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Full-Text Articles in Physical Sciences and Mathematics
Karst In Siliceous Rocks - Karst Landforms And Caves In The Auyàn-Tepui Massif (Est. Bolivar, Venezuela), Leonardo Piccini
Karst In Siliceous Rocks - Karst Landforms And Caves In The Auyàn-Tepui Massif (Est. Bolivar, Venezuela), Leonardo Piccini
International Journal of Speleology
During the expedition "Tepuy 93", six caves were explored in the precambrian quartzites of Roraima Group, in the Auyan-tepui massif. One of this caves reaches the depth of 370 m and a development of almost 3 km; its name is “Sima Auyan-tepui Noroeste” and it is currently the deepest cave in the world discovered in siliceous rocks The geological and morphological study of this cave has underlined again the importance of deep solutional weathering, along the network of fractures for the formation of caves in siliceous rocks. The different formation stages of the big superficial shafts, called “simas” were observed …
Karst In Siliceous Rocks: The Speleothem Medium Of Finger Flutings And Its Isotopic Geochemistry, Robert G. Bednarik
Karst In Siliceous Rocks: The Speleothem Medium Of Finger Flutings And Its Isotopic Geochemistry, Robert G. Bednarik
International Journal of Speleology
The isotopic geochemistry relating to the re-precipitation of calcite in caves is considered, in terms of its theory, natural manifestations, and relationship with questions of radiometric dating of carbonate speleothems. Specific forms of’ such deposits are considered, together with the various modification processes they are subjected to. More specifically, particular forms of rock art found within, as well as on or under such deposits are examined, such as finger flutings commonly found in caves of Europe and Australia. Some of the variables relating to their occurrence are elucidated, their preservation and possible dating is reviewed in the light of these …
Paleokarst Of The Bohemian Massif In The Czech Republic: An Overview And Synthesis, Pavel Bosàk
Paleokarst Of The Bohemian Massif In The Czech Republic: An Overview And Synthesis, Pavel Bosàk
International Journal of Speleology
Paleokarst of the Bohemian Massif on the territory of the Czech Republic developed as polygenetic and polycyclic forms with several phases of fossilization and rejuvenation depending on tectonic phases and deep chemical weathering. Paleotectonic period (pre-Permian in general) was characterized by evolution of relatively minor depositional and local paleokarsts. Neotectonic (platform) period (post-Permian) favoured the prolonged karst evolution of interregional paleokarst in two karst periods and several more or less distinctly separated karst phases.
The Classification Of Cave Minerals And Speleothems, Carol A. Hill, Paolo Forti
The Classification Of Cave Minerals And Speleothems, Carol A. Hill, Paolo Forti
International Journal of Speleology
The classification scheme of Hill and Forti, as used in the second edition of Cave Minerals of the World, is presented as a "practical" solution to the classification of cave minerals and speleothems. Classification and naming of cave minerals is by crystal class and follows nomenclature approved by the International Mineralogical Association. Classification of speleothems is based on morphology and whatever is known about origin, with division of speleothems into types, subtypes, and varieties. It is proposed that new speleothem types, subtypes, and names be approved by a UIS Commission of cave mineralogists.
On Some Cave Minerals From Northern Norway, Bogdan Petroniu Onac, Stein-Erik Lauritzen
On Some Cave Minerals From Northern Norway, Bogdan Petroniu Onac, Stein-Erik Lauritzen
International Journal of Speleology
The present paper aims to point out the results of 31 samples from some Norwegian caves that have been analysed with respect to their mineralogical composition. Identification of the minerals was done by X-ray diffraction, thermal, infrared spectroscopy and scanning electron microscopy. Seventeen minerals were identified belonging to 4 groups: carbonates, sulphates, oxides-hydroxides and silicates.