D

DINARIC KARST: GEOGRAPHYAND GEOLOGYNadja Zupan Hajna

ZRC SAZU Karst Research Institute

TRAITS OF THE DINARIC KARST

There are many important karst regions around theworld, but the Dinaric karst remains the “classical”karst for many reasons. A large limestone regionwith similar style of landscape, it is the type-site formany features and phenomena. The term karst (kras) isderived from the Kras plateau (the northwest partof the Dinaric karst). From the region originates inter-national terms such as polje, uvala, doline, kamenitza,and ponor. The Dinaric karst is also the landscapewhere karstology and speleology as sciences wereborn. Already three World Heritage properties from theregion, Plitvice Lakes (Croatia), Skocjanske Jame(Slovenia), and Durmitor National Park (Montenegro),are inscribed on the UNESCO list.

The Dinaric karst is geographically and geologicallythe carbonate part of the Dinaric Mountains (Dinarides),which form the western part of the Balkan Peninsulaand the entire Adriatic Sea littoral belt, between42�46�N and 14�21�E. The name of the mountain beltderives from Dinara Mountain, extending in a north-west�southeast direction for a length of 84 km betweenCroatia and Bosnia, with Troglav (1913 m) as the highestpeak. The Dinarides (Dinaric Alps) from a tectonicview include all of the External (Outer) Dinarides andInternal (Central) Dinarides. According to some authorsthe Dinarides also include the Southern Limestone Alpsin Slovenia, but for various reasons they are consideredpart of the Alps.

The boundary line of the Dinaric karst differsdepending on whom you consult (e.g., Roglic, 1965;Gams, 1974) and more or less follows the boundary of

carbonate rocks toward the Pannonian basin (Fig. 1).Present in the region are some noncarbonate rocks, suchas the Eocene flysch rocks in the External Dinarides andclastic sediments and igneous rocks in the InternalDinarides. The western border of the Dinaric karst isrepresented by the Adriatic Sea. The northern border isthe border between the Alps and the Dinarides and fol-lows the Soca, Idrijca, and Sava rivers. The eastern bor-der is not very clear, because there carbonate rocksalternate with noncarbonates of the Internal Dinarides,the Dinaridic ophiolite zone, and the Panonian Basin(Fig. 2). The eastern border is more or less a line fromSamobor and Karlovac in Croatia, Banja Luka in Bosnia,and Pec in Kosovo. According to Roglic (1965), carbon-ate areas between Sarajevo, Uzice, and Durmitor arealso included in the Dinaric karst because, from a geo-logical point of view, these are Adria-derived thrustsheets (e.g., Durmitor, Sandzak plateau). The southernborder is also not very distinctive; it more or less followsthe last carbonates of Prokletije mountain, northwest ofthe river Drim/Drin in Albania.

From the northwest to the southeast, the Dinarickarst is about 650 km long and up to 150 km wide.Covering more than 60,000 km2 this is the paramountkarst region in Europe. The highest peaks are morethan 2000 m high and some of the karst features (e.g.,caves with speleothems) are now below the presentsea level. According to different geological, hydrologi-cal, climate, and geomorphic characteristics, the wholeDinaric karst can be divided into three belts parallelto the Adriatic Sea: low coastal Adriatic karst, highmountain karst, and low continental interior karst.

The Dinaric karst is situated in a humid temperateclimate zone, with prevailing west winds. Along theAdriatic Sea and along river valleys toward DinaricMountains there is a Mediterranean climate withdry and hot summers and wet and fresh winters. Theaverage precipitation there is about 800 mm per year.On the south sides of the Dinaric Mountains a strongdownslope northeast wind burja (bora) is typical. The

195Encyclopedia of Caves. © 2012 Elsevier Inc. All rights reserved.

FIGURE 1 Approximate borders of the Dinaric karst. After Roglic (1965) and Gams (1974).

FIGURE 2 Simplified tectonic map of the Dinaric Mountains. After Schmid et al. (2004) and Sumanovac et al. (2009).

196 D

ENCYCLOPEDIA OF CAVES

inner parts of the Dinaric karst have a mountainousclimate, especially on higher elevations of karst pla-teaus; a moderate continental climate is present in theintermountain basins and in transition areas towardthe Pannonian basin. The Dinaric Mountains act asan orographic barrier where the highest amount ofprecipitation falls (an average of about 3000 mm peryear). The highest annual precipitation is above BokaKotorska bay (about 5000 mm per year).

