka 2003;
Forti and Mocchiutti 2004; Galdenzi 2012; Tisato et al.
2012).
This paper aims to describe preliminary the first results of
a study conducted in some hypogenic caves in Sicily,
highlighting their main features such as pattern,
morphology, mineralogy and speleogenesis. These are
Monte Inici karst system and Acqua Fitusa Cave. For this
purpose topographic and geomorphological surveys were
carried out, and about 40 samples of cave minerals were
taken in different parts of the caves. In addition, a brief
description of Monte Kronio karst system is given. It
represents one of the most important hypogenic karst
systems of Sicily, characterized by flows of hot air and
vapor rising from below.
2. Karst in Sicily
Karst in Sicily is widespread and exhibits a great variety of
surface and underground landforms related to the wide
distribution of soluble rocks (Di Maggio et al. 2012). About
20% (more than 6,000 km2) of the land area consists of
carbonates and evaporites, primarily gypsum (Fig. 1).
Carbonate karst lies mainly in the northwestern and central
sectors of the Apennine chain and the foreland area in
southeastern Sicily; gypsum karst occurs chiefly in the central
and southern areas of the island, though evaporite landscapes
are also present in the northern and western parts of Sicily.
Carbonate and gypsum karst systems develop under
unconfined conditions and in most cases constitute
epigenetic systems fed by meteoric waters. Hypogene caves
are located only in carbonate rocks and are linked to the
presence of deep thermal waters.
Figure 1. Gypsum (white) and carbonate karst areas (grey) and
localization of investigated hypogenic karst systems. 1. Monte
Inici; 2. Acqua Fitusa. 3. Monte Kronio.
Karst and Caves in Carbonate Rocks, Salt and Gypsum – oral 2013 ICS Proceedings
144

3. Hypogenic caves
3.1. Acqua Fitusa Cave
Acqua Fitusa Cave opens in the eastern section of the Sicani
Mounts (west-central Sicily), along the north-eastern fault
scarp of a N-S anticline, westward vergent, forming the Mt.
La Montagnola (Fig. 1). The cave formed in the Upper
Cretaceous Rudist breccias member of the Crisanti Fm.,
composed of conglomerates and reworked calcarenites with
rudist fragments and benthic foraminifera (Catalano et
al. 2011).
At present it is inactive with a thermal spring occurring
300 m north and 30 m below the cave. The waters have a
temperature of about 25 °C, and are indicated as chlorine-
sulphate alkaline (Grassa et al. 2006 and references therein).
During the spring-summer-early autumn the cavity hosts a
large colony of bats, including Myotis myotis and
Miniopterus schreibersii species (Mucedda pers. comm.),
that produce significant amounts of guano.
The first explorations of Acqua Fitusa were carried out in
the early XXth century by some inhabitants of the
neighboring villages, but the first human frequentations of
the cavity have to go back to the Paleolithic and
Chalcolithic periods, as evidenced by the discovery of
numerous lithic fragments, remains of food and burials
(Bianchini and Gambassini 1973). Lombardo et al. in 2007
gave a description of the cave and some studies concerned
the hydrogeochemistry and isotopic composition of the
nearby spring waters (Grassa et al. 2006 and references
therein).
According to the survey made in 2011, the cave consists in
at least three stories of subhorizontal conduits, displaying
a total length of 700 m, and a vertical range of 25 m
(Fig. 2). The main passages are generally low and narrow
and follow sets of joints oriented in ENE-WSW, E-W and
N-S directions. Very small passages develop from these
galleries making incipient mazes.
The conduits breach the fault scarp in more points at
different heights. The main entrance leads to a large
chamber enlarged both by corrosion and breakdown
processes, connected to an upper subhorizontal passage that
likely formed during a past higher karst base level.
Acqua Fitusa Cave represents a clear example of inactive
water table sulphuric acid cave (Audra et al. 2009). Despite
the small size, the cave is very interesting for the abundance
and variety of morphologies and deposits formed at and
above the water table where H2S degassing and thermal
convection produced strong condensation-corrosion
processes.
