National Repository of Grey Literature 5 records found  Search took 0.00 seconds. 
Valley incision in the Nízké Tatry Mts. (Slovakia) estimated based on paleomagnetic and radiometric cave sediment datings
Kadlec, Jaroslav ; Bella, P. ; Čížková, Kristýna ; Granger, D. E. ; Hercman, H. ; Holúbek, P. ; Chadima, Martin ; Orvošová, M. ; Pruner, Petr ; Schnabl, Petr ; Šlechta, Stanislav
Up to eleven horizontal cave levels occur at different altitudes in Jánska, Demänovská and Mošnická karst valleys in the Nízke Tatry Mts. Most of the caves are filled with allochthonous sediments transported from the area formed mostly by granite. The cave levels were filled with fluvial sediments in dependence on the valleys incision caused by Neogene and Pleistocene uplift of the mountain range. The fluvial sediments are intercalated with, or capped, by flowstone layers in the caves. The paleomagnetic polarities measured both in clastic and chemogenic sediments indicate the age of deposition. Based on obtained polarity data we are able to distinguish cave sediments deposited during the Brunhes, Matuyama and Gauss chrons. The paleomagnetic interpretation was partly verified by U-series datings of flowstones preserved in the sedimentary sections. Except for the horizontal cave levels located in the karst valleys, additional large cave systems were found at extremely high altitudes in the Nízke Tatry Mts. 600–700 m above the lowest horizontal cave level.
Miocene-Pliocene age of cave Snežna Jama na Raduhi, Southern Alps, Slovenia
Mihevc, A. ; Horáček, I. ; Pruner, Petr ; Zupan Hajna, N. ; Čermák, Stanislav ; Wagner, Jan ; Bosák, Pavel
Snežna jama cave is 1,600 m long horizontal cave at about 1,500 m a.s.l. in Raduha Massif (Kamnik-Savinja Alps) rich in cave deposits (both allogenic sediments and massive flowstones). The cave size, shape and deposits show (1) formation of the cave in different conditions, and (2) its substantial age. A 4.8 m deep pit was excavated in allogenic sediments. Samples were taken both for palaeomagnetic analysis and palaeontological screening. Sediments consist of rhythmically arranged layers deposited in phreatic conditions. Fragments of rodent teeth and a well-preserved molar of genus Baranomys were identified. Fossil remains indicate mammalian zone MN 16 and MN 14. A high-resolution palaeomagnetic analysis revealed total of 3 principal normal polarized and 2 principal reverse polarized magnetozones. If we accept the palaeontologic calibration, the deposition took place within Gauss and Gilbert chrons, from about 2.6 to more than 5 Ma. Long sedimentation period is in concordance with the cave rocky relief that shows phreatic and epiphreatic morphology and predates the main uplift of the area for about 900 m.
The study of sediments and speleothems in the Zbrašov Aragonite Caves
Bosák, Pavel ; Šlechta, Stanislav ; Hercman, H. ; Pruner, Petr
The numerical dating of hydrothemal speleothems (doughnuts) from locality At Crocodile gave older data than was published in the literature: 123 to 127 thousand years (with range 108 to 144 thousand years). Speleothems crystallized in the time of climatic optimum of the last interglacial period (Eemian) corresponding to the marine isotope stage (MIS) 5e. Clastic sediments from excavations in the area At Crocodile show normal paleomagnetic polarity in all samples with nearly recent magnetic field directions. Studied sediments cover block of hydrothermal speleothems fallen from the wall and therefore they must be younger than 108 thousand years.
Age and genesis of sediments in the Ochozská Cave
Kadlec, Jaroslav ; Pruner, Petr ; Venhodová, Daniela ; Hercman, H. ; Nowicki, T.
Large section in cave deposits are exposed in the Ochozská Cave in southern segment of the Moravian Karst. The study of the genesis and age of these cave deposits poses a clue to the reconstruction of development of the Ochozská Cave and of local paleohydrographic history. The time of deposition was determined by probably deposited during the Middle and late Pleistocene in the cave.
Dating of cave sediments and reconstruction of karst morphology of the Nízké Tatry Mts
Kadlec, Jaroslav ; Danišík, M. ; Hercman, H. ; Pruner, Petr ; Chadima, Martin ; Schnabl, Petr ; Šlechta, Stanislav ; Grygar, Tomáš ; Granger, D.
The paleomagnetic polarities were measured both in clastic and chemogenic cave sediments preserved in eleven horizontal cave levels occur at different alitudes in the Jánska, Demänovská and Mošnica karst valleys in the Nízké Tatry Mts. Based on the obtained polarity data were are able to distinguish cave sediments deposited during the Brunhes, Matuyama and Gauss chrons. The stratigraphic interpretation was partly verified by U-series datings of speleothems preserved in the sedimentary sections. Except for the horizontal cave levels located in karst valleys, additional cave systems were formed at extremly high alitudes in the Nízké Tatry Mts. Preliminary data show predominantly reverse paleomagnetic orientations in fluvial activity in these caves and deposition of clastic sediments during Gilbert Chron.

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