The vegetation corresponds to the climate and thesoil cover, which on the karst is not very abundant.The Dinaric karst is also well known as limestone des-ert; the bare rocky landscape was and is the result ofclimate conditions, and intense land use over thecenturies. There is almost no vegetation on the islands(Fig. 3) nor along the coast where salt water sprayedby bora impedes all growth. There are large grasslandswith plant species that vary from sub-Mediterraneanto alpine floral elements. Forest is present on higherparts of the plateaus and mountains (e.g., Trnovskigozd, Sneznik, Velebit, Kapela). From the coast towardthe high peaks of the mountains, the typical vegetationis as follows. From the coast toward the mountainsare degradated forests of pubescent oak and horn-beam; they are gradually followed by forests of pubes-cent oak and flowering ash. Vertically, between 700and 1300 m, are coastal beech forests with the indige-nous forests of the black pine. The continental slopesof mountains at elevations between 600 and 900 m arecovered with alpine beech forests. They extend quitelow on the continental side, sometimes descendingto the edges of karst plains. Elevations between1200 and 1400 m are inhabited by beech and fir forests(Abieti-Fagetum dinnaricum) which are also the mostcommon forests of the Dinaric karst. Higher up(above 1600 meters), there is normally a subalpinebeech forest. In different areas are well-preserved

spruce forests, which inhabit altitudes over 1400 m.The highest parts of the mountains are covered withthe indigenous virgin forest of dwarf mountain pine.

The hydrological characteristics of the Dinaric karstare the result of lithology, tectonic structures, climate,and geomorphic evolution. Water in the Dinarickarst is drained toward the Adriatic and Black Sea.There are only a few surface streams in spite of highamounts of precipitation. In the areas with prevailingdolomites, fluviokartic drainage is developed. On karstpoljes are sinking rivers, usually flowing undergroundfrom one polje to another. Underground connectionsbetween different karst poljes of the Dinaric karst areknown, such as the underground water connectionsbetween Gatacko, Nevesinjsko, Fatnicko, Dabarsko,and Popovo poljes (Bosnia and Herzegovina) andOmbla spring at Dubrovnik (at sea level, Croatia).Another example is the river Ljubljanica in Slovenia,draining 1100 km2 (a mean discharge of 56 m3 s21),which crosses four karst poljes. A few large riverscross the carbonate belts along the Dinaric karst:Kolpa, Zrmanja, Krka, Cetina, Neretva, Moraca, Una,Vrbas, Bosna, and Drina are the largest. Most of therivers form deep canyons (e.g., Cetina, Pliva, Tara). Onsome of the rivers tufa deposits are abundant (e.g.,Krka, Zrmanja, Una, and Pliva). Some of the morefamous bodies of water are the Plitvice lakes withdams and waterfalls on the Korana river (Croatia);they were added to UNESCO’s World Heritage List in1979. Huge karst springs are typical of the region, withup to a few hundred m3 s21 maximum discharge (e.g.,Buna (Fig. 4), Bunica, Trebisnjica, and Ljuta). Some ofthe springs along the Adriatic Sea are located underpresent sea level (e.g., Donjobrelska Vrulja belowBiokovo, and Zecica below Velebit); locally they arecalled vrulje.

FIGURE 3 Bare rocky landscape on Pag Island in Croatia. In theforeground is thick-bedded, well-fissured Cretaceous limestone, andin the distance are thin-bedded Paleogene limestones on which stonewalls were made on the boundaries of plots. Photo by the author.

FIGURE 4 Efficacious karst spring of Buna in Bosnia. Photo by theauthor.

197DINARIC KARST: GEOGRAPHY AND GEOLOGY

ENCYCLOPEDIA OF CAVES

STRUCTURAL GEOLOGY OFTHE DINARIDES

The geological evolution of the Dinarides is closelyassociated with the history of the Tethys Ocean, whichclosed during the Mesozoic and Cenozoic as a resultof the convergence of the African and Eurasian plates.Intermediate microplates played an important role inocean shortening. The present geological structuresresulted from post-collision processes in the Alpineorogenic system, which started before 35 Ma (Vrabecand Fodor, 2006). The main period of thrusting andfolding of the area is post-Eocene—the result of post-collision processes between the Africa and Europeplates. The latest tectonic phase in the region startedby counterclockwise rotation of the Adria microplateapproximately 6 Ma BP. The rotation caused reactiva-tion of already existing Dinaric faults, which werethe consequence of the aforementioned thrusting, asdextral strike-slip faults.

Different opinions about the geologic evolutionof the Dinaric system in the northeastern Adriaticregion reflect its complexity. The main tectonostrati-graphic units of the Dinarides (Tari, 2002) are related toEarly and Middle Triassic rifting and Late Jurassic-to-present-day compression.