The floor of some passages is breached for several meters
by an inactive thermo-sulphuric discharge slot that can
reach a depth of 7 m (Fig. 3). In some sections of the caves,
notches with flat roof, linked to lateral corrosion of a water
table with concentrated sulphuric acid, carve the walls at
different heights, recording past stages of base-level change.
Several forms of small and large sizes, generated by
condensation-corrosion processes above the water table, can
be observed along the ceiling and walls. Ceiling cupolas
and large wall convection niches occur in the largest rooms
of the cave. Here and in the upper gallery, pendants at
junctions of more cupolas or between braided channels are
widespread. Cave walls of many passages are carved at
different heights by deep wall convection niches that in
places form notches (Fig. 3). Condensation-corrosion
channels similar to ceiling-half tubes carve the roof of some
passages; replacements pockets due to corrosion-
substitution processes are widespread; boxwork created by
differential condensation-corrosion were observed in the
upper parts of the conduits.
Figure 2. Acqua Fitusa Cave: plan view and extended profile
(Survey: Ceresia, Inzerillo, Provenzano, Sausa, Scrima and
Vattano, 2011).
Figure 3. Acqua Fitusa. Passage with discharge slot at the floor
and different levels of wall convection niches.
The most abundant cave mineral is gypsum which displays
different shapes and colours. Replacement gypsum crusts
are common in many passages; the gypsum is located in
large vertical fissures along the walls, it can partially cover
wall convection notches, or replacement pockets. A gypsum
body of about 50 cm of thickness was found on the floor of
the biggest room in correspondence of which small ceiling
cupolas and pendants are associated on the roof.
Centimeter-sized euhedral gypsum crystals grew inside
mud sediments. Finally, the walls of a feeding fissure are
covered with a network of gypsum “roots” in which the
Karst and Caves in Carbonate Rocks, Salt and Gypsum – oral 2013 ICS Proceedings
145

3.2.1. Abisso dei Cocci
Abisso dei Cocci is an inactive 3D maze cave formed in
Lower Jurassic limestones and dolomitic limestones (Inici
Fm.), arranged in decimetric westward dipping beds. The
cave is one of the largest of Sicily, reaching a total length
of over 2,053 m and a vertical range of -300/+61m. It
consists of several stories of large subhorizontal galleries
and chambers connected by deep shafts. In plan view the
galleries are mainly oriented in NW-SE and NE-SW
direction, parallel with the main tectonic discontinuity lines.
Some conduits are gently inclined and follow the dip of
bedding planes, whereas the shafts develop along vertical
fissures or fault planes. Passages display sub-circular cross-
sections, sometimes with vadose entrenchments (Fig. 5).
Several features linked to rising thermal water and air flow
were recognized in many sections of the cave. Many
passages are characterized by large convection wall niches,
mega-scallops, ceiling cupolas, and ceiling spheres. In some
cases adjacent passages are separated by partitions (Fig. 5).
The cave lacks alluvial sediments; on the other hand
chemical deposits are abundant mainly in the middle level
of the cave, where dripping is still active. Here, a large
variety of calcite speleothems, such as stalactites,
stalagmites, flowstones, shelfstones, etc., occur. Calcite is
present also in the shape of powder, thin crusts, and
frostwork. Gypsum was recognized in the middle and
deepest sections of the cave in the form of tabular or
acicular colourless small crystals (Fig. 5).
biological control is obvious. Further investigation on these
apparently subaqueous gypsum speleothems is still
ongoing.
Phosphate minerals, such as apatite [Ca5(PO4)3(OH)], were
found in the form of thin crusts near large deposits of bat
guano.
3.2. Monte Inici Complex
Monte Inici karst system is situated in northwestern Sicily
(Fig. 1), in the eastern sector of the Trapani Mountains, and
opens along the southeastern slope of Mt. Inici, a gently
westward – dipping monoclinal relief affected by NW-SE,
NE-SW and NNW-SSE high angle faults. The karst system
is composed of two caves, Grotta dell‘Eremita (or Grotta
del Cavallo) and Abisso dei Cocci, formed in Jurassic
limestones and dolomitic limestones. Thermal waters
emerge from three hot springs east and at lower altitude
respect to the caves (Fig. 4). These are of chloride-sulphate
alkaline-earth type and have a temperature respectively of
48.3 °C (Gorga 1), 49.6 °C (Gorga 2), and 44.2 °C (Terme
Segestane) (Grassa et al. 2006 and references therein).
