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Caves and karstic phenomena

ITAL IAN HAB ITATS

1


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ITAL IAN HAB ITATS

MINISTERO DELL AMBIENTE E DELLA TUTELA DEL TERRITORIO

M U S E O F R I U L A N O D I S T O R I A N A TU R A L E C O M U N E D I U D I N E

Caves and karstic phenomenaLife in the subterranean world

Italian habitats

Italian Ministry of the Environment and Territory Protection / Ministero dellAmbiente e della Tutela del Territorio

Friuli Museum of Natural History / Museo Friulano di Storia Naturale Comune di Udine

Scientific coordinatorsAlessandro Minelli Sandro Ruffo Fabio Stoch

Editorial commiteeAldo Cosentino Alessandro La Posta Carlo Morandini Giuseppe Muscio

Caves and karstic phenomena Life in the subterranean worldedited by Fabio Stoch

Text byMauro Chiesi Luca Lapini Leonardo Latella Giuseppe Muscio Margherita Solari Fabio Stoch

In collaboration with

Paolo Forti Maria Manuela Giovannelli

English translationby

Gabriel Walton

Illustrations by

Roberto Zanellaexcept for 89 (Enrico Zallot) and 90 (Marco Bodon)

Graphic design byFurio Colman

Photographs by

Archivio Circolo Speleologico e Idrologico Friulano 14/2, 40, 41, 49, 50, 56, 60/1, 78Archivio Museo Friulano di Storia Naturale 21, 22, 23Archivio Unione Speleologica Bolognese 11, 12, 17, 27, 28, 29, 30, 43, 45, 47, 54/2, 125/1, 132

Adalberto DAndrea 8, 14/3, 19, 35, 39, 44, 62, 74, 133, 134, 140, 148Sergio Dolce 90Fulvio Gasparo 52, 94, 99, 103/3, 107, 109/2, 116/1

Salvatore Inguscio, 103/1, 103/2Enrico Lana 95, 100, 104, 106, 109/1, 109/3, 118Luca Lapini 54/1, 60/3, 60/4, 122, 123

Leonardo Latella 63, 64, 69, 112/1, 112/3, 113/2, 126Giuseppe Muscio 60/2, 85, 127Tiziano Pascutto 88, 113,/1, 117, 121/2, 125/2

Giuseppe Lucio Pesce 87/1Mauro Rampini 54/3, 112/2Federico Savoia 14/4, 156Pino Sfregola 152

Margherita Solari 14/1Fabio Stoch 54/5, 92, 93, 96, 101, 124, 143Franco Tiralongo 130

Elido Turco 129Stefano Zoia 54/4, 87/2, 105, 108, 111, 114, 116/2, 116/3, 119, 121/1

2002 Museo Friulano di Storia Naturale, Udine, Italy

Even partial reproduction of texts and photographs is forbidden. All rights reserved.ISBN 88 88192 03 4

Cover photo:Cave of Santa Barbara, Sardinia (photo: Unione Speleologico Bolognese)


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Directive 92/43 of the European Community, issued on May 21

1992, and commonly known as the Habitat Directive,

represents a considerable improvement in overall environmental

policy. The innovative approach of the Directive lies in its

recognition of the complex and crucial role played by interactions

between animal species, living plants, and the ecosystem

surrounding them.

It was within the perspective of the Habitat Directive that long-term

activities could be planned and carried out.

In order to inform the general public about the natural history of

Italy and to publicize the results of scientific research, the Italian

Ministry of the Environment and Territory Protection has planned

publications focusing particularly on the environment.

Italian habitats is a series aimed at improving present knowledge

of environments at risk of degradation or even of disappearance -

habitats in which special and noteworthy fauna and floracan be found.

The Ministry appointed the Friuli Museum of Natural History to

prepare this series of monographs, starting with the present volume

on karst phenomena.

The flexible but scientifically correct structure of these volumes

describes Italian habitats of international interest. This important

series, while enhancing common knowledge about the

environment, will contribute towards laying the foundations for

proper management of natural resources - that great heritage

belonging to us all.

Altero MatteoliItalian Minister of the Environment and Territory Protection


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Intoduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Giuseppe Muscio

Karstic phenomena and speleology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Giuseppe Muscio

Biospeleology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Leonardo Latella Fabio Stoch

Taxonomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Fabio Stoch Leonardo Latella Luca Lapini

Protection and conservation of the subterranean environment . . . . . . 131

Mauro Chiesi Luca Lapini Fabio Stoch

Suggestions for teaching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149Margherita Solari

Select bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

ContentsItalian habitats

1

Caves and

karsticphenomena

2

Springs and

springwatercourses

3

Woodlands

of the PoPlain

4

Sand dunes

and beaches

5

Mountain

streams

6

TheMediterranean

maquis

7

Sea cliffs androcky

coastlines

8

Brackishcoastal lakes

9

Mountainpeat-bogs

10

Realms ofsnow and ice

11

Pools,ponds and

marshland

12

Aridmeadows

13

Rocky slopesand screes

14

High-altitudelakes

15

Beechforests of the

Appennines


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IntroductionGIUSEPPE MUSCIO

9

Talking about caves to people who have never visited one is difficult. Once,

during a meeting on cave photography, a discussion arose regarding the best

techniques for the best results, and one well-known cave photographer

reminded those present that a true photograph of a cave is ... completely

black! And it is true: in caves, light is an extraneous element, a real form of

pollution which man brings into the darkest environment imaginable, into a

silence broken only by the dripping of water or the sound of sometimes rapidly

moving waters.

Few places other than caves have inspired mans imagination: in the past, he

used them as dwellings and for protection, but he rarely penetrated further

than light was able to reach - that limit beyond which mystery hovered,

accompanied by fear and superstition.

Caves have also been places of worship or of fortification, but only from the

19th century onwards have they been systematically explored and sc ientifically

studied. Since then, man has understood how very singular the cave

environment is: limited in extent, protected by rock, and with a particularly

stable climate. But for this very reason, he also understood how delicate the

equilibrium of the underground world is, and how easily it can be upset.

Thus, in recent decades, we have realized the importance of respect for and

protection of karstic phenomena. Although it covers the subterranean world,

this type of protection must necessarily start from the surface of the earth,

where karstism is widespread.

The term karstism derives from Carso (Karst), the name of the geographic

area between Italy and Slovenia, which has become synonymous with a

certain type of landscape or, more simply, of everything morphologically linked

with caves. Carso in fact derives from karren, a proto-European term

which simply means rock - grastin Slovene, in use since 1177; krasin Croat,

used since 1230; carsoin Italian, and Karst in German, in which the original

root is clearly preserved. It is not surprising that the root means rock,

because in karstic areas rocks outcrop frequently and are wonderfully

modelled. The landscape is thus characteristic, partly because it is not only

superficial but also, indeed mainly, underground.

The opportunity to increase our knowledge of karstism in Italy in order to

Subterranean lake in Grotta d i Punta Galera (Palinuro, Campania)


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1110 protect it better is fully justified: there are many endemic forms in the

subterranean fauna and interesting minerals which are typical of the

subterranean environment. However, there is also a very simple reason for

protecting it which, alone, is abundantly clear to all: at least 50% of Italian

drinking water is of karstic origin (the percentage is even higher in some

southern areas of the country) and this figure is certainly destined to

increase in the future, due to the various forms of pollution involving the

steadily deeper and deeper watertables of the plains. Equally clear is the

fact that few environments are so vulnerable and so slow to change as the

subterranean one.

Today, the karstic environment is not only intensively explored but is also a

source of scientific information, a reservoir of p rime importance. In the past,

caves were the places of the imagination, the dwellings not only of

prehistoric man but also of mythical beings which populated - and still

populate - folklore.

Thus, we have learned to observe natural cavities in the earth as a highly

variegated source of information. Speleology - the science which studies them -

comes from the Greek spelaion(cave) and logos(study), and now attracts

research-workers from a whole range of fields: geology, mineralogy, biology,

ethnography, archeology, etc., and the speleologist is, basically, a naturalist

in the widest sense of the word. There are many only slightly known, or

completely unknown, aspects of caves, like that of mineralogy: for example,

already in prehistoric times, men used the gypsum from caves in the Tuscan-

Emilian Appennines (e.g., Calindri), and nitrates were exploited even earlier.

More recently, many caves have been completely emptied of t heir contents of

bat d roppings, since the guano, as it is called, is an excellent natural fertilizer.

Speleology came into being as a science in its own right at Trieste in the 19th

century. It was the natural response of a large city which, then in full

expansion, was searching for new water supplies in its hinterland. And its

hinterland was the classic Karst, in which the only river of a certain size, the

Timavo, mainly flows underground. One indication of the amplitude of

speleology in Italy is that there are at least 10,000 speleologists, and more

than 33,000 caves have been explored and surveyed. Although some are

several dozen kilometres long or hundreds of metres deep, very many are

small. But this does not mean that they do not contain very fine natural

beauties.