Early and Middle Triassic rifting was marked bystrong magmatism and horst and graben-related depo-sition overlying the Variscian basement. Along the“eastern” Apulian margin toward the Sava-Vardar,ocean rifting was followed by subduction-generatedextension from the Early Triassic until the LateJurassic. Subduction-related attenuation of the conti-nental crust along the eastern margin of Apuliacaused the formation of a back-arc basin in the oceaniccrust. The remnants of these active continental marginlithologies are found within the eastern thrust beltas the ophiolite melange of the Internal DinaridesOphiolite Belt.

Late Jurassic-to-present-day compression generated(1) the eastern thrust belt, foredeep and foreland;(2) the northern Dinarides accretionary wedge; (3) thewestern thrust belt, foredeep and foreland; (4) theeastern Adria imbricated structures; and (5) wrenchingand tectonic inversion. The Dinaridic carbonate plat-form toward the west presented the foreland of thegenerally west-directed thrusting. During the EarlyCretaceous, compressional stresses began to be trans-mitted westward through the Dinarides, causing themigration of the foredeep basin and regional upliftof the eastern thrust belt. Subduction of the oceanicplate along the northern margin of the Dinaridesresulted in the accumulation of this accretionarywedge from the Maastrichtian to the Eocene. From theend of the Cretaceous until the Early Eocene the entire

carbonate platform was uplifted. During the Eocene,the Dinaridic carbonate platform was finally buriedunder the flysch deposits in the broad foredeep basinof the western thrust belt. At the beginning of theOligocene, collision and progressive subduction ofthe Adria below the Dinarides created the imbricatestructures of the Adria provenance in front of the westernthrust belt. The structural style of the Dinaridic thrustbelt is a result of the polyphase tectonic compressionand the competence of the sedimentary units involved.The competent carbonate rocks are the strongest influ-encing factor on the structural style of the thrust belt.The compression started with ramping along thedeep decollement from the root zone with a south-western tectonic transport. In this way, by progressiveoverstepping of the thrust faults, various structuralforms were created along the eastern and westernthrust belt: fault bend folds, tear fault-related folds,and folded thrust structures reworked by footwalldeformations. The northeast�southwest striking systemof the dextral strike-slip faults during the Oligoceneto Miocene was followed by northwest�southeaststriking and wrenching in the Early and MiddleMiocene, affecting the South Pannonian Basin, thewestern thrust belt, and the Adriatic foreland. Thisactivity is reflected in the large flower structures of theDinaridic thrust belt.

The main structures of the Dinaric karst relief have anorthwest�southeast direction, in the so-called Dinaricdirection. This structural predisposition is visuallyreflected in the direction of high plateaus and karstpoljes from south Slovenia to Montenegro. From a dis-tant view, the Dinaric karst has expressive structuralrelief dependent on overthrust structures and on dextralstrike-slip faults (both in Dinaric direction).

LITHOLOGY OF THE DINARIC KARST

The Dinaric karst denotes an area confined mostly toMesozoic and Cenozoic carbonates of External Dinaridesand Mesozoic carbonates of Internal Dinarides. Car-bonate sedimentary rocks along the Dinarides wereformed on carbonate platform from the Upper Paleo-zoic to the Paleocene. The youngest limestones arepresent in the belt along the Adriatic coast, fromEocene, Paleocene, to Cretaceous in age; more or lessCretaceous and Jurassic limestone and dolomitesare present in the middle (External Dinarides) andnortheastern part (Internal Dinarides); Triassic lime-stones and dolomites are mainly parts of the middle(External Dinarides) and northeastern outer parts(Internal Dinarides) of the Dinaric karst. Geologicaldata (e.g., Vlahovic et al., 2002) indicate that theExternal Dinarides were formed by the destruction of

198 D

ENCYCLOPEDIA OF CAVES

a single, yet in morphological terms highly variable,shallow water carbonate platform: the Adriatic CarbonatePlatform. There is confusion in the scientific literature dueto the different names used for the same shallow-watercarbonate platform and ideas of two existing carbonateplatforms at the same time. The platform was verydynamic in some periods because of its paleogeographicposition during the Mesozoic, especially during the LateCretaceous. The final disintegration of the platform areaculminated in the formation of flysch trough(s) in the LateCretaceous and Paleogene and the subsequent uplift ofthe Dinarides.

