Osovniška jama, the Cave in Isolated Karst in the East of Slovenia

Osovniška jama je bila odkrita leta 2001 med izkoriščanjem srednjemiocenskega apnenca v kamnolomu Pijevci v vzhodnem delu Slovenije. Subpanonski osameli kras je značilen za ta del Slovenije. Ta kras je razvit na majhnih otokih plitvega apnenca. Subpanonski osameli kras je poseben tip krasa na litotamnijski apnencih, kjer so površinske oblike dobro razvite ni pa znanih daljših jam. Osovniška jama je dolga okrog 290 m in je sedaj najdaljša jama v temu delu Slovenije. Na tem področju vpadajo apnenčeve plasti generalno proti JV pod kotom 20°. Glavne tektonske strukture so v smereh SZ-JV in V-Z. V kamnolomu je grebenski apnenec masiven in razpokan v smereh V-Z, SZ-JV in S-J. Jama generalno sledi smeri SZ-JV. Oblika rovov še zmeraj kaže na oblikovanje v freatičnih pogojih; večinoma pa je izraženo preoblikovanje in oblikovanje rovov v vadozni coni. V nekem obdobju razvoja jame so alohtoni klastični sedimenti napolnjevali zgornje dele jame, kasneje pa so bili skoraj popolnoma izprani. V jami je veliko kapniških tvorb.Osovniška jama has been discovered in 2001 during the exploitation of the Middle Miocene limestone in Pijevci quarry in the E part of Slovenia. Isolated subpanonian karst is typical of this part of Slovenia. This karst developed on small isolated patches of shallow limestone. Subpanonian isolated karst is a special type of karst on Lithothamnian limestone, where the surface karst forms are very well developed but no long caves were known. Osovni¹ka jama is about 290 m long and now is the longest cave in this part of Slovenia. In this area the general dip of limestone beds is towards SE at dip angle 20°. The main tectonic structures of the area are in NW-SE and E-W directions. In the quarry, reef limestone is massive and fissured in E-W, NW-SE and N-S directions. The cave generally follows the NW-SE direction. The shape of channels still shows its formation in phreatic conditions; but mostly the transformation and formation of its channels in the vadose zone is expressed. At some time in this cave development allochtonous clastic sediments filled up the upper parts of the cave; afterwards they were almost entirely washed away. There are a lot of flowstone formations in this cave

Origin of Fine-Grained Carbonate Clasts in Cave Sediments

V vzorcih jamskih klastičnih sedimentov se velikokrat nahajajo velike količine drobnih karbonatnih zrn. Ugotovila sem, da je njihov izvor v mehkih belih conah preperele karbonatne kamnine s sten jamskih rovov. Preperele cone apnenca in dolomita nastajajo na jamskih stenah, kadar nanje deluje selektivna korozija. Nepopolno raztapljanje pripravi karbonatno kamnino na mehansko erozijo in transport njenih trdnih delcev. Kjer je preperela karbonatna kamnina v stiku z vodo, tekočo ali kapljajočo, ta lahko trga njene, s selektivnim raztapljanjem izpostavljene delce. Voda jih odnaša naprej po rovih, ko transportna moč vode pade, se delci usedajo v obliki drobnozrnatega karbonatnega sedimenta velikostnega reda gline, melja in drobnega peska.In many samples of cave clastic sediments the high amount of carbonate clasts is significant. It was found out that their origin is usually in soft white zones of weathered carbonate rock on cave walls. Weathered zones of limestone or dolomite form on the cave walls when the selective corrosive is going on. Incomplete dissolution prepares the carbonate rock for the mechanical erosion and transport of its particles. Where the weathered carbonate rock is in contact with water, both flowing and dripping, it may tear off the particles resulting from selective corrosion. Water carries them along cave passages and when its transporting power decreases, particles accumulate in the form of a fine-grained autochthonous carbonate deposit, in size of clay, silt or fine sand

