In the Lessini Mountains, the southernmost prealpine area in the Veneto region, thousands of caves are found, many of which have been extensively studied from the biological point of view. Numerous ...studies have been carried out on taxonomic and biogeographic aspects over the last hundred years. Two caves, in particular, have been found to be extremely rich in species adapted to life in subterranean environments. These are the Arena Cave in the Monti Lessini Veronesi and the Buso della Rana cave system in the Monti Lessini Vicentini. The two caves have extremely different development: Arena Cave is about 100 meters in length, and the Buso della Rana-Pisatela cave system is more than 37 km in length. Despite this huge difference in size, they both have the highest number of subterranean dwelling species in northern Italy (16 troglobionts and 8 stygobionts in Arena Cave, and 7 troglobionts and 11 stygobionts in the Buso della Rana-Pisatela cave system).
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The Tatarka bauxite deposit on the territory of the Russian Federation was formed as a result of sedimentation of the products of denudated lateritic weathering crusts of amphibolites in ...contact-karst depressions. Detailed mineralogical studies of bauxites made it possible to reconstruct reliably the conditions for their formation. As it turned out, the initial rocks and rocks, weathered before, have been denudated due to the close location of the areas of alimentation and accumulation. At the same time, chemical processes have been continued in karst depressions. For the first time, the presence of nanoparticles of amorphous aluminum oxide was revealed in contact-karst bauxites. This specific feature of the form of alumina precipitation is associated with the subsequent cessation of lateritization and their attenuation with depth. The presence of amorphous aluminum monohydrate must be taken into account when choosing a scheme for bauxite enrichment.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The explored area is about 4 km east of Slunj town at the region known as Kordun Karst. This location stipulated the specific condition for the formation of the speleological objects in the south ...area of Grabovac Valley. The Grabovac Stream flows from the north to the south through the Grabovac Valley connected to the canyon of the river Korana. Partially the Grabovac Stream flows underground. In this area in the period of years 2000 and 2001 a member of Speleological society Karlovac (Karlovac, Croatia) explored three caves. The biggest is Ponor pod Kremenom Cave with total length of the channels of 1019 m. The underground part of the Grabovac Stream flows through its channels. In the south of the dry part of the valley there are two caves: Gornja Barićeva (260 m long) and Donja Barićeva (26 m long). Morphological characteristics indicate the dynamics of the formation of the cave system under the influence of the allogenic water. They are the result of the corrosion and erosion caused by the water of the underground part of Grabovac Stream during several phases. These tree caves are parts of one system in sense of speleogenesis. Six basic phases of the formation of the speleological objects can be established. The aim of this paper is to give the basic theses about the morphogenesis of these caves, particularly in relation to their geomorphological position.
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Several types of contact karst are found within the Slovenian karst, but the most common is the ponor type, which usually develops at boundaries between flysch and limestone. The most extensive ...contact of this type is in the area of Matarsko podolje in western Slovenia and in its northern extension, Vrhpoljska brda. In this contact karst area two types of alluvial fans appear on carbonate bedrock. Members of the first type are ordinary alluvial fans with active alluvial processes where flysch derived sediment covered limestone surface in a distinct fan shape. The other type, described as relict alluvial fans, is fan-shaped features preserved in the carbonate bedrock. These essentially bedrock landforms developed as a result of the gradual removal of pre-existing alluvial fan cover and the concurrent but non-uniform chemical denudation of the underlying carbonate bedrock. Geomorphologic and morphometric description of alluvial fans and relict alluvial are provided in the article and mechanisms of relict alluvial fans formation are discussed.
Several types of contact karst are found within the Slovenian karst, but the most common is the ponor type, which usually develops at boundaries between flysch and limestone. One of these types is in ...the area of Vrhpoljska brda. In this contact karst area two types of alluvial fans appear on carbonate bedrock. Members of the first type are ordinary alluvial fans with active alluvial processes where flysch derived sediment covered limestone surface in a distinct fan shape. The other type, described as relict alluvial fans, is fan-shaped features preserved in the carbonate bedrock. These essentially bedrock landforms developed as a result of the gradual removal of pre-existing alluvial fan cover and the concurrent but non-uniform chemical denudation of the underlying carbonate bedrock. Geomorphologic and morphometric description of alluvial fans and relict alluvial are provided in the article and mechanisms of relict alluvial fans formation and transformation are discussed.
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The paper presents the main characteristics of the limestone ridge Dzevrinska Greda in north-eastern Serbia, which is a typical example of stripe karst (sub-type of contact karst). Dimensions and ...elongated shape of the limestone outcrop, as well as its position in relation to the surface drainage network, have led to formation of a number of short through gorges. The conditions of their formation and certain morphological features pointing to phases of their development are discussed in the paper. One of the indicators was the analysis of cave passages positions, which in most cases points to cave development in phreatic conditions. This means that the incision of through gorges is more recent than speleogenesis.
U radu su predstavljene osnovne odrednice krecnjackog grebena Dzevrinska greda u severoistocnoj Srbiji, koji je tipski primer pojasnog karsta (podvrsta kontaktnog karsta). Dimenzije i izduzeni oblik krecnjackog izdanka, te njegov polozaj u odnosu na povrsinsku recnu mrezu, doveli su do formiranja veceg broja kratkih klisura-probojnica. Razmotreni su uslovi njihovog formiranja, te morfoloske odlike koje ukazuju na pojedine faze u njihovom razvoju. Jedan od indikatora za to bila je analiza polozaja speleoloskih objekata u klisurama, koja u vecini slucajeva ukazuje da su pecine formirane u freatskim uslovima, tj. da je usecanje probojnica recentnije od speleogeneze.
Several types of contact karst are found within the Slovenian karst, but the most common is the ponor type, which appears between flysch and limestone. The most extensive contact of this type is in ...western Slovenia, in the area of Matarsko podolje, where a variety of typical contact karst depression features can be found. Relict alluvial fans on contact karst are the result of the gradual denudation of alluvial fans, and the influences of alluvial fans. Geomorphologic features and processes on alluvial fans, and the influences of alluvial fans on the development of local karst have been investigated in detail.
Several types of contact karst are found within the Slovenian karst, but the most common is the ponor type, which usually appears between flysch and limestone. The most extensive contact of this type ...is in western Slovenia, in the area of Matarsko podolje, where a variety of typical contact karst depression features can be found. In the northwestern part of Matarsko podolje two types of alluvial fans occur. One alluvial fan has an active process of alluvial sedimentation on its surface and is distinct in shape, just like alluvial fans in fluvial geomorphic systems. The other type represents relict alluvial fans on contact karst. They are fan-shaped surface features in carbonate bedrock. Their formation is a result of the gradual removal of alluvial cover and the chemical denudation of carbonate bedrock on areas that were covered by alluvial fans. Geomorphological features and processes on alluvial fans, and the influences of alluvial fans on the development of contact karst have been investigated in detail.
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