Natural cavities in the earth are often exploited from the economic viewpoint.

Among the various Italian caves open to the public, four are well-known:

Grotta di Castellana in Puglia (Apulia), Grotta di Frasassi in the Marches,

Grotta Azzurra in Campania, and Grotta Gigante in Friuli-Venezia Giulia, with

hundreds of thousands of visitors every year. On one hand, the caves bring in

local tourist revenue; on the other, the tourists themselves cause many

environmental problems regarding the proper conservation of underground

environments: not just pollution due to the waste they leave or the damage

they do - more simply the disturbance created by the sole presence of man

influences the delicate equilibrium of the subterranean climate (temperature

and humidity).

Writing about karstism is therefore not a simple matter: it is almost impossible

to put down on paper the feelings we experience when we enter a cave and

penetrate its absolute darkness. For a speleologist, whether the cave is long or

short is not important: what counts is the fascination of exploration. There are

only a few very large caves, richly decorated with concretions or concealing

important findings, but no cave lacks its own hidden mystery. The true

passion which urges the speleologist to adventure beneath the earth is

knowledge, the exploration of an underground world which no- one or very few

have ever violated, the desire to study a phenomenon which, perhaps only on

a small scale, is always unique, completely different f rom its surroundings.

Concretions in Grotta di Valdemino (Liguria)


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13

The natural environment which surrounds us, which we observe without

thinking about it, is generally called panorama. When our gaze embraces a

set of characteristics which are all somehow linked, we call it landscape.

Thus, the dry karstic landscape is often compared with one containing

superficial bodies of water of various kinds, because one of the peculiarities of

a karstic area is precisely the absence of any clearly observable surface

water network.

The karstic process is that set of mainly chemical factors which lead to the

dissolution of carbonatic rocks (limestone, dolomia), forming surface cavities

(dolinas) or underground ones (caves), creating a subterranean water network,

and modelling outcropping rocks in a very typical way. However, not all natural

cavities owe their origin to karstism: some, for example, may form in or under

glaciers, or in lava, or be of mixed origin.

There have also been lengthy debates on what effectively constitutes a cave

and what kind of empty space in rock, carbonatic or not, enters this category.

For the Italian Cave Registry, listing natural cavities which have been offic ially

surveyed and described, a cave is a cavity sufficiently large to allow access to

humans and more than five metres long. This restriction is not applicable if we

consider caves as developing morphological elements within which the

widening of a small crack in the rock may lead to a vast subterranean system

which is later perhaps destroyed by collapse or occlusion or, in the long

term, involved in the various processes of erosion to which emerged land is

subject.

The karstic process

Limestone is a rock composed almost entirely of calcium carbonate (CaCO3),

a compound with very low solubility in water. However, in the presence of

carbon dioxide (CO2), the water becomes more aggressive and acid, and

dissolves the calcium carbonate, forming calcium bicarbonate, according to

the following reaction: CaCO3 + H2O + CO2 Ca++ + 2HCO3-. The

equilibrium shifts right or left according to pressure and temperature.

Karstic phenomena and speleologyGIUSEPPE MUSCIO

Extensive karstifiable rocks in Sardinia


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Superficial karst formsExtremely variable in size; the best known arelimestone pavements (also called karren orkarrenfeld), dolinas and solution pans (or kamenitza)

Swallow holesWater reaches the subsoil not only through minutecracks in rock, but also through true natural shafts.These are considerably modelled by the waterwhich passes through them, first creating a circular

cross-section, when water flows under pressureand occupies the entire shaft, and later scouringout part when flow diminishes and water acts onlyon one wall

Collapse depositsAt the bottom of large shafts and in areas ofextreme fracturing, large quantities of collapsedmaterials may accumulate. This phenomenonsometimes leads to the creation of large halls insubterranean karstic systems

Subterranean riversEntire stretches of caves may be occupied bysometimes large watercourses. The walls often

show traces of how the water regime developed,both in the shape of the cross-section and in thepresence of special forms of excavation on thewalls (scallops)

Conduits and siphonsThe lowest parts of karstic systems are typicallyfilled with completely flooded tunnels, calledsiphons. According to the morphology of the area,these siphons may meet in areas in which watergenerally flows freely.

1514 The strict meaning of the term karstic process refers only to the chemical

reaction which affects calcium carbonate and, consequently, only to pure

limestone.

Today, the term has been expanded and karstic phenomena is accepted to

refer to everything regarding the corrosive activity to which carbonates are

subjected (thus, limestone and dolomia) and also to gypsum (calcium

sulphate) and any other solubilizable rock (rock-salt, quartzite).

Although the above reactions are the main causes of the development of

karstism, they are certainly not the only ones and there are many variables

The superficial part of a karstic area is

intensely modelled and shows only a

few traces of watercourses.

The action of water creates structures

like karrenand dolinas.

It then flows into the subsoil through

the network of cracks, some of which

widen to form true shafts,large enough to allow people to

descend them. Through this dense

network, water reaches first the

percolation or vadose zone where, for

example, it drips slowly, or flows as a

thin sheet down whole walls of rock.

Deeper down are those stretches of

the karstic system where water flows

more regularly (galleries with

subterranean streams, waterfalls,

small lakes, etc.) until the so-called

phreatic zone is reached. Still deeper

inside the rock is the water-saturated

area with completely flooded galleries,called conduits under pressure.

A succession of this type is the result

of long, complex evolution of the

territory, in which external factors

intervene, e.g., tectonics, or variations

in water-table levels.

A model cross-section of a karstic area Giuseppe Muscio


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1716 which come into play: from the characteristics of the rocks to the condition of

the vegetal cover, from the local climate to a series of mechanisms

accompanying the main chemical reactions.

Starting from lithotypes, not all limestones, as already mentioned, are pure: as

well as calcite (calcium carbonate), small quantities of various minerals are

always found, in particular dolomite (carbonate of calcium and magnesium),

forming passages between limestone and dolomia. Karstic phenomena may also

develop in these rocks; indeed, a small percentage of magnesium favours them.

Therefore, although waters rich in CO2 can dissolve carbonatic rocks, to

what extent they may do so is difficult to establish. First of all, we must bear in

mind the climatic conditions and in particular the local level of rainfall, since

water is an essential component of the reaction. The quantity of mass which is

removed (rate of ablation) over a certain period of time has been calculated

experimentally, taking into account the fact that karstic corrosion occurs not

only on the surface but above all in the subsoil. Therefore, reported values do

not refer to the removal of superficial carbonate and do not correspond to a

simple lowering of the topographic surface, but to the entire rock mass

which is dissolved, including that below ground. For a mean precipitation

level of 1000-1500 mm/year, mean ablation rates of 50-100 mm/1000 years

may be hypothesized for the Mediterranean area; values for Alpine areas are

slightly higher.

Recent measurements made in Friuli-Venezia Giulia have defined carbonate

erosion rates of 20-40 mm/1000 years. i.e., slightly lower, but they refer only to

outcropping rocks and may thus be compared with those quoted above. This

means that karstism alone, in 10,000 years, can remove the equivalent of one

metre of thickness from an Alpine carbonatic massif. This is a very significant

value; in gypsum, the figure is t en times greater.

If we examine the classic reaction, the presence of CO2 clearly plays an

essential role, since it makes water aggressive towards carbonates. CO2 is

present in the atmosphere, but its quantities may increase considerably in the

soil, according to the vegetal cover, and its solubility is greater in cold ratherthan in warm waters. This means that, other conditions being equal, cold

waters are more aggressive than warm ones; but in hot, humid climates the

production of CO2 due to decomposition of vegetal residues is very high and it

is for this reason that, although the waters are warmer, local condit ions favour

more marked karstic phenomena.

The question of water temperature is important if, for example, we think of

high-altitude karsts, where snow meltwater easily generates superficial

karstic forms - always, of course, if they flow on carbonatic rocks. Grotta Paradiso at Fluminimaggiore (Sardinia)


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1918 It is also clear that, although the role of CO2 is essential to make waters

aggressive, the possible presence of strong acids enhances their corrosive

action, giving rise to what are called hyper-karstic phenomena. Strong acids

may be present in the external environment, but they are more commonly

found in the rocks themselves: for example, H2SO4 is linked to the reaction of

oxidation of pyrite or H2S of deep origin.

But how do meteoric waters enter carbonatic rocks? Rainwater, which is

enriched in carbon dioxide in the atmosphere and soil, reaches the rocky

surface and is already aggressive.