The caves preserve clear signs of prehistoric and medieval
human presence, such as several lithic and bone fragments,
food remains, ceramic finds typical of the Middle Neolithic-
Middle Chalcolithic (Grotta dell’Eremita), and large
amounts of medieval pottery (XIth–XVth century), identified
mainly within Abisso dei Cocci (Tusa 2004). These caves
were explored and described in the early 90s. On the basis
of morphological features a genesis linked to thermal waters
was supposed (Biancone 1993; Messana 1994).
Figure 4. Sketch of Monte Inici karst system and localization of
the thermal zone.
Figure 5. Abisso dei Cocci. Passages displaying sub-circular cross-
section with vadose entrenchment characterised by uncovered
ceiling and walls with cupolas and gypsum in the lower parts.
Different types of phosphate minerals were found in several
parts of the caves. Hydroxylapatite occurs as thin crusts or
powder above the bedrock, and even forms true stalactites.
Crandallite [CaAl3(PO4)2 (OH)5•H2O] is present as soft
white grains at the contact between weathered rock and bat
guano, in association with green small spherical masses of
montgomeryite [Ca4MgAl4(PO4)6(OH)4•12H2O].
Phosphates are linked to the presence of large fossil bat
guano deposits occurring in many parts of the cave.
3.2.2. Grotta dell’Eremita
Grotta dell’Eremita formed in Middle-Upper Jurassic
reddish-gray limestones with ammonites (Buccheri Fm.),
and in Lower Jurassic limestones and dolomitic limestones
(Inici Fm.) in its deepest parts. The cave is a relict 3D maze
cave, which reaches a total length of 2880 m, and a vertical
range of -306 m. The air temperature, measured in
Karst and Caves in Carbonate Rocks, Salt and Gypsum – oral 2013 ICS Proceedings
146

December 2011, was 17.6 °C in the passages near the
entrance area, gradually increasing up to 21.0 °C in deepest
chamber of the cave.
Grotta dell‘Eremita shows many morphological and
depositional features similar to Abisso dei Cocci, although
some differences were recognized. The cave is made up of
large subhorizontal passages and big chambers connected
by deep shafts, which are guided by the main tectonic
discontinuity planes. Some galleries are gently inclined
following the dip of bedding planes and display sub-circular
cross-sections. Along the walls of these passages, in
correspondence of the bedding planes, several small
conduits filled by well-cemented fine reddish sediment of
continental nature, are visible. Large convection niches,
mega-scallops, ceiling cupolas, ceiling spheres, and drip
holes are widespread in the chambers and in the largest
passages of the cavity (Fig. 6).
A breccia consisting of decimetric carbonatic clasts in a
reddish silt matrix characterized by thin laminas and
decantation structures is exposed at walls and ceiling of
some deep passages.
Different chemical deposits were identified: besides calcite,
occurring in the form of white cigar-shaped crystals grown
under old bat guano, reddish laminae, or coralloids, gypsum
was found as tabular or fibrous crystals. Phosphate
minerals, such as hydroxylapatite and taranakite, occur
mainly in form of powders or crusts near or above deposits
of bat guano. Carbonate-apatite was recognised as crusts or
small stalagmites (Messana 1994). As in Abisso dei Cocci
clastic sediments are absent.
3.3. Monte Kronio karst system
Monte Kronio karst system opens in the southern scarp of
Mt. Kronio or Mt. San Calogero, north-east of Sciacca town
(southern Sicily) (Fig. 1). Mt. Kronio consists of an
imbricate fan system linked to ENE-striking, closely spaced
imbricate thrust sheets, involving Triassic to Miocene
platform and pelagic platform carbonate deposits (Monaco
et al. 1996). The karst system is made up of a series of
cavities characterized by rising of hot air and vapour flow
at temperature of about 38 °C, connected to the presence of
thermal waters. These waters, emerging along the southern
slope of Mt. Kronio at lower altitude respect to the cave
entrances, are of chloride-sulphate alkaline type and have a
temperature ranging between 32 and 55 °C (Grassa et al.