Along the Dinaric karst, karst features are favoredespecially in massive and thick bedded Cretaceouslimestones and Jelar Breccia of the Oligocene or youn-ger age. Upper Cretaceous massive limestones areexceptionally well karstified because of their properties(very pure). In Jelar Breccia solutional karst featuressuch as karren, dolines, conical hills, and caves arealso well developed. Along the south and southwestparts of Velebit, where breccia is located, ridges of con-ical hills (kuk in the local language) are numerous.Between these hills, big and deep karst depressions(duliba in the local language) are developed. Amongthe most well known are Hajducki and Rozanski kukovinear Zavizan (Northern Velebit National Park); Dabarskikukovi near Baske Ostarije; Bojinac (Fig. 5) abovePaklenica Canyon (National Park Paklenica); and Tulovegrede on the south edge of the Velebit. The thick-beddedJelar Breccia, comprised predominantly of angular,poorly sorted clasts of Cretaceous limestones and dolo-mites, Triassic carbonates, and Paleogene limestones,covers large areas along the northeastern Adriatic coaston the southwest rim of Velebit Mountain (westernCroatia). The largest outcrop is .100 km long, 2�10 kmwide, and thicker than 500 m in places. The Jelar Breccia

is usually considered a result of the disintegration offrontal parts of the major thrusts. The large leveled sur-faces and caves are developed also in Eocene�OligocenePromina Beds (Promina Formation) which consist ofnoncarbonate and carbonate parts. Carbonate conglom-erates may be seen, for instance, on mountain Promina,at Sjevernodalmatinska zaravan (northern DalmatianPlain; the area between Velebit, Novigradsko more andriver Krka).

During the Pleistocene, Dinaric Mountains with eleva-tion above 1100 m were glaciated. Stagnant glaciers werecovering the top of the plateaus with small tonguesflowing over plateau edges. Valley glaciers reshaped theoriginal fluvial valleys into typical U-shaped valleys anddeposited vast amounts of sediments. There is a numberof characteristic glacial features such as hanging valleys,remains of moraines, fluvioglacial sediments, erraticblocks, and striated cobbles and boulders. The remainsof Pleistocene glaciations are visible on mountains andplateaus from Slovenia to Montenegro; for example,Sneznik, Risnjak, Velebit, Orjen, Lovcen, and Durmitor.

KARST FEATURES OF THEDINARIC KARST

The most characteristic relief forms of the Dinarickarst are high karst plateaus, numerous poljes in thecentral part stretched in northwest�southeast direc-tion, enormous leveled surfaces, various dolines, largeand deep caves, sinking rivers, and abundant springs.Karst forms are surface and subsurface karst featuresformed mainly by solutional processes of carbonaterocks of the region which are extremely well foldedand fractured due to tectonic events. Linear faulting israre in carbonate rocks; usually carbonates are frac-tured to different degrees. According to the degreeof deformities of the bedrock, we distinguish in carbo-nates fissured (fissures), broken (blocks of rock), andcrushed zone (clay, silt, breccia). The presence offractured zones is very important for karstification andformation of karst features usually favor defined ones;for example, fissure zones are important for formationand location of karren fields, giant grikelands, andstrings of dolines.

On various limestones, dolomites, and so on, severalkinds of karren are developed, especially on massiveand thick-bedded limestone. Due to its specific mech-anical and petrographic properties, the Jelar Breccia ischaracterized by an abundance of dissolution featureson exposed surfaces (e.g., solutional runnels, heel-prints, corrosional steps, kamenitzas).

The most typical karst features of the Dinarickarst are depressions of various sizes: dolines, col-lapse dolines, uvalas, and poljes. Dolines are closed

FIGURE 5 Karst features in Jelar Breccia on Bojinac, SouthVelebit in Croatia. Photo by the author.

199DINARIC KARST: GEOGRAPHY AND GEOLOGY

ENCYCLOPEDIA OF CAVES

karst depressions of different sizes and genesis(Ford and Williams, 2007). Solution dolines formwhere vertical karst drainage is present and sup-ported with suitable lithology, geological structures,slope inclination, and long enough time. In someareas their distribution is very dense, up to 200dolines per km2. Where dolines totally pock someparts of the surface and occupy almost all the space,we are dealing with typical polygonal karst (egg-box-like topography). Landscapes displaying polygonalkarst can be found in many places in the Dinarickarst; for example, on Biokovo above Makarska, onplateaus above Boka Kotorska bay, and on high pla-teaus in Herzegovina. Where the principal process ofthe formation of a doline is the collapse above under-lying caves, it is called a collapse doline. Collapsedolines are common features of the Dinaric karst andare especially numerous above known large caves.More than 15 large collapse dolines are located abovethe underground stream of river Reka which sinks toSkocjanske Jame in southwest Slovenia. The biggestcollapse dolines are near Imotski (Croatia). With adepth of 528 m, Crveno Jezero is the deepest ofthem; its bottom water is about 280 m deep. On theDinaric karst many dolines are inherited forms ofprimary caves and shafts (Mihevc, 2007), which, due tosurface denudation, become part of the karst relief.Many large and deep closed depressions are locatedalong the high Dinaric plateaus (e.g., Sneznik, Velebit).They are named konta, draga, or duliba and their originas solutional or collapse dolines is not always clear.During the Pleistocene they were significantly remo-deled by glaciation and frost action and in some ofthem moraines are found.