It may corrode the surrounding rocks when long lines of discontinuity meet,

since they are the preferential directions of flow of superficial waters, and it

begins to excavate the rock, f iltering inside it. At the same time, however, the

water becomes saturated in calcium carbonate and cannot continue its

corrosive activity beyond a certain point: other waters then widen cracks

further. We know that theoretical saturation levels may be exceeded by karstic

waters according to conditions of pressure and temperature, and also that

mixing of waters with different chemical characteristics favours the

development of karstic phenomena. With this knowledge, we can reconstruct

the physical elements which are required for the karstic process to begin.

These are:

1. carbonatic rock containing discontinuities (fractures, faults, etc.);

2. water containing dissolved carbon dioxide;

3. differences in altitude, permitting water movement.

The second point has already been analysed. It is clear that water movement

is essential for the development of karstic phenomena and to remove those

fragments which, not soluble by CO2-enriched waters, could fill the cracks

and prevent further speleogenesis (i.e., the formation of natural cavities).

So let us examine further the first point: discontinuities are the natural

consequences of deformational events undergone by the rocks during their

geological history.

The surroundings are thus full of cracks, mainly only a few microns thick andoften not distinguishable on the surface because they have been altered by

modelling, but they are sufficient to allow water to percolate down. In the past,

a theoretical limit to the downflow of waters was believed to exist, due to the

idea that, at a certain depth (500 or 1000 metres), cracks tended to close as a

result of the enormous mass of overlying rock, thus preventing the passage of

water. We now know that enormous quantities of water are found during the

excavation of tunnels, even if they are overlain by thousands of metres of rock

- an example is the Mont Blanc tunnel.

Until now, in examining speleogenesis - that set of processes which create

karstic cavities - we have referred to the fundamental role played by chemical

corrosion. Although this is essential during the first speleogenetic phase - that

is, when the first subterranean conduits form - as they gradually become

larger, erosion also comes into play. This is a purely mechanical action on thepart of the more resistant granules which chemical reactions free from the

carbonatic matrix (commonly fragments of flint, quartz or ferrous minerals) and

which swirling waters scour against the rock, abrading it.

As karstic conduits progressively widen, collapses favour the formation of

large halls at points in which rock fracturing is especially intense, often at the

point where lines of tectonic origin meet. Research undertaken during recent

decades has definitely changed the original view of the fathers of karstism,

who were, in a certain sense, purists. We now know that there are so many

Grotta Nuova at Villanova (Friuli)


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polje, and are often used for agriculture because of their very fertile soil, with a

superficial, seasonal, water network. In Puglia (Apulia), the word Pulo is used

for similar shapes: e.g., the Pulo of Altamura and that of Molfetta.

Special shapes are due to considerable superficial dissolution which, freeing

blocks of limestone which may become isolated from each other, are often

modelled into strange shapes and aspects, the so-called cities of stone.

Among the superficial forms are springs, either free-flowing (in which water

CATEGORIA FORME PICCOLE FORME MEDIE FORME GRANDI

ACCUMULATION SOLUTION PANS

OVERLAND FLOW KARREN SUBSIDENCE DOLINAS CLOSED VALLEYS

IN FILTRATION C AVERNOU S K ARREN DOL IN AS, SN OW SHAFTSPERCOLATION SHAFTS

CREVASSES CORRIDORS KARSTIC VALLEYS, UVALA

OUTFLOW KARST SPRINGS POLJE BLIND VALLEYS, POLJE

KARSTIC LAKES

CATEGORY SMALL FORMS MEDIUM-SIZED FORMS LARGE FORMS

2120 variables which enter into play in the origin and development of a karstic

cavity, that they certainly cannot be reduced to the simple formula: water +

carbon dioxide + calcium carbonate: although everything starts from a simple

corrosive reaction, all kinds of morphogenetic agents are at work.

Superficial karstic forms

Karstism almost always begins on the surface, i.e., in outcropping rocks,

leading to what is defined as a karstic landscape, composed of highly

differentiated forms according to the various features of the outcropping

lithotype, and the local climate, with particular reference to rainfall: we thus

speak of tropical karst, temperate karst, and so on. Forms are also

generally grouped according to size.

In Italy, karstic zones occupy more than 27% of the entire territory and there

are widespread high-altitude and temperate karst areas, including, for

example, the area between Venezia Giulia and Slovenia, which is part of the

so-called classic karst.

The superficial forms are grouped into categories partly according to size (the

original term is often based on German or Slovenian words; see table, page 21).

Ponds form where rainwater collects in small depressions; overland flow may

give rise to karren, solution flutes or rills, and solution runnels, distributed

according to the gradient of the outcrop.

Dolinas may have various origins and shapes: they are large areas where the

original terrain sank, due to dissolution or collapse. They are circular or

elliptical in shape, and range from a few metres to several dozen metres

across. Larger forms, sometimes several kilometres in diameter, are called

Two types of dolina evolution Surface karst landforms due to impact and streaming of raindrops


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2322 comes from a partially well aerated natural cavity) and those of Vaucluse

type (in which the whole cross-section of the natural cavity is occupied by

water). Then there are karstic lakes , similar in shape to classic lakes but lying

on karstifiable rocks, with mainly subterranean supply. One of the best-known

example is the lake of Doberd in the Karst near the river Isonzo.

Subterranean karstic forms

The ideal cross-section of an already evolved karstic territory may be

subdivided into: an outcropping belt, containing all superficial morphologies

and lacking permanent bodies of water; and the immediately underlying

section, which has a series of shafts and galleries of karstic origin, where

water is present only sporadically after rain.

Further down (vadose zone) are karstic systems with water and, lower still,

near what is called the p iezometric surface, all the cavities in the rock are filled

with water (saturated or phreatic zone).

The modelling action of water in a karstic subsoil creates forms which are

commonly subdivided into karstic conduits and wall forms.

interlayer cavity

runnels

pool

pool

grooves

karstic hole

large runnels

Karst springs: free-flow ing water (left) and Vaucluse type (right) Lake of Doberd (Isonzo Karst): one of the best classic examples of a karstic lake

Names of some common karst forms on rock

Superficial karst forms: small meander, solution pans, grooving


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2524

Dolinas are typical superficial karst

forms found in temperate climates. A

dolina is defined as a closed hollow,

between a few metres and 1 km in

diameter, and composing a simple

hydrographic unit.

The perimeter is generally circular or

subelliptical, although there are alsoirregular or complex forms resulting from

the fusion of a variable number of

dolinas (uvala).

According to the ratio between mean

diameter and depth, dolinas are

classified into three categories: flat,

when the ratio exceeds 2; funnel-

shaped, when it is less than 2; and deep,

when the depth is greater than the

diameter and the slopes are subvertical.

Dolinas are generated by normal

dissolution phenomena by fast-flowing

water moving towards a topographically

depressed point, leaching and corrodingthe rocky slopes. The central point is

often absorbent, due to microcracks in

the rock or swallow holes, not always

visible because they are covered by

debris or soil which, steadily deepening,

makes up the bottom of the dolina.

Superficial dissolution also occurs under

the soil cover and is due to normal

solution, but it may also be related to

periodic variations in the concentration

of carbon dioxide produced by the

biological activity of micro-organisms or

vegetation. At depth, the effects of

corrosion due to mixing of waters,

cooling, or enrichment in magnesium

prevail.

The soil on the bottom of a dolina is

often residual, the result of accumulated

insoluble minerals which compensate

the basic pH in soils deriving from

carbonatic rocks.

Dolinas which developed according to

this model (normal solution) are often

hemispheric or funnel-shaped, and may

occur both in limestone and in rocks

with various degrees of solubility

(dolomitic limestone, etc .). They may

also form in coherent non-soluble rocks

like sandstone and, if they rest on

soluble materials subject to karstism,may cause the collapse or subsidence of

underlying formations.

Very different is the evolution of collapse

dolinas, which have subvertical slopes

and originate from the fallen ceilings of

caves: in this case, dissolution is a factor

of secondary importance.

Although the topographic position of a

dolina may be random, it often reflects

the presence of lithological or tectonic

structures, such as the dip of rock layers

or the directions of faults. Morphology

too (e.g., perimeter lengthening) may be

correlated with these factors.Large dolinas, with diameters exceeding

100 metres, may have their own micro-

climates, with thermal inversions

accompanying inverse stratification of

vegetation and the presence of more

markedly cold-loving plant species.

The micro-climate of a dolina is due to

several factors. In the first place, cooling

by radiation on a concave surface is

greater than on a corresponding flat

area, being directly proportional to the

surface exposed. On the bottom, the soil

is usually saturated in water and

evaporation causes further cooling. In

addition, in autumn and winter, from the

first slope to enter shadow (the western

one) cold air descends towards the

bottom and lowers the temperature in

the hollow even before sunset;

conversely, in the morning, it is reached

by the sun much later than the south-

facing slope. The consequence of these

factors, partially attenuated during

summer, is a strong average thermal

gradient - about 7per 100 metres of

depth, i.e., about 12 times greater than

the external gradient in temperate

climates. This means that, temperature-

wise, descending 50 metres into a dolina

is equivalent to climbing a hill 600

metres high. In these conditions of

microthermy on the cooler southern

slope (exposed to the north), the

resulting vegetation may be a mixture of

local species which prefer cool

environments, or ones generally typical

of higher altitudes.