2006 and references therein; Capaccioni et al. 2011).
Actually they are used for aesthetic and therapeutic
purposes.
The caves were visited by man since the end of the
Mesolithic for residential use, place of worship, necropolis,
and from the Ist century BC for thermal purposes. The first
attempts to explore the caves date back to the end of the
XVIIth century; since the 40s several exploration campaigns
conducted by the Commission Grotte “E. Boegan” of
Trieste identified and surveyed the cave system nowadays
known. The explorations, carried out with great difficulty,
due to the critical environmental conditions with
temperatures of about 38 °C and humidity of 100%, have
allowed the discovery of an extended maze cave system
about 200 m deep (Perotti 1994).
The system is composed of more cavities, located at
different altitude, characterized by subhorizontal passages
connected by deep shafts or steep passages, but there is not
always a passable connection between the several branches
of the caves. Some galleries breach the southern scarp of
Mt. Kronio through small openings some of which emit hot
air, other ones aspire cold air from outside (Perotti 1994).
The upper section of the system, known also as Stufe di San
Calogero, consists of a series of chambers separated by
man-made walls, connected to a maze of narrow passages.
Some chambers are characterized by hot vapour flow rising
from a deep shaft which connects these passages with two
large hot galleries, oriented in NW-SE direction, where
abundant archeological finds were discovered. A small cave
(Grotta del Lebbroso), interested by rising of hot vapour
flow, develops eastward at the same altitude, but to date no
passable connection to the rest of the system was
recognized. The deepest part of the cave is represented by
a large and deep shaft (Pozzo Trieste), from which more
levels of narrow passages, both hot and cold, develop
breaching the southern cliff of Mt. Kronio (Fig. 7). A large
breakdown deposit occurs at the bottom of the shaft.
Walls and ceiling of the caves are weathered and important
gypsum deposits, in form of powders or crusts, were
observed (Perotti 1994).
Figure 6. Grotta dell’Eremita. Passage along a bedding plane
where filled protoconduits are visible. Walls and ceiling are
characterised by large convection niches and cupolas.
Figure 7. Monte Kronio. Forms linked to condensation-corrosion
(on the right); weathered flat roof affected by condensation (on
the left).
Karst and Caves in Carbonate Rocks, Salt and Gypsum – oral 2013 ICS Proceedings
147

4. Discussion and Conclusions
The study of the geological setting, cave pattern, medium
and small scale morphological features, and the analysis of
cave minerals allowed defining a hypogenic genesis for the
investigated karst systems. All the caves developed along
structural planes, such as bedding, fracture or fault planes,
whose enlargement is due to corrosion by H2S-rich thermal
waters, and to condensation-corrosion processes by air flow
in the cave atmosphere.
Acqua Fitusa cave is an inactive water-table sulphuric acid
cave linked to corrosion processes of carbonate rock with
replacement of gypsum by H2S-rich thermal water (Fig. 8).
Occurrence of notches with flat roof indicates lateral
corrosion processes by sulphuric thermal water fed through
discharge slots still open on the floor of some passages.
Ceiling cupolas, large wall convection niches,
condensation-corrosion channels, boxwork testify that
enlargement of voids occurred mainly above the water table
where H2S degassing in the cave atmosphere, oxidation of
sulphides and thermal convection produced strong
condensation-corrosion processes. In addition, large
amounts of gypsum, replacement pockets, in places
containing gypsum, suggest the corrosion of the carbonate
rock occurred with replacement of gypsum according to the
sulphuric acid speleogenesis (Galdenzi and Maruoka 2003;
Audra et al. 2010 and references therein). Like other
sulphuric acid systems (Galdenzi and Menichetti 1995) the
different levels of passages record past stages of the water
table, in relation to changes of the base-level.