Uvalas are polygenetic-formed karst closed depres-sions, which are connected to the geological structure(Calic, 2009), usually in broken (well-fractured) zonesof regional extension. They are larger than dolines(km-scaled), they are mainly disconnected with thekarst water table, and they can look like a small poljewithout a surface stream. Uvalas are frequent relieffeatures of the Dinaric karst but they are not devel-oped at low elevations and on leveled surfaces.

Karst poljes are large karst depressions with flat bot-toms, which are the result of solutional processes andkarst water drainage. Due to different geological andhydrological factors Gams (1978) distinguished fivetypes of karst poljes: border polje, piedmont polje in alluvialvalley, peripheral polje, overflow polje, and baselevel polje.Most of large karst poljes of the Dinaric karst are basele-vel poljes in their origin even if they have some noncar-bonate rocks at their bottom. Water on the surfacecauses base-leveled corrosion, lateral corrosion (mar-ginal corrosion), and consecutive leveling of the rockybottom at the water table. Oscillation of the water

table causes hydrological phenomena such as springs,ponors, estavelas, floods, and intermittent lakes.

The karst poljes of the Dinaric karst are structur-ally controlled and almost all of them are stretchedalong overthrust edges and fault zones of regionalimportance in so-called Dinaric direction (north-west�southeast). Between parallel dextral strike-slipfaults or between normal faults, separate blocks aresunk to different elevations (e.g., pull-apart basinformation; graben formation). Some of them are juston the water table level, or they were in the past.These blocks of carbonates at the water table are, orwere, leveled and sometimes also laterally enlargedby corrosion and karst poljes were formed. Someparts of the poljes sank, or they are still sinking, andthese immersed parts are usually filled up withsediments. Many of the karst poljes along the Dinarickarst contain fluvial, lacustrine, or glacial Neogeneand Quaternary sediments up to few hundred metersdeep (e.g., Nevesinjsko, Gacko, Glamocko, and Livanjskopoljes). The proofs for existing lakes in sinking basinsduring the Miocene and Plio-Pleistocene are also fossilfauna and coal-bearing deposits in some of the karstpoljes (e.g., Kocevsko, Sinjsko, Duvanjsko, Livansko, andGacko poljes) from Slovenia to Montenegro. Older sedi-ments are in karst poljes in the northeast and centralarea of the Dinaric karst, while in the bottoms of thepoljes on the southwest side of the highest karst plateaus(e.g., the southwest part of Slovenia, Istria, and Velebit,and along the Adriatic Sea) sediments are in thinnerlayers or they do not exist (e.g., Planinsko polje inSlovenia). It is also seen that in some of the Dinaric faultzones in the area, karst poljes are not developed yet(blocks are not developed or sink to the water table; e.g.,along the Rasa fault in southwest Slovenia). The age ofthe sediments in the karst poljes (whether Miocene,Pliocene, Pleistocene, or Holocene) decline in age fromeast to west and the presence of the developed karstpoljes along fault zones is in connection with the youn-gest dextral strike-slip tectonic influence by recent Adriamicroplate movements. Below the sediments, moreor less leveled rocky bottoms of karst poljes exist. At dif-ferent elevations of karst polje bottoms or at their edges(e.g., polje of Lika, Nevesinjsko polje, and Fatnicko polje)or even between poljes (e.g., between Fatnicko andDabarsko poljes) are leveled surfaces, which are rem-nants of a time when polje bottoms were corroded at thewater table as one single unit and now they are as sepa-rate blocks left behind (they are no longer sinking). Onsome of these older leveled blocks (surfaces) dolinesare already formed (e.g., the north central part ofNevesinjsko polje and the south edge and southeast partof Fatnicko polje).