In this case, the four slopes of the dolina

are covered with different plant

associations, having intermediate

conditions on the western and eastern

slopes and extreme ones on the

northern and southern ones. These

differences are also evident when the

gradient of the slopes are symmetrical,

and depend only on topography: this is

called climatic continentalization.

In very large dolinas, the inversely

stratified vegetation is very c lear and

particularly interesting: in some cases, a

complete series of plant associations

may be found, typical of gradually higher

altitude belts until we come to cenoses

with dwarf pine typical of high-mountain

and sub-Alpine belts.

The peculiarities of dolinas thus

represent an element of discontinuity

which is not only morphological: they

introduce diversity and enrichment into

the environment by means of the

selective organization of flora into

different types of vegetation.

Dolinas

beech

ice

Oriental spruce

dwarf pine willow rhododendron Alpine f lora

silver fir

1100

1050

1000

1150

Seriation of vegetation in a steep dolina in the Italian Karst. Section illustrates phenomenon ofinverse vegetation in relation to microclimates occurring inside cavity

Margherita Solari


14/41

2726 Karstic conduits are created by the chemical action of water along

discontinuities: at the beginning of speleogenesis, the conduits are completely

filled with water under pressure and may later develop into vadose conduits in

which water f lows freely, with a consequent increase in its mechanical action.

Vertical shafts are forms created by percolation. Water also models the walls

of karstic conduits, e.g., in scalloped forms.

Subterranean karstic systems are thus composed of galleries and shafts,

sometimes filled with water (act ive) or abandoned (fossils). However, these

two terms seem to be inappropriate, because the same system often has both

active and inactive parts, or parts which are active during periods of intense

rainfall and not active during the normal water regime.

One particular aspect of speleogenesis in karstic areas is due to hydrothermal

fluids, which are highly corrosive, favouring the formation of large halls, the

development of which is often not influenced by cracks.

In any case, speleogenesis requires lengthy periods of time - in the karstic

environment, from hundreds of thousands to millions of years. Evolution is

more rapid if hyper-karstic or thermal factors intervene; even more rapid is

erosion of gypsum deposits; the filling-in of some caves in the Emilia-

Romagna Appennines has been dated, and only lasted about 5,000 years.

The whole karstic phenomenon of the Gessi del Bolognese is believed to havedeveloped over the last 100,000 years, and most of the caves are less than

18,000 years old.

Non-karstic cavities

Not all natural cavities are due to true karstism: there are some caves of a

certain importance which open inside conglomerates and which may be very

large indeed. This happens because waters act by dissolving the carbonate

which cements conglomerates, thus freeing pebbles and matrix, which are

then removed by mechanical action. These caves often contain thick deposits

of clay and, being subjected to frequent collapses, change their shaperelatively rapidly. Among the most interesting are the caves in the Miocene

conglomerates of Montello (Veneto), some of which are more than 1 km long

(the Busa di Castel Sotterra extends fo r nearly 7 km).

Some caves which develop at the contact between different lithotypes are

considered of mixed origin: there are many which originate at the interface

between carbonate and flysch. The first speleogenetic phase is due to

corrosion of carbonatic rocks, but then the cave expands due to strong

erosion of the flyschoid complex (composed of alternating marl, sandstone

Lava conduit on flanks of Mount Etna (Sicily)

and clay). Caves of this type have been studied in detail in Friuli: the complex

of the Grotta Nuova di Villanova, more than 7 km long, develops precisely at

the contact between a conglomeratic bank (in which both clasts and matrix

and cement are all composed of calcium carbonate and thus the lithotype

behaves, from a chemical viewpoint, like limestone) and Eocene flysch.

Other types of mixed cave are sea grottoes. Their terminal portions, having

originated from mixtures of salt and karstic waters, have often been widened

by the destructive force of the sea.Instead, very far from any kind of karstic origin are caves resulting from lava

flows: widespread mainly around Mount Etna in Sicily, they also occur in other

Italian regions. These caves are called syngenetic, since they usually form over

very short periods of time (from a few days to a few weeks), together with the

rocks which contain them. They are also highly unstable and often do not last

long, being rapidly destroyed if their ceilings collapse. However, it is relatively

easy to date them, when the age of the various lava flows is precisely known.

There are several morphologies, due to both type of lava and mode of


15/41

2928

formation, but the Etna lava caves are grouped into two large categories:

rheogenetic (superficial), and of f racture type. Rheogenetic caves are simply

the empty spaces left by the flow of magma in lava tunnels. They are generated

by liquid lava flowing on a solid surface: the upper part, in contact with the air,

cools and solidifies quite rapidly, while the part underneath continues to flow,

and then leaves an empty space once the supply of lava ceases.

Fracture caves extend in depth along discontinuities sometimes created by

seismic events. Intermediate or mixed forms may also exist, created by a

combination of the two types.

Although it may appear strange, as regards their genesis, lava caves are similarto glacier caves, which also form as a result of flow. In glacier caves, water from

melted ice excavates galleries and shafts, often extremely short- lived.

Climate in subterranean environments

The problem of subterranean climates is of ten underestimated. However, if we

consider to what extent it influences, for example, the fauna living in this

particular environment or, from another viewpoint, the fact that caves were

once extensively used as places in which to preserve food, we realize that this

is not simply a secondary aspect of speleology.

The first point to examine is temperature: in general, apart from the first few

yards of a cave from its entrance inwards, which is influenced by the external

climate, the temperature deep inside is the same throughout the year and is

very close to the mean value of the temperature in the area where the cave

itself is located. This is because fluids (water and air) circulate in caves, and

they determine the temperature. If we base our calculations on the thermal

gradient of the earth, we should have an increase of about 3C for every 100

metres of depth (values measured during the excavation of mine shafts, for

example) but, apart from very small variations, vertical caves such as shafts

maintain their temperature even at depth. For example, in the depths of the

high-altitude carsi (i.e., in carbonatic massifs at altitudes exceeding 1500-

2000 metres), the temperature is generally close to zero, since the caves were

created mainly by the snow meltwater which flows through them.

Due to their isothermy, caves are thus relatively warm in winter and cool in

summer. In low- altitude areas, temperatures range from about 10C in the pre-

Alpine belt to 16-18C in caves in Sardinia or Puglia (Apulia).

There are, of course, special cases like those of lava caves, which have their

own special climatic conditions, with very high temperatures if they have beenrecently formed. But temperature differences do exist in karstic caves, due to

the temperature of their subterranean rivers, the waters of which may come

from several places.

More constant than the temperature

inside natural caves is relative

humidity, ranging from 95 to 100%.

Lower values are only found near the

entrances and in particularly dry

climates.

Air currents inside karstic systems are

of considerable interest. They areusually quite slow, but may be

significant if the cave has several

entrances or ot her kinds of links with

the external world. Currents depend

on season since, as mentioned

above, the temperature of the air in

caves is lower than the outside

temperature in summer and higher in

Ice concretions. Grotta della Spipola(Emilia-Romagna). Swellings indicate mom entsof relatively higher temperature (shortly aftermidday) when ice starts to melt and thenfreezes again

Grotta della Spipola, in gypsum near Bologna (Emilia-Romagna)


16/41

Waters in caves always contain mineral

salts. When they flow inside a cave,

they may become oversaturated and

give rise to chemical deposits.

These deposits have always been

divided into two subgroups:

concretions and mineralizations, the

difference essentially being based onthe d egree of crystallinity: high in

mineralizations and low in concretions.

In fact, in nature there are many

macrocrystalline or even

monocrystalline concretions, just as

there are cryptocrystalline or definitely

amorphous mineralizations: in practice,

the possibilities are infinite. Thus,

although subdivision based on the

degree of crystallinity is not

scientifically valid, it is useful for better

understanding of the various aspects of

the phenomenon.

One particular type of cave deposit isthe result of accumulations of bat

droppings, called guano, used in the

past thanks to its excellent properties

as a fertilizer. It plays a significant role

in the subterranean ecosystem and

may sometimes even influence the

genesis of certain minerals (e.g.,

brushite).

Concretions

This term was once given to deposits of

calcium carbonate, but was then

extended to gypsum.

Then, as mineralogical knowledge o f

the subterranean world expanded, it

was discovered that many other

minerals could give rise to concretions

which were absolutely identical in form

and evolutionary mechanism to those

of calcium carbonate: in Italy, for

example, there are many well-known

concretions of sulphur.