The Caves of the Contact Karst of Beka and Ocizla, the SW Slovenia

Beško-Ocizeljski jamski sistem je razvit v območju kontakta med paleocenskim apnencem in eocenskim flišem na nadmorski višini 350 m na jugozahodu Slovenije. Plasti apnenca generalno vpadajo proti NW, najizrazitejše prelomne strukture so v dinarski in prečnodinarski smeri. S fliša na kontakt z apnencem pritekajo trije večji in en manjši potok, ki ponikajo v apnenec. V jamski sistem se povezujejo Ocizeljska jama, Blažev spodmol, Maletova jama s slapom, Jama z naravnim mostom, Jurjeva jama v Lokah in Jama S-4/Socerb od katerih vhodi v štiri jame delujejo kot občasen ponor. Skrajna vhoda sta drug od drugega oddaljena 500 m. Voda se v sistemu istočasno pretaka na različnih nivojih in drenira proti Boljuncu. Za razvoj jamskega sistema, generalne smeri jamskih rovov in pretakanje vode v sistemu, je najpomembnejši sistem vzporednih tektonskih ploskev z vpadom 220/50-80. The cave system of Beka-Ocizla is developed in the area of contact between Palaeocene limestone and Eocene flysch at 350 m a.s.l. in south-western Slovenia. The beds of limestone could generally be traced in the direction towards NW; the most distinct tectonic structures are in the Dinaric direction and transversely to the Dinaric direction. Three bigger streams and one smaller flow from the flysch on the contact with limestone, which sink into the limestone. The following caves are connected to the cave system: Ocizeljska jama, Blažev spodmol, Maletova jama s slapom, Jama z naravnim mostom, Jurjeva jama v Lokah and Jama S-4 / Socerb; the entrances of four of those caves function as occasional ponors. The least close entrances are 500 m away from each other. The water in the system simultaneously flows on various levels and drains in the direction of Boljunec. The system of parallel fault planes with dip 220/50-80 is the most important for the development of the cave system, the general direction of the caveʼs passages and the flow of water in the system

Palygorskite in caves and karsts: a review

Palygorskite is fibrous mineral representing the transitional phase between chain silicates and layer silicates with modulated phyllosilicate structure. Although often found in carbonate environments, it forms quite uncommon constituent of cave fills. Palygorskite occurs in cave fills in two forms: (1) allogenic palygorskite which in arid and semiarid conditions can represents substantial constituent of cave fills, often associated with smectite, gypsum, calcite and halite; it is airborne or transported by surface run-off to caves from desert soils and paleosoils, calcretes, dolocretes and related deposits in cave surroundings. (2) Authigenic palygorskite occurs as in situ precipitate in cave fills from percolating water solutions and/or transformation of smectite and kaolinite in dry evaporative conditions and suitable geochemical composition of solutions. In carbonate host-rocks palygorskite fills fissures and faults and often it is found in cave walls. It occurs commonly as part of the “mountain leather” as a result of hydrothermal and/or weathering processes or represents a product of in situ chemical precipitation from percolating meteoric solutions with suitable pH a redox conditions and chemical composition.Key words: palygorskite, caves, karst.Paligorskit v jamah in krasu: pregledPaligorskit je vlaknat mineral, ki je prehodna fazo med inosilikati in listastimi silikati z modulirano strukturo filosilikata. Čeprav je pogost v karbonatnih okoljih, je precej neobičajna sestavina jamskih sedimentov. Paligorskit se v jamah pojavlja v dveh oblikah: (1) kot alogeni paligorskit, ki je v sušnih in polsuhih razmerah lahko znaten sestavni del jamskih sedimentov, pogosto povezanih z montmorillonitom, sadro, kalcitom in halitom; v teh primerih gre za eolski nanos ali pa za transport v jame s površinskim transportom iz puščavskih tal in paleotal, kalkret, dolokret in podobnih sedimentov; (2) kot avtogeni paligorskit se pojavlja v jamah kot »in situ« oborina iz prenikajočih raztopin in/ali z obarjanjem med transformacijo montmorillonita in kaolinita v jamskih sedimentih v suhih razmerah izhlapevanja in primerno geokemično sestavo raztopin. V karbonatnih kamninah paligorskit zapolnjujejo razpoke in prelome in ga pogosto najdemo na jamskih stenah. Običajno se pojavlja kot del “gorskega usnja”, ki je posledica hidrotermalnih in/ali procesov preperevanja. Lahko pa nastane tudi zaradi in situ kemičnega obarjanja iz prenikajočih meteornih raztopin z ustreznim pH, redoks potencialom in kemično sestavo.Ključne besede: paligorskit, jame, kras