Grotta dell’Eremita and Abisso dei Cocci caves were
identified as inactive 3D maze caves. Pattern and cross
sections of the main passages of Abisso dei Cocci suggest
the early speleogenetic phases to have occurred in phreatic
conditions by rising thermal water which formed a well
developed 3D maze system. An important role in the
evolution and widening of the subterranean voids was
played by air flow when the cave passages switched from
phreatic to vadose conditions, as a consequence of the uplift
phases of this sector of the Sicilian chain. In this case, the
processes of corrosion by condensation from air flow rich
in H2S, favoured on one hand the enlargement of the early
voids with the formation of large megascallops and ceiling
cupolas, on the other hand the deposition of gypsum in the
lower parts of the passages (Fig. 9).
The first speleogenetic phases in phreatic conditions of
Grotta dell’Eremita are recorded, beside the pattern, by the
presence of several filled anastomosed protoconduits visible
at the bedding plane, along which the passages develop. The
next phase of evolution of the system may have followed
two possible ways: a) enlargement of voids by
condensation-corrosion processes which destroyed the
network of protoconduits and formed the main passages as
testified by the presence of megascallops, ceiling cupolas,
etc. (Fig. 10); b) corrosion processes by a deep sulphuric
thermal water enlarging the early voids, destroying the
protoconduits and forming the main passages in phreatic
Figure 8. Acqua Fitusa. Genetic mechanism of cave passages due
to H2S degassing in the cave atmosphere.
Figure 9. Abisso dei Cocci. Enlargement of passages by widening
of pre-existing forms due to condensation-corrosion.
Figure 10. Grotta dell’Eremita. Genesis of passages along a
bedding plane with formation of protoconduits enlarged by
condensation-corrosion.
Karst and Caves in Carbonate Rocks, Salt and Gypsum – oral 2013 ICS Proceedings
148

conditions. Successively, condensation-corrosion processes
by acid sulphuric air flow enlarged the early phreatic voids
with the formation of megascallops, ceiling cupolas etc.,
and deposition of gypsum. The question is open, future
studies will clarify the issue.
Finally, in all the investigated caves the presence of
different types of phosphate minerals is linked to the large
deposits of bat guano (Hill and Forti 1997).
Monte Kronio system is an active hypogenic karst system
and is unique in Sicily and probably in the world. It owes
its peculiarity to the rising of hot air and vapour flow, linked
to a deep thermal aquifer, still not identified within the
system. Although this system is known since prehistoric
times, yet little is known about its real development and
speleogenetic mechanisms due to the harsh environmental
conditions that make exploration extremely difficult.
Multidisplinary studies are currently in progress.
Acknowledgements
G. Ceresia, S. Inzerillo, A. Provenzano, L. Sausa, A. Scrima
contributed to resurvey Acqua Fitusa cave. G. Ceresia, A.
Provenzano, P. Tordjman and G. Valdese helped sampling.
Mr. Mancuso helped visiting to Monte Inici karst system.
Commissione E. Boegan and La Venta for facilitating the
field activities in the Monte Kronio caves. Michal Philippi
and Jiří Bruthans for the review of this paper.
References
Audra P, D’Antoni-Nobecourt J-C, Bigot J-Y, 2010. Hypogenic
caves in France. Speleogenesis and morphology of the cave
systems. Bulletin de la Société Géologique de France, 181 (4),
327–335.
Audra P, Mocochain L, Bigot J-Y, Nobécourt J-C, 2009. The
pattern of hypogenic caves. Proceedings of the 15th
International Congress of Speleology, Kerrville (TX), 2,
795–800.
Bianchini G, Gambassini P, 1973. Le Grotte dell’Acqua Fitusa
(Agrigento) I – Gli scavi e l’industria litica. Rivista di Scienze
Preistoriche, 28 (1), 1–55.
Biancone V, 1993. Monte Inici. Una sorpresa tutta siciliana!
Speleologia, 29, 72–77.
Capaccioni B, Vaselli O, Tassi F, Santo AP, Huertas AD, 2011.
Hydrogeochemistry of the thermal waters from the Sciacca
Geothermal Field (Sicily, southern Italy). Journal of Hydrology,
396, 292–301.
Catalano R, Agate M, Avellone G, Basilone L, Gasparo Morticelli
M, Gugliotta C, Sulli A, Valenti V, Gibilaro C, Pierini S, 2011.
Walking along a crustal profile across the Sicily Fold and
Thrust Belt. AAPG International Conference & Exhibition,
Post conference field trip 4, 27–29 October 2011.