Although several factors may concur to

modify the form and external aspect of

cave deposits, water movement

undoubtedly most greatly influences

their external aspect, so that the most

logical classification of concretions is

based on this parameter.

Concretions resulting

from water movement:

slow dripping:

stalactites, tubular forms,

draperies and curtains

dripping by impact:

stalagmites, conulites,

splash concretions, circles

water flow:

encrustations, columns, b arriers,

moonmilk

submersion:pisolites, cave clouds, coralloids,

moonmilk

capillarity:

eccentric and disc-shaped forms

evaporation:

floating crystals, coralloids, trays

condensation:

rims, boxwork, oriented coralloids,

moonmilk

salient:

geysermites

The first group contains the most

common and numerous concretions,

which is why they are further divided

into two subgroups: the effect of the

gentle detachment of a drop of water is

very different from that of its imp act on

a surface below, and gives rise to very

different forms.

3130 winter. Draughts may be felt inside

underground systems, particularly

when they blow through narrow

galleries from one part of the cave

to another.

Another great difference between

the inside of a cave and the

outside is the composition of the

atmosphere: inside a cave it is

highly variable, while outside it is

much more constant.

What changes significantly is the

amount of CO2 which, in ordinary air,

is normally between 1 and 3%,

whereas inside a cave it may be up

to 100 times greater. These values,

which are due to biological activity in

the soil and water transport, vary

according to season and type of

cave development, but they are inany case within our tolerance range.

Only rates exceeding 10% of CO2are dangerous: they are found in the

lowest layers of some volcanic

caves or ones in which hydrothermal

fluids are present (the phenomenon

was known even in the 18th century

in the Grotta del Cane at Pozzuoli,

near Naples).

Breathing problems arise in some

caves which are, or were, affectedby sulphur exhalations: examples

are the Grotta Azzurra and Grotta di

Cala Fetente at Palinuro (Campania)

and Grotta del Dragone at Maratea

(Basilicata).

For instance, sulphobacteria present

in water greatly reduce the contents

of the oxygen in favour of other

Cave deposits Paolo Forti Giuseppe Muscio

Eccentric concretions of aragonite and calcite

Concretions of barite

Concretion of sulphur and gypsum flakes


17/41

Mineralizations

About a hundred years ago, known

secondary cave minerals numbered less

than 45, for two main reasons: except for

calcite, aragonite and gypsum, which

alone make up more than 99.5% of all

cave deposits, other secondary minerals

are very rare, scattered, and difficult toobserve. However, they now number more

than 260 and new ones are found every

year. By cave mineral we mean a

secondary mineral which formed in a cave

and resulted from a chemico-physical

reaction which involved one or more

primary minerals existing in the rock or in

physical and/or biological deposits inside

the cave itself.

These rigorous limitations are necessary

to avoid secondary cave minerals being

considered together with all minerals

existing in nature. Caves are not generally

environments particularly favourable tominerogenesis, and very many caves do

not contain any secondary minerals at all.

But they may contain a large variety of

rocks: limestone, dolomia, gypsum, rock-

salt, quartzite, basalt, etc.. Their chemico-

physical degradation brings to the system

a large number of ions which may be

deposited as secondary mineralizations.

In addition, speleogenetic evolution may

cause primary mineralizations to outcrop

on cave walls which, in contact with

percolating waters or atmospheric

oxygen, may give rise to new chemical

compounds. Lastly, caves may contain

deposits of clay, guano, bones, etc.,

which in turn bring in ions which produce

further secondary minerals.

On this great variety of substrates, waters

of various origins - meteoric, marine,

thermal - with very different contents of

dissolved salts, in terms of both quality

and quantity, then act on this great variety

of substrates. In special cases, it may not

even be water which acts directly, but

other fluids, such as fumarole fluids in

volcanic environments.

The complexity of substrates and the

variability of water chemistry, combined

with the great differences in temperature

which may exist in caves, give rise to alarge number of phenomena and

potentially active minerogenetic

mechanisms. Some of these act in all

types of caves and over a wide

temperature range; others are only active

in special types of caves or need

particular temperatures in order to

become active. So it is not surprising that

many minerals were observed for the first

time in cave environments. Just one

example is that of francoanellite, a

phosphate found for the first time in the

cave of Castellana and named after the

famous Italian speleologist Franco Anelli.Nine minerals are still today exclusive to

the cave environment.

The scientific importance of cave

deposits

Of all cave sediments, chemical ones and

in particular concretions of calcium

carbonate are highly flexible and powerful

instruments for paleo-environmental and

paleoclimatic reconstructions. This is

because, as they grow, they incorporate

various trace minerals, fragments

transported in suspension during floods,

dust carried in by air currents, and organic

material, varying from molecules of humic

acids to spores and pollens. The laminate

and necessarily ordered structure of

concretions immediately provides a

relative chronological reconstruction of

the events corresponding to each single

growth band. Then there are a series of

methods which, more or less easily,

furnish an absolute chronological scale.

Thus, by analysing in detail the evolutionof stalagmites, we can gain information on

large-scale earthquakes over the last

500,000-600,000 years, and improve our

assessments of seismic risk. Data on the

deposition temperature of concretions

and on t he conditions and mechanisms of

their formation can lead to detailed

paleoclimatic and paleo-environmental

reconstructions, providing much

information on how climates evolved and,

for example, what the landscape must

have looked like in the second half of the

Quaternary era. For instance, thanks to

concretions in coastal grottoes (both

emerging from the water and submerged)

around Palinuro (province of Salerno,

southern Italy), we can date the variations

in sea level in that sector of the Tyrrhenian

Sea over the last few thousands of years.

Thanks to measurement stations located

in caves, we can quantify movements

connected with neotectonic phenomena.

A flowing water

B dripping waterC capillary waterD water in solution pansE water forming by condensationF warm rising water

1 flowstone

2 draperies, curtains

3 column

4 drop stalactite

5 hollow stalagmite

6 curved stalactites7 moonmilk8 disc-shaped forms9 macrocrystalline eccentric forms

10 inflorescences11 microgours12 pisolites13 boxwork14 rims15 geysermites16 rounded concretions17 encrustations18 mud stalagmites19 large crystals

3332

12

3

4

5

67

9

814

10

15

12

11

16

1718

19

13

B

B

E

C

F

D

B

A

A

Paolo Forti Giuseppe MuscioCave deposits


18/41

34

compounds (mainly H2S): while there are no problems in areas well connected

with the outside world, with good air supply, special attention must be paid

further inside.

Neglecting this phenomenon has cost the lives of more than one speleo-diver.

Karstic areas and the major subterranean systems in Italy

Italy occupies a prominent position both in the field of cave study and in more

purely exploratory activity. This is for historical reasons, and because karstic

phenomena are so widespread in Italy: 27% of the territory is composed ofkarstifiable rocks, and well st ructured and highly developed research on caves

has been going on for more than a hundred years. The various regional

registries list more than 33,000 caves, which is a somewhat low percentage of

those actually present in Italy: for example, the cave registry of Friuli-Venezia

Giulia contains more than 6,300 caves over an area of about 7,800 sq.km., and

every year this number increases by about 200 new entries.

There are as many as 180 subterranean systems in Italy (1999 data) which

exceed a depth of 300 metres, and of these six even exceed the threshold of

A

C D E

B

6C

20C

4C

2C

18C16

C

Grotta del Dragone at Maratea (Basilicata)

Air circulation in natural c aves: wind tunn el in summer (A) and winter (B); cold (C) or warm (D) airtrapped; in caves with only one opening, air circulation depends on atmospheric pressure (E)

35


19/41

36 1000 metres. The record depth is that of the Abisso Paolo Roversi in the

Apuan Alps, which goes down as far as -1250 metres.

There are 92 caves (again, 1999 data) which exceed 3 km in length, of which

20 exceed 10 km. The longest Italian cave is the Corchia Complex (Apuan

Alps), more than 52 km long. This is quite a feat, but it pales when compared

with the length of the largest underground system in the world, the Mammoth

Flint Cave in the United States, with more than 500 km of galleries!

Comparing tables of the longest and deepest caves with cave registry entries,

we see that Friuli-Venezia Giulia and Veneto, which have 9% of karstifiableterritory, have more than one-third of known caves, and the same regions,

together with Tuscany, Piedmont and Lombardy, contain three-quarters of all

large Italian caves. These are the most important karstic areas (but it is also

true to say that they have been systematically studied for longer, and have

thus given rise to a greater quantity of data).