Leveled surfaces are often connected with baselevelcorrosion on karst poljes, but they can be also produced

200 D

ENCYCLOPEDIA OF CAVES

after a long period of denudation on the input margin(Ford and Williams, 2007). The complex of processesproducing corrosional plains in karst has been calledlateral solution planation or corrosional planation andinvolves a combination of vertical dissolution, lateralundercutting of hillsides, and spring head sapping.Larger leveled plains are found along the Dinaric karstin south Slovenia, in Istria, between Karlovac (Croatia)and Bihac (Bosnia), Dalmatia (Fig. 6), and in Bosnia andHerzegovina. Corrosional plains cut different geologicalstructures (e.g., folds, lithology) in the larger area. Inlocal languages, leveled surfaces are named ravnik,podolje, and zaravan. In some of them rivers formed can-yons, for example, at Krka in the Sjevernodalmatinskazaravan (north Dalmatian karstic plain) or at riverCetina in the Zadvarska zaravan; some of old ones arealready dissected by dolines and/or conical hills (e.g.,Kras plateau in Slovenia).

Contact karst develops on the contact between per-meable (karst) and nonpermeable (nonkarst) rocks,for example, on the contact between carbonates andPaleozoic and Mesozoic clastic rocks or Eocene flyschrocks on the outer borders of the Dinaric karst orwithin its borders. Contact karst is a landform associ-ated with allogeneic input. Different karst features arelimited with the border belt of carbonate areas andthey are influenced by sinking rivers. There are manybig sinking rivers along Dinaric karst (e.g., Reka sinksin Skocjanske Jama, river Pivka sinks in PostojnskaJama, and Zalomka River sinks to the Biogradskiponori). Remnants of old river streams are dry valleys,which lack an active watercourse over all or partsof their length for at least part of the year, becausewater is lost in karst or is in a much lower position.For instance, there are two dry valleys crossing theKras plateau in southwest Slovenia: the largest one inSlovenia is the 400-m-deep Cepovanski dol betweenTrnovski gozd and Banjscice plateaus, and another bigdry valley is situated in upper part of river Bregavabetween Dabarsko polje and Stolac in Herzegovina.A contact karst feature is also the blind valley, which isa valley cut by a stream flowing from insoluble rocksonto soluble rocks and sinking in a ponor. A series ofblind valleys is developed in Matarsko podolje in

southwest Slovenia, where along geological contactbetween flysch and limestones 17 brooks sink into thekarst edge. Blind valley bottoms are widened by basele-vel and lateral corrosion (Mihevc, 2007).

More than 20,000 caves are known in the Dinarickarst; they are located from the high mountains tobelow present sea level in the form of vertical shafts orhorizontal passages. Some of the caves are active andsome of them are relict parts of karst drainage systems.Caves are developed in various carbonate rocks ofthe region and their formation was influenced by thelocal presence of different geological structures andposition of water gradient (base level). The deepestexplored caves are known from the North Velebit inCroatia; for example, shafts Lukina Jama-Trojama(21392 m), Slovacka Jama (21320 m), Velebita cavesystem (21026 m) with a 513-m underground verticalshaft, and Meduza (2679 m). Several significant caveswere discovered in the Jelar Breccia and Liassic lime-stone of the Crnopac area (South Velebit). Their mainmorphological characteristic is a network of multi-phase cave passages, some of them with very largecross-sectional dimensions. The most important cavesof Crnopac massif are Munizaba (5993 m long,2437 m) and Kita Gacesina (10,603 m long, 2456 m).There are many horizontal caves linked to the ponorssuch as Postojnska Jama (a 20,570-m-long system of 5caves) and Skocjanske Jama (6200 m long) in Slovenia,and Ðulin ponor-Medvedica (16,396 m long) inCroatia. Some of the horizontal caves are managed forcave tourism; notably Postojnska Jama, Cerovackepecine (3800 m long) in Croatia, Vjetrenica (6700 mlong) on Popovo polje in Bosnia and Herzegovina, andLipska pecina (3500 m) in Montenegro.

Twenty years ago the prevailing thinking was thatthe surface of the Dinaric karst was formed in theMiddle Pliocene (Habic, 1991). Before then karst wascovered and contained by impermeable rocks, andwaters flowed superficially over impounded carbonaterocks. Later tectonic movements contributed to surfacetransformation and to karst dissection and surfacestreams disappeared into karstic underground. Theevidence of the surface water flows were clastic(fluvial) sediments found on the karst surface. With

FIGURE 6 Sjevernodalmatinska zaravan (north Dalmatian karstic plain in Croatia) cuts different geological elements; in the distance isPromina Mountain. Photo by the author.

