Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
Geochronological and geochemical research of spelean sinters from the Bohemian Karst: New results
Abstract
Radiocarbon and U/Th dating methods have been applied to the samples of cave sinters from the Koněpruské jeskyně Cave, the Bohemian Karst. The radiocarbon dating shows that most, if not all, the sinters are generally older than 21 000 years Based on the U/Th method, the age of the youngest massive laminated flowstone is only about 72 000 years. Stratigraphically oldest carbonate-siliceous popcorn sinters ("Koněprusy rosettes) yielded the age of about 227 000 years. The latter determination much contradicts the prevailing point of view, based on vague paleontological and geomorphological evidence, that the early sinters and the caves in general originated durinf the Tertiary period. Uranium concentrations in the cave sinters are very low and range, regardless of their stratigraphical position, between 0.06 and 1.26 ppm. Thus, the earlier views about the "uranium-bearing" sinters of the Bohemian Karst must be considered with certain precaution.