Piedmont and Val dAosta. The Val dAosta is almost totally composed of

metamorphic and magmatic rocks, so that it does not contain any karstic

phenomena of significance. However, Piedmont has some of the largest

karstic systems in Italy, mainly concentrated in two large areas of the Maritime

Alps, Marguareis and Mongioie.The Piaggia Bella complex opens in the Marguareis valley, and contains about

a dozen different caves which, taken together, form a subterranean network of

more than 35 km, reaching -950 m. Slightly further south is Labassa, a

downvalley continuation of Piaggia Bella, more than 14 km long and with a

maximum depth of -609 m. In the same massif, the Conca delle Carsene

complex extends for 13.5 km and reaches -759 m. The Abisso dei Perdus,

Abisso Scarasson, Abisso Cuore di Pietra, Abisso Libero, Abisso Ferragosto

and the Colle dei Signori Complex (partly in Italy and partly in France) all

exceed 500 m in depth.

In the Mongioie massif are the C1-Regioso complex (more than 6 km) and the

Grotta delle Vene (4.7 km). The Abisso Ngoro-Ngoro and Abisso M16 in ValCorsaglia both exceed -470 m. The Risorgente della Mottera has been

explored to a depth exceeding 600 m (14 km), almost as far as the karst

surface basin.

The largest cave open to tourists, near Cuneo in Piedmont, is the Grotta di

Bossea, also equipped as a scientific laboratory and well-known for its

remains of the cave bear Ursus spelaeus. The Grotta dei Dossi, near Mondov,

was one of the first Italian caves opened to tourists, being equipped to allow

them to visit in the early 19th century.

TO

AO

MI

GE

TS

TN

VE

BO

FI

AN

AQ

CB

PG

ROMA

NA

BA

PZ

RCPA

CA

Main karstic areas in Italy

LIMESTONE

AND DO LOMIAGYPSUM LAVA

37


20/41

3938 Lombardy. Under the plateau of Cariadeghe (Brescia) is one of the most

important karstic cave phenomena, the largest of which is the Omber en

banda al Bus del Zel, more than 15 km long and about 420 m deep.

The Bergamo mountains contain many karstic areas of great interest: the

Grotta Maddalena in Val Taleggio is about 10 km long.

From the exploratory viewpoint, of considerable potential are the caves

around Lake Como: the Tacchi-Zelbio complex at Piani del Tivano extends for

almost 10 km and the cave at Capanna Stoppani more than 8 km; the Bl-

Guglielmo complex reaches -557 m.The Grigne mountain group contains some of the deepest caves in Italy:

speleologists have descended the Abisso Viva le Donne to -1170 m and the

Abisso Capitan Paff to -795 m.

Almost at the border with Piedmont, near Varese, the Parco di Campo dei Fiori

is another karstic area of great potential: the Nuovi Orizzonti and Marelli caves

extend for almost 6 km, and the Abisso Schiaparelli goes down to -600 m.

Some karstic phenomena in the region were visited by illustrious personages

in ancient times: the intermittent spring of Torno (Como) was described by

Pliny the Elder in 50 A.D., and the cave of Fiumelatte and the Ghiacciaia di

Moncodeno (Como) were described by Leonardo da Vinci. The Ghiacciaia

(ice-box) was again described in minute detail by the Danish polymathStensen in 1627, in a letter addressed to Nicol Cosimo III, Grand Duke of

Tuscany.

Trentino-Alto Adige (South Tyrol). For geological reasons, the largest caves

are to be found in the southernmost area of the region. Although this territory

was the cradle of mountaineering, after much research around the 1930s,

karstic phenomena were only properly studied after the 1960s. One of the

largest Italian caves, Bigonda, is in the Trentino region, and runs for about 26

km in Valsugana, collecting the waters of the Asiago plateau, where the Grotta

del Calgeron (5.3 km) also opens.

Again in Valsugana are the still active complexes of Fosca and CastelloTesino. There are about 700 caves in the Brenta Dolomites and the adjacent

Gazza-Paganella group, including the Grotta di Collalto (5.2 km), Torrione di

Vallesinella, Abisso Popov, and Abisso di Lamar. In Val Daone, south of the

Adamello group, is the Aladino cave (7 km), and the Abisso di Val Parol (1.6

km, -430 m) opens in the northern slopes of Monte Baldo. Superficial

karstic phenomena are marked and widespread in the low Sarca valley and

on Mt. Baldo.

Lastly, explored only during the last 20 years are the karstic phenomena of the

Alto Adige (South Tyrol). Some very long caves have been explored in the

Marebbe plateau in the north-west of the region. Of great importance are the

remains of bears in the Grotta delle Conturines in the high Val Badia.

Veneto. With more than 6,500 registered caves, the Veneto is one of the Italian

regions in which karstism is not only extensive but also best studied. Apart

from small sectors in which magmatic or metamorphic rocks outcrop, the

entire mountain belt, made up of mainly carbonatic rocks, appears as a single

uninterrupted karstic area.The Lessini and Beric Hills, the plateaus of Asiago and Tonezza (Vicenza), and

Grappa, Montello and Cansiglio are all karstic areas par excellence, and

important pages in the history of Italian speleology have been written about

them. Although the Belluno area has practically been explored only in recent

years - with completely unexpected results - many Dolomitic mountains are

still totally unknown as regards karstism, and the Dolomites may be

considered a new frontier in Veneto speleology.

The Buso della Rana (in the Vicenza Lessini Hills) is the largest Veneto cave,

more than 25 km long, and it holds the record (which may soon be broken) of

being the longest Italian cave with only one entrance. The Busa di Castel

Sotterra near Montello is one of thelongest caves in the world in

conglomerates (more than 4 km). Two

large Veneto caves nearly reach 1000

m in depth: the Abisso di Malga

Fossetta in the Asiago plateau (-974

m) and the Piani Eterni complex in the

Vette Feltrine (-966 m). The Spluga

della Preta in the Verona Lessini Hills is

third on the list of large Veneto caves.

It remains symbolic for its exploratory

history, a true archetype and source ofhistorical knowledge, not only for the

Veneto but for the whole of Italian

speleology.

Friuli-Venezia Giulia. The Karst,

particularly near Trieste, was the cradle

of Italian speleology and, although

systematically researched for 150Grotta di Castel Sott erra (Montello, Veneto)


21/41

years, continues to supply new revelations. The density of known caves is

extremely high: 3,000 of them over a surface area of only 200 sq.km. And the

mystery of the subterranean course of the river Timavo has not yet been

completely solved. Among the best-known of the Carso caves is certainly

the Abisso di Trebiciano which, by means of a series of shafts, reaches the

course of the Timavo at a depth of more than 350 m.

The Grotta Skilan is the largest in the province, being more than 6 km long

and almost 400 m deep. The best-known cave in this area is certainly the

Grotta Gigante, one of the most popular with tourists. The Grotta GualtieroSavi extends for almost 4 km.

In Friuli, there are some interesting caves in the Julian Prealps, mainly

extending inside alternating carbonatic and flyschoid layers.

For this reason, most of them are horizontal: the Grotta Nuova di Villanova,

partly equipped for tourist visits, is more than 7 km long. Four km is the

length of the San Giovanni dAntro cave, which has at its entrance a small

church and Medieval fortifications

resting on other structures going back

to Roman times.

The Canin massif in the Julian Alps,

composed of Upper Triassic deposits,was the first high-altitude karst to

be systematically explored, and the

Col delle Erbe system (Abisso M.

Gortani and others), 880 m deep and

22 km long, was for many years the

deepest in Italy.

Now the area counts dozens of caves

exceeding -500 m (Foran del Muss

complex, -1100 m, 15 km; Abisso Led

Zeppelin, -960 m, Abisso Modonutti-

Savoia, -805 m, etc.). In the DevonianCalcari di Scogliera(limestone c liffs)

of the Carnian Alps is the Monte

Cavallo di Pontebbe complex, -690m,

which extends into Austrian territory.

In the Cretaceous limestone of the Carnian Prealps, the largest caves are

the Risorgiva di Eolo, more than 5 km long, and the various subterranean

systems of the Pradis area (La Val-Noglar-Mainarda complex, nearly 7

km). New zones of interest have been identified inside the Parco delle

41Dolomiti Friulane (e.g., Landri Scur

di Claut, 4.8 km).

Other interesting phenomena are

those of the Cansiglio plateau,

bordering the Veneto, where the Bus

de la Lum was explored between the

late 19th and early 20th centuries.

However, the most interesting feature

is the Gorgazzo spring, of Vauclusiantype (i.e., its waters entirely fill the

conduit), which collects the copious

waters from the plateau and which,

although starting at 47 m above sea

level, has been explored to a depth of

more than 100 m without the bottom

being reached. It is a very dangerous

cave, and several speleo-divers have

lost their lives in it. It is now explored

by means of small submarine robots.

Liguria. For its climate and geographic position, Liguria has many caves

with archeological and paleontological deposits, some of great significance.