201DINARIC KARST: GEOGRAPHY AND GEOLOGY

ENCYCLOPEDIA OF CAVES

different methods the denudation rate in humid tem-perate zone was calculated to about 20�50 m per mil-lion years (Gams, 1974). With this rate of surfacedenudation many caves were already breached andtheir ceilings were removed—this is how roofless caveswere formed (Mihevc, 2007; Fig. 7)—and from somecaves only their insoluble clastic sediments remain onthe karst surface. Unroofed caves are calculated to beolder than 5 Ma BP. The paleomagnetic and magnetos-tratigraphic research of karst sediments in Slovenia(Zupan Hajna et al., 2008) has been carried out since1997. More than 2500 samples were taken and analyzedin 36 different profiles at 21 locations in caves and onthe surface. The results were in some sites calibrated bythe thorium-uranium (Th-U) method and by paleonto-logical and geomorphological analyses. Calibrated datacontributed to reconstruction of speleogenesis, deposi-tion in caves, and indirectly to evolution of karst sur-faces and succession of tectonic movements. Theevolution of caves in Slovenia took part within onepost-Eocene karstification period. The period containsdistinct phases of massive deposition in now-existingcaves with still preserved sediments dated to about5.4�4.1 Ma BP (Miocene�Pliocene), 3.6�1.8 Ma BP(Pliocene�Quaternary), and Quaternary. From the ageof the cave sediments it follows that the caves have tobe even older.

LAND USE

The Dinaric karst has a long history of humanimpact such as deforestation and transformation intostony semidesert, and also a long history of reforesta-tion (Gams and Gabrovec, 1999). Originally the karstwas completely forested. When the human economychanged to stockbreeding and farming, the process ofanthropogenic deforestation began. In the history there

have been two main reasons for deforestation (Kranjc,2008): (1) economic (the requirements of new land,pastures, timber use, and trade) and (2) social (localincreases in population, mass migration, wars, andraids). Nowadays dense natural forests, extensive forestplantations, dry karst shrublands, and also completelybarren karst areas can all be found on the Dinaric karst.

The main regions of the Dinaric karst, the Krasplateau, the islands, and the low plateaus of theDalmatian coast, present the types of land use typical ofMediterranean countries which produce changes in thesurface (Nicod, 2003): the deforestation and adaptationof the karst surface for agriculture; the stone clearingeffects; the use of extracted stones for dry-stone wallsand hillslope terraces; and the land reclamation andmanagement in the dolines, uvalas, and poljes. Drystone wall terraces were built around hillsides in orderto limit soil erosion and to provide small fields foragriculture. Stones removed from the soil have mostlybeen accumulated in dry walls. In some areas the onlyagriculture surfaces were cultivated dolines. With thedeclining role of agriculture, increased social mobility,and an aging and insufficient agricultural workforce,terraces and small gardens in the dolines have lost theirformer role and now they have been almost entirelyreplaced by meadows and bushes.

The environmental problems, on which many fac-tors interfere, were of interest to various and multidis-ciplinary researchers. During the Austro-HungarianEmpire and Yugoslavia kingdom, surface streamswere regulated, ponors were widened, and screenswere installed in front of them to hold back deposits,all to shorten the flood time in the karst poljes. AfterWorld War II the construction of dams on rivers andstreams for water reservoirs started. The managementsin the large Dinaric poljes pose very intricate and diffi-cult problems (e.g., water tightness of artificial lakesand draining of natural habitats) depending on thestructural and hydrogeological conditions. They havebeen studied in many works (e.g., Bonacci, 1987;Milanovic, 1981).

See Also the Following Article

Diversity Patterns in the Dinaric Karst

Bibliography

Bonacci, O. (1987). Karst hydrology: With special reference to the Dinarickarst. Berlin: Springer-Verlag.

Calic, J. (2009). Uvala: Contribution to the study of karst depressions, withselected examples from Dinarides and Carpatho-Balkanides (Doctorthesis). Nova Gorica, Slovenia: University of Nova Gorica.

Gams, I. (1974). Kras. Ljubljana, Slovenia: Slovenska matica.Gams, I. (1978). The polje: The problem of definition. Zeitschrift fur

Geomorphologie, 22(2), 170�181.

FIGURE 7 Unroofed cave near Grotta Gigante at the Italian partof Kras plateau. Photo by the author.

202 D

ENCYCLOPEDIA OF CAVES

Gams, I., & Gabrovec, M. (1999). Land use and human impact in theDinaric karst. International Journal of Speleology, 28B(1�4), 55�77.

Habic, P. (1991). Geomorphological classification of NW Dinarickarst. Acta Carsologica, 20, 133�164.

Kranjc, A. (2008). History of deforestation and reforestation in theDinaric karst. Geographical Research, 47(1), 15�23.

Mihevc, A. (2007). The age of karst relief in West Slovenia. ActaCarsologica, 36(1), 35�44.