Di Maggio C, Madonia G, Parise M, Vattano M, 2012. Karst in
Sicily and its conservation. Journal of Cave and Karst Studies,
74(2), 157–172.
Forti P, Mocchiutti A, 2004. Le condizioni ambientali che
permettono l’evoluzione di speleotemi di zolfo in cavità
ipogeniche: nuovi dati dalle grotte di Capo Palinuro (Salerno,
Italia). Le Grotte d’Italia, 4 (5), 39–48.
Galdenzi S, 1997. Initial geological observations in caves
bordering the Sibari plain (southern Italy). Journal of Cave and
Karst Studies, 59 (2), 81–86.
Galdenzi S, 2012. Corrosion of limestone tablets in sulfidic
ground-water: measurements and speleogenetic implications.
International Journal of Speleology, 41 (2), 149–159.
Galdenzi S, Maruoka T, 2003. Gypsum deposits in the Frasassi
Caves, central Italy. Journal of Cave and Karst Studies, 65,
111–125.
Galdenzi S, Menichetti M, 1995. Occurrence of hypogenic caves
in a karst region: examples from central Italy. Environmental
Geology, 26, 39–47.
Grassa F, Capasso G, Favara R, Inguaggiato S, 2006. Chemical
and isotopic composition of waters and dissolved gases in some
thermal springs of Sicily and adjacent volcanic islands, Italy.
Pure and applied geophysics, 163, 781–807.
Hill C, Forti P, 1997. Cave mineral of the world. National
Speleological Society, Huntsville, 463.
Klimchouk AB, 2007. Hypogene Speleogenesis: hydrogeological
and morphogenetic perspective. National Cave and Karst
Research Institute, Special Papers, 1, Carlsbad, NM, 106.
Klimchouk AB, Ford DC (Eds) 2009. Hypogene Speleogenesis
and Karst Hydrogeology of Artesian Basins. Ukrainian Institute
of Speleology and Karstology, Special Paper, 1, Simferopol,
280.
Lombardo G, Sciumè A, Sollano G, Vecchio E, 2007. La Grotta
dell’Acqua Fitusa e l’area della Montagnola nel territorio di
San Giovanni Gemini (Ag). Speleologia Iblea, 12, 125–132.
Messana E, 1994. Il sistema carsico del gruppo montuoso di M.
Inici (Castellammare del Golfo, TP). Bollettino
dell’Accademia Gioenia Scienze Naturali, 27 (348), 547–562.
Monaco C, Mazzoli S, Tortorici L, 1996. Active thrust tectonics
in western Sicily (southern Italy): the 1968 Belice earthquake
sequence. Terra Nova, 8, 372–381.
Palmer AN, 2011. Distinction between epigenic and hypogenic
maze caves. Geomorphology, 134, 9–22.
Perotti G., 1994. Kronio. – Le stufe di San Calogero e il loro flusso
vaporoso. Bollettino dell’Accademia Gioenia Scienze Naturali,
27 (348), 435–475.
Piccini L, 2000. Il carsismo di origine idrotermale del Colle di
Monsummano (Pistoia – Toscana). Le Grotte d’Italia, 1 (5),
33–43.
Plan L, Tschegg C, De Waele J, Spötl C, 2012. Corrosion
morphology and cave wall alteration in an Alpine sulfuric acid
cave (Kraushöhle, Austria). Geomorphology, 169–170, 45–54.
Stafford KW, Land L, Veni G (Eds.) 2009. Advances in Hypogene
Karst Studies. National Cave and Karst Research Institute
Symposium, 1, 182.
Tisato N, Sauro F, Bernasconi SM, Bruijn R, De Waele J, 2012.
Hypogenic contribution to speleogenesis in a predominant
epigenic karst system: A case study from the Venetian Alps,
Italy. Geomorphology, 151–152, 156–163.
Tusa S, 2004. Grotta del Cavallo e la preistoria del comprensorio
di Inici. In: CAI Palermo (Ed.). I Tesori di Monte Inici, 85–95.
Karst and Caves in Carbonate Rocks, Salt and Gypsum – oral 2013 ICS Proceedings
149