At the frontier with France, the famous Balzi Rossi caves are among the

most important prehistoric sites in Italy. Equally interesting are the Toirano

caves, which may be visited by tourists. One curiosity is certainly the Grotta

del Treno di Bergeggi, which opens off a railway tunnel! In the limestone of

Mt. Tampa, near Giustenice (Savona) is the Grotta degli Scogli Neri (Black

Rock Cave), the longest in Liguria (almost 5 km). Near Finale (Savona) is the

Arma Pollera-Arma do Buio complex, two caves linked by a siphon. The

former cave is also an important prehistoric site.

At the frontier with France is the Grotta della Molesa (Imperia) which, at -253m, is the deepest in this area. Large-scale explorations are currently in

progress in the Balbiseolo cave (Bardineto), a downstream collector of the

Buranco Rampion: speleogists have already discovered almost 5 km of

galleries and are enthusiastic about future prospects.

Emilia Romagna. In the Appennines, a long but discontinuous belt of

Messinian and Triassic evaporitic deposits outcrops. Gypsum, hosting many

very interesting karstic phenomena due to its variety of environments,

40

One of the very many high-altitude shafts inMount Canin (Friuli)

Grotta Nuova at Villanova (Friuli)


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4342 mineralogical aspect and insect fauna, does not contain many concretions

and thus is often not particularly attractive from the c lassical speleological

point of view.

The most interesting system is that of Spipola-Acqua Fredda, not far from

Bologna, more than 10 km long inside an area of such interest that it has

been established as a natural park. It is the longest cave in gypsum in

Western Europe.

The high valley of the Secchia (Reggio Emilia) contains extensive outcrops of

Triassic gypsum, in which karstism develops in underground meanders,i.e., watercourses penetrate evaporatic layers and then return, after an

underground course of greater or lesser distance, to their natural above-

ground beds.

The Fonti di Poiano are some of the most copious karstic springs in the

Appennines. The deepest gypsum cave in the world, the karstic system of

Mt. Caldina, with a difference in altitude of 265 m and a length of 1 km, has

recently been explored.

In the gypsum outcrops of Brisighella are the Abisso Fantini, Grotta della

Tanaccia, and Rio Stella-Rio Basino complex, one of the few fully protected

and conserved Italian caves.

Tuscany. Speleologically, Tuscany means the Apuan Alps: the Mecca of

cave exploration in recent years, but also one of the places where protection

of the subterranean world causes some of the most serious problems.

Many caves are threatened with destruction due to local quarrying for

Carrara marble, some of the highest-quality stone to be found anywhere in

the world.

The Abisso Paolo Roversi, more than 1250 m deep, conceals the Black

Hole, a single shaft more than 300 m deep and so wide that its walls cannot

be seen while speleologists descend it.

The Abisso Olivifer reaches -1215 m, and the Monte Corchia complex -

which, at more than 50 km, is the longest in Italy - goes down to -1190 m.The Saragato-Aria Ghiaccia complex is another of the small number of caves

exceeding -1000 m.

Of historical interest is the Tana che Urla (Screaming Lair), near

Fornovolasco. Although this cave is not particularly long, through it flows a

watercourse which was studied by Vallisneri during his work on

subterranean hydrology in the 18th century. In the same area is the Grotta

del Vento, open to tourists. The hydrothermal Giusti cave, near

Monsummano Terme, contains waters at a temperature of 35C.

Umbria and Marches. The Appennines in this area have extensive outcrops

of Mesozoic limestone. In the Monte Cucco massif is the cave of the same

name, 920 m deep and more than 31 km long.

But the most famous caves here are those of the Gola di Frasassi, not far

from Jesi. The Fiume Vento complex (more than 23 km) is one of the most

beautiful subterranean systems in the world: in part accessible to tourists,

more than 400,000 visitors come to admire it every year.

This is a cave in which recent works aimed at respecting as much as

possible the requirements of theunderground environment and above all

at safeguarding the peculiarities of its

microclimate. In the same area is the

Grotta di Frasassi, at the entrance to

which is a fascinating little temple built

in the early 19th century to a project by

the architect Valadier.

Abruzzo and Molise. Until now, the

carbonatic massifs of the Gran Sasso

and Maiella have only partially revealedtheir enormous potential. One example

is the Cavallone cave (open to tourists),

in which a keen nose can smell the

hydrocarbons present in the rock. Near

the city of LAquila is the Risorgiva di

Stiffe, more than 1.5 km long, open to

tourists. Larger caves are in the Matese,

a carbonatic complex south-west of

Campobasso, where the Pozzo della Neve reaches the respectable depth of

1045 m, and the Abisso Cul di Bove extends for almost 4 km.

Latium. The massif of the Monti Lepini hosts the Grotta del Formale (more

than 4 km) and the Abisso Consolini (about -600 m).

Other karstic areas of great potential are those in the Monti Aurunci, where

the Abisso Vallaroce reaches -565 m; Monti Ausoni, whose waters are

collected by the Pstena caves, more than 3 km (open to tourists); Monti

Simbruini, with the Grotta di Bellegra; and Monti Ernici, with the Abisso degli

Urli (-610 m, more than 3 km).

Some remains of Neanderthal Man were discovered in 1939 in the Grotta

Fiume Vento co mplex (Marche)


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Puglia (Apulia). This is one of the regions where carbonatic rocks outcrop

most extensively. Three separate karstic macro-areas have been identified:

Gargano, Murgia, and Salento. Superficial forms are very widespread on the

Gargano promontory, which also contains one of the largest dolinas in Europe,

the Dolina Pozzatina, more than 600 m across and 100 m deep. The Pulo di

Altamura and Pulo di Molfetta lie on the Murgia plateau. Also of importance

are the Gravine, long karstic valleys which mainly cut the Murgia Tarantina

plateaus.

The best-known cave, the Grotta di Castellana, discovered by Prof. Anelli in1938, is today one of the most popular Italian caves open to tourists. The

deepest cave in the region is the Grava di Campolato (San Giovanni Rotondo),

more than 300 m deep. Many Apulian caves are interesting not only from the

purely speleological viewpoint, but are also of special importance for the

paleo-ethnological evidence they reveal. Examples are the Grotta Paglicci

(Gargano), frequented by man since Paleolithic times, Grotta dei Cervi at Porto

Badisco in Salento, and the Scaloria-Occhiopinto complex at Manfredonia,

used in Neolithic times for water worship. Of great significance is the recentdiscovery of human remains in the Grotta di Lamalunga near Altamura. Lastly,

mention must be made of caves used by man for purposes of worship: from

paleo-Christian until Late Medieval times, caves were lived in by hermits, used

as crypts, and even devoted to the cult of the Archangel Michael.

Unfortunately, much of the deep karstism in Apulia has been profoundly and

severely altered by man in modern times. As well as total destruction of caves

due to quarrying, there are abundant cases in which city sewage has been

sent into natural cavities. Very many caves have been used as dumps for all

4544 Guatteri on the Circeo promontory. Other caves of paleo-ethnological

interest also occur, mainly near Latina.

Campania. The Alburni massif was the first karstic complex to be

systematically explored in Southern Italy. Extensive karstic areas contain the

Grava dei Gentili (-484 m), Grava del Fumo, Grotta del Casone Vecchio, and

others.

At the foot of Monte Alburno is the Grotta di Castelcivita (open to tourists)

recently found to be linked with the active system (Ausino) of water collectionof the overlying massif, forming a complex more than 6 km long.

Grottoes, or sea caves, are of great importance: the best-known in Italy are the

famous Grotta Azzurra on Capri and that of Cape Palinuro. Again at Palinuro is

the Grotta di Punta Galera, more than 1 km long, crossing the narrow

promontory almost completely. Of particular interest is the fact that many of

the grottoes of Cape Palinuro have been, and partly still are, subject to the

circulation of sulphur-bearing fluids which was the main factor influencing the

formation of their cave deposits.

Interesting prehistoric sites are found in many caves between Palinuro and

Camerota. In the Cilento area is the underground course of the river Bussento

which, near Casella in Pittari and Morigerati, enters the carbonatic massif andleaves it again more than 4 km downstream. Until a few years ago, this stretch

of subterranean flow was used to transport sewage!

Grotta di Castellana (Apulia) Grotta di Porto Badisco (Ap ulia): wall paintings

One of several grottoes along Cilento coast (Campania). Note concreted paleosoils at entrance: manycaves were used by prehistoric man


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4746 kinds of materials, sometimes even toxic waste. A significant example is the

Grava di San Leonardo (San Giovanni Rotondo), full of tons of expired

medicines and other hospital material, which could very easily pollute the

underlying water-table.

Basilicata. Near Maratea, in the narrow Tyrrhenian belt of this region, is the

Grotta del Dragone, with about 3 km of galleries, a fossil exit of the karstic

complex of Monte Coccovello.

Although there have been reports of exhalations which might have madeexploration dangerous, due to the presence of a waste dump in a dolina, the

problem now appears to have been solved. Particularly well developed here is

exploration of grottoes, and the Centro Europeo di Speleologia Marina is

located here.