Nepopolno raztapljanje karbonatnih kamnin v kraških jamah Slovenije

Research represent in this monograph (Incomplete Solution Of Carbonate Rocks In Karst Caves Of Slovenia) was dedicated to incomplete solution of limestones and dolomites in karst caves~that is to occurrence of thick, soft weathered zones of “soluble” residue of carbonate rocks. With field and laboratory analyses I have tried to find out what is happening within the carbonate rocks during weathering and why they do not dissolve completely. Solution penetrates into the rock along various textures and structures. Results of analysis have shown that during weathering limestones and dolomites become purer~Mg, Sr and U are leached out, structure of the rock becomes more porous. In the cases when surface of weathered rock come in contact with flowing water, the water tears exposed particles and transports them away. If water does not flow over the exposed particles fast enough, they remain attached to the wall of the cave. The ratio between corrosion and the mechanical erosion of carbonate rocks on cave passages walls is more significant for the formation of roughness and rocky relief on the wall than for the growth of the passage. Microorganisms are present in the processes, but it is not yet known if they contribute to the weathering. From research follows that zones of white porous rock on cave walls are a product of weathering and are not precipitated secondary minerals.Raziskave, predstavljene v monografiji, so bile posvečene nepopolnemu raztapljanju apnencev in dolomitov v kraških jamah~to je pojavljanju debelih, mehkih con »topnega« ostanka karbonatnih kamnin. S terenskimi in laboratorijskimi analizami sem skušala spoznati, kaj se dogaja v karbonatnih kamninah med preperevanjem in zakaj se popolnoma ne raztopijo. Raztapljanje prodira v kamnino po različnih strukturah in teksturah. Rezultati analiz so pokazali, da se tako apnenec kot dolomit med preperevanjem čistita~izlužijo se Mg, Sr in U, struktura kamnine pa obenem postaja vedno bolj porozna. V primerih, ko je površina preperele kamnine v stiku s tekočo vodo, voda z njene površine trga izpostavljene delčke in jih odnaša. Če voda ne teče dovolj hitro čez izpostavljene delčke, ostanejo na steni rova. Razmerje med korozijo in mehansko erozijo karbonatne kamnine v steni jamskega rova je bolj pomembno za oblikovanje hrapavosti in različnih skalnih oblik na stenah kot pa za samo rast rova. Mikroorganizmi so prisotni, ne vemo pa še ali sodelujejo pri preperevanju. Iz raziskav sledi, da so cone bele porozne kamnine na jamskih stenah produkt preperevanja in ne izločanja sekundarnih mineralov

Karst landforms Within Noctis Labyrinthus, Mars

Noctis Labyrinthus is an intricate system of Late Hesperian and Early Amazonian linear troughs and rounded pits connecting the Tharsis volcanic rise and western Valles Marineris next to Martian equator. This study was focused on three light-toned deposits (LTDs) located within a trough located in the western part of Noctis Labyrinthus, centered at −6.8°N, 261.1°E, approximately 60 x 50 km in dimension and with a depth of 5 km below the adjacent plateau. These LTDs located on the floor in the central region of this trough display spectral signature of gypsum and are characterised by the widespread presence of shallow depression morphologies. We performed a morphologic and morphometric analysis of the surfaces of these LTDs through an integrated study of images available through the Reconnaissance Mars Orbiter High-Resolution Imaging Science Experiment with the aim to describe, for the first time, these landforms, and to discuss their possible origins and lithological and paleo-climatic significance. Analysis, on the basis of the characteristics of the investigated landforms and the similarities of features on Earth and Mars, and after discarding other possible origins, revealed that the examined Martian landforms have karst origin. The landform features appear to reflect water-related processes, probably due to ice melting formed during periods of ice-snow-rich deposition from the atmosphere as the result of changes in the obliquity of Mars, which could have driven the processes of dissolution or collapse on the evaporite rock. Thus, the observed karst landforms suggest a climate change and the presence of liquid water due to ice melting during the Late Amazonian age.Key words: karst, gypsum, shallow depressions, climate change, Noctis Labyrinthus, Mars

Karst Landforms in a Martian Evaporitic Dome

The Tithonium Chasma is the northern trench of the western troughs of Valles Marineris (Mars). In the eastern part of the canyon system a mountain displaying a dome shape morphology is located. According to OMEGA mineralogical data (OMEGA data orbit 531_3) and further studies the dome appears to consist of magnesium sulphate (kieserite), an evaporitic mineral also found on the Earth. Previous works highlighted the presence of karst-like landforms and morphologies that strongly resemble the evaporitic karst morphologies found on the Earth. Through the analysis of the new MRO HiRISE images we have investigated the Martian landform and the possible processes involved in their formation and shaping in great detail. The analysis carried out show that the landforms observed clearly indicate the presence of solutional processes that also acted in a selective way, highlighting that the Martian dome can be formed of dfferent materials (minerals, grain-size, ect.) with different solutional properties. The results of our observation also suggest that on the dome liquid water must have existed in the past for enough time so that the solution features we investigated could be formed

Karst landforms in an interior layered deposit within the Coprates Chasma, Mars

The Coprates Chasma forms part of the backbone of the Valles Marineris canyon system. In the westernmost part of the chasma in an embayment on the northern wall a mound of layered material rises from the chasma floor and displays a characteristic dome-shaped morphology. The mineralogical characteristics of the dome and its surroundings have been determined by analysis of the CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) data (image HRL00003752). The unit shows the clear signatures of kieserite, an evaporite mineral also found on Earth. Through analysis of the M.RO. HiRISE (Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment images) we have investigated the dome landforms and the possible processes involved in their formation and shaping in great detail. The analysis shows that the landforms observed clearly indicate the presence of solutional processes that made those karst landforms. The results of our observation also suggest that liquid water must have existed on the dome in the past for long enough for the solution features to be formed, and that the karst landforms investigated exhibit an older erosional age or shorter than the same landforms studied in a similar kieserite dome located within Tithonium Chasma, another graben of the Valles Marineris system