Milanovic, P. T. (1981). Karst hydrology. Littleton, CO: Water ResourcesPublications.

Nicod, J. (2003). Understanding environmental problems in Dinarickarst. Dela, 20, 27�41.

Roglic, J. (1965). The delimitations and morphological types of theDinaric karst. Nase jame, 7(1�2), 79�87.

Schmid, S. M., Fugenschuh, B., Kissling, E., & Schuster, R. (2004).Tectonic map and overall architecture of the Alpine orogen.Eclogae geologicae Helvetiae, 97, 93�117.

Sumanovac, F., Oreskovic, J., Grad, M., & ALP 2002 Working Group(2009). Crustal structure at the contact of the Dinarides andPannonian basin based on 2-D seismic and gravity interpretationof the Alp07 profile in the ALP 2002 experiment. GeophysicalJournal International, 179, 615�633.

Tari, V. (2002). Evolution of the northern and western Dinarides:A tectonostratigraphic approach. EGU Stephan Mueller SpecialPublication Series, 1, 223�236.

Vlahovic, I., Tisljar, J., Velic, I., & Maticec, D. (2002). The karstDinarides are composed of relics of a single Mesozoic platform:Facts and consequences. Geologia Croatica, 55(2), 171�183.

Vrabec, M., & Fodor, L. (2006). Late Cenozoic tectonics of Slovenia:Structural styles at the northeastern corner of the Adriatic micro-plate. In N. Pinter, G. Grenerczy, J. Weber, S. Stein & D. Medak(Eds.), The Adria microplate: GPS geodesy, tectonics and hazards(NATO Science Series, IV, Earth and Environmental Sciences, 61)(pp. 151�168). Dordrecht, Germany: Springer.

Zupan Hajna, N., Mihevc, A., Pruner, P., & Bosak, P. (2008).Paleomagnetism and magnetostratigraphy of karst sediments in Slovenia.(Carsologica, 8, Zalozba ZRC) (p. 266). Ljubljana, Slovenija. Slovenia:Zalozba ZRC, Postojna.

DIVERSITY PATTERNSIN AUSTRALIAWilliam F. Humphreys

Western Australian Museum, University of Adelaide andUniversity of Western Australia

INTRODUCTION

The diversity of subterranean fauna in Australia,and tropical areas worldwide, has not long been recog-nized. Until recent decades, Australia was thought tobe deficient in overtly cave-adapted (troglomorphic)animals. This circumstance was considered to haveresulted from a number of causes: (1) the relativesparseness of carbonate rocks in Australia, as found inother Gondwanan fragments, compared with theworld average (Fig. 1); (2) the general aridity of the

continent—it is the most arid inhabited continent, two-thirds of which receives less than 500 mm of rainannually—generally resulting in both dry caves andlow input of food energy into the underground voids;(3) the global lack of cave-adapted animals in tropicalareas; and (4) the lack of widespread and repeated gla-ciations, which was perceived to be the main factordriving the evolution of troglobites in the NorthernHemisphere, then the focus of research on subterra-nean animals. Concomitantly, in Australia there wasperceived to be a high proportion of animals foundonly in caves but not specialized for cave life, that is,lacking overt troglomorphisms. Although not articu-lated, these arguments would have applied also to sty-gofauna, the inhabitants of underground waters inboth karstic and alluvial aquifers.

Understanding the biogeography of an area is relianton having a broad spatial and taxonomic sample of thebiota, a comprehensive taxonomy, a well-developedsystematic and paleoclimate framework, and a fullydeveloped geographical understanding (especially ofpaleodrainage and plate tectonics). There are seriousdeficiencies in information on most of these fields ofendeavor in Australia. The taxonomic and systematicframework is very patchy and many groups of interestto hypogean questions remain largely unstudied(e.g., Thysanura, Collembola, Diplura, Oligochaeta), orare just beginning to be studied, so it is still too earlyfor them to contribute in detail to biogeographicalunderstanding (e.g., many higher taxa in Oligochaeta,

FIGURE 1 Karst areas of Australia and the bioclimatic zones:II, tropical; III, subtropical dry; IV, transitional zone with winter rain;V, warm temperate; II�IV warm temperate/tropical transition zone.The two pink areas within the common outline represent the Pilbara(north) and Yilgarn (south) cratons and their associated orogens thattogether comprise the western shield. After Hamilton-Smith andEberhard, 2000. Graphic by K. G. Grimes, modified.

203DIVERSITY PATTERNS IN AUSTRALIA

Encyclopedia of Caves. © 2012 Elsevier Inc. All rights reserved.