Along the coast is the Grotta delle Meraviglie, partly open to tourists. Nearby,

at Trecchina, is the Grotta di SantAngelo, about 500 m long, full of decorative

concretions and fascinating details.

Also important is the Grotta di Castel Lepre near Marsico Nuovo (almost 2 km),

and even larger is the Grotta I Vucculi at Muro Lucano.

Particular mention must be made of the Matera area, where natural caves

were extensively used as dwellings for humans - in fact, some are stilloccupied!

Calabria. The Abisso del Bifurto in the Pollino massif reaches a depth of -683

m (once the Italian record). Another cave of interest is the Grotta di Serra del

Gufo.

On the Ionian side of Calabria are the Grotte di SantAngelo near Cassano:

described as long ago as 1571, they extend for more than 2 km and are linked

to a system of sulphur springs. Hot sulphur-bearing waters are exploited as

thermal waters in the Antro delle Ninfe near Cerchiara.

The Tyrrhenian side contains many caves of archeological interest. Near

Crotone is the Grotta di Samouri Tour, more than 2 km long, through whichan underground river flows.

Sicily. The carbonatic massifs of the island (Nebrodi, Iblei, Madonie) contain

the Grotta di Pantalica and many other karstic systems, but most

characteristic of all are certainly the lava caves, many of which open on the

flanks of Mount Etna.

The best-known is the Grotta dei Tre Livelli (more than 1300 m long, more than

300 m deep), but the presence - at the foot of a volcano - of a subterranean

glacier in the Grotta del Gelo (frozen cave) is truly out-of-the-ordinary. The

Abisso Profondo Nero has more than 1 km of galleries. The Sicilian

speleological potential is completed by caves in gypsum, like the well-known

Grotta di Santa Ninfa, with more than 1 km of galleries richly covered with

concretions, and SantAngelo Muxaro.

Mention must also be made of the Grotta di Monte Kronio at Sciacca. This is

an important prehistoric site, used in the past as a place of worship and now

practically closed to exploration, due to hot vapours which bring the internal

temperature to more than 38C. This cave can now only be visited with specialequipment.

Sardinia. Extensive outcrops of carbonatic rocks mean that Sardinia is one

of the most interesting areas for

speleologists, with often very long

horizontal caves decorated with

concretions.

In Supramonte di Oliena and around

Dorgali, there are large subterranean

systems like Su Bentu-Sa Oche (15

km) and San Giovanni Su Anzu (11km). But the largest is Codula de Luna,

formed of a join between Su Palu and

Su Spiria, more than 38 km long.

There are also many sea grottoes, very

popular with tourists, such as the

Grotta di Nettuno at Alghero and the

Grotta del Bue Marino at Dorgali.

Short history of speleology and speleological structure in Italy

A brief history of Italian speleology is extremely difficult - above all when werealize that, since the Second World War, Italy has been the country in which

this science developed most.

For thousands of years, caves were lived in and used for protection by man

and animals. Later, they were privileged places for religious or pagan rites, and

have always been treated with respect - perhaps with more fear by Medieval

people than by prehistoric man, who transformed sometimes highly

inaccessible caves into true temples of art (e.g., Grotta dei Cervi, at Porto

Badisco in Apulia).

Grotta di Santa Barbara (Sardinia)


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5150 Bologna, mainly as a tool for

scientific research, which published

a few numbers of the Rivista Italiana

di Speleologia. But the moment

was not yet right for national

coordination of speleology, which

passed through a period of dualism

between exploration and research.

Although the First World War greatlyaffected many associations (for

instance, the Circolo di Udine

emigrated to Florence after the

defeat of Caporetto), it did lead at

last to the conquest by Italy of all

the classic Karst territory, enabling

Friuli-Venezia Giulia to maintain its

position of speleological pre-

eminence on a world scale. But

gradually successful explorations

throughout North Italy followed:from the Abisso Bertarelli (Karst; -

450 m), to the Spluga della Preta

(Veneto), the Abisso Guglielmo in

Lombardy, to the -541 m of the

Antro del Corchia in Tuscany,

reached in 1934.

At that time, limitations were

certainly not dictated by the

capacities of the explorers, but only

by logistic problems and the weight

of all the necessary materials whichhad to be transported into the

bowels of the earth. Explorations

which nowadays can be undertaken

in a few hours by a team of three

speleologists, at that time required

months of preparation, dozens of

men, and several days hard work

by the actual exploring team. These

problems, essentially the same, remained, although with improved materials and

equipment, until the 1970s, when new climbing techniques with advanced kinds

of ropes meant that transport of heavy materials could be greatly reduced while

safety measures were respected. And high-altitude caves could be explored, in

areas already well-known potentially by the fathers of modern speleology.

Returning now to the period between the two world wars, an essential role was

played by the Istituto Italiano di Speleologia, with headquarters in the Grotte di

Postumia, which created a Cave Registry, published the important review Le

Grotte dItalia, and coordinated exploration and research by various expertgroups. This favoured the development of speleology in Italy and its expansion

to the southern regions, but after the Second World War the assets of the

Institute were dispersed, the great speleologists of the past died, and Italy also

lost not only most of the classic Karst, but also its supremacy in the

speleological field.

The dense network of speleological associations started functioning again

around 1950, when the Societ Speleologica Italianawas founded in Verona,

viewed as an association for actively interested speleologists. A few years later,

Gortani re-established the Italian Institute of Speleology in Bologna, this time

focusing principally on scientific research: only after years of strained relations

did the two associations manage to agree.In the 1960s, partly thanks to improved techniques, new explorations were

undertaken, with the record for depth (-878 m) going to the Spluga della Preta

(Veneto). These were the years in which the Apuan Alps, Canin and Marguareis

were explored, still today the subject of constant surveys.

However, in the same years, several deaths occurred which led, among other

things, to the setting-up of the Speleological Rescue Service within the Alpine

Rescue Service.

In those years, speleology was only well-developed in some regions (Friuli-

Venezia Giulia, Piedmont, Emilia-Romagna, Tuscany) and was somewhat

restricted: there was a sort of distance, a coldness, between the two branches

of speleology, exploratory and academic. Fortunately, this state of affairsgradually subsided. Over the next few years, speleological structures and

organizations began to develop and, although each group maintained its

autonomy, regional federations were set up and all administrative bodies

followed the path opened in 1966 by the Friuli-Venezia Giulia Autonomous

Region which was the first to issue legislation for the protection of karstic

phenomena, support speleological activity, and officially constitute a Catasto

Grotte(Cave Registry). Now, almost all Italian regions have their own federations

and functioning cave registries, and more than 300 groups are active.Descent by rope ladder into Viganti shaft (1949)


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53BiospeleologyLEONARDO LATELLA FABIO STOCH

Sphaeromides virei

Biospeleology in Italy

Origins. Initial interest in underground fauna in Italy goes back a long way:

already in the second half of t he 16th century the Vicenza-born Gian Giacomo

Trissino wrote to Fra Leandro Alberti, describing some tiny shrimps found inthe Beric Hills (he was speaking of amphipod crustaceans, now known as

Niphargus costozzae). But he was simply curious, he was not carrying out

scientific research. The first true mention of cave-dwelling animals was made

in 1689, when Baron Johan Weichard Valvasor spoke of a ptit dragon found

in a spring in Carniola. In 1768, Joseph Nicolaus Laurenti described it under

the name of Proteus anguinus, and set it in the group now called caudate

amphibians, although he did not recognize it as a true troglobite. The first

scientific description of an animal really living inside a cave was made by

Ferdinand Schmidt who, in 1831, described Leptodirus hohenwarti, a troglobic

insect found in the Postumia caves. It is perhaps from that date that science

made its official entry into the underground world.A long series of zoological studies began in the 1830s, aiming at knowledge of

cave-dwelling animals. And it was in the Postumia caves, open to visitors for

the first time, that the fulcrum of modern biospeleology may be said to rest.

The first scientific works on subterranean fauna were published in Italy in the

first half of the 20th century. Among these pioneering works were the studies

of Ruffo on cave-dwelling fauna in the Verona region in 1938, and those of

Denis on spring-tails in Italian caves in 1931. But a wealth of literature was

soon created, mainly from taxonomists who were rapidly discovering the

incredible variety of subterranean fauna. After approximately ten years of

inactivity, principally due to the Second World War, work began again with

renewed enthusiasm. The 1950s saw the works of Patrizi and Cerruti on cave-dwelling fauna of Latium and surrounding regions (1950) and Latium and

Sardinia (1953), of Conci on Venezia Tridentina (1951), Ruffo on Apulia (1955)

and Franciscolo on the Savona region (1955), to quote only a few of the most

important works of gen

01 Caves Karstic Phenomena 1

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