Age of Dinaric karst cave sediments in SW Slovenia

0380024 - GLÚ 2013 RIV SI eng C - Konferenční příspěvek (zahraniční konf.)
Zupan Hajna, N. - Mihevc, A. - Pruner, Petr - Bosák, Pavel
Age of Dinaric karst cave sediments in SW Slovenia.
Man and Karst 2011 : Proceedings. Sarajevo: Fakultet drušstvenih znanosti dr. Milenko Brkic Sveučiílišta Hercegovina, 2012 - (Lučic, I.; Mulaomerovič, J.), s. 13-28. ISBN 978-9958-0910-0-1.
[Man and Karst 2011. Bijakovici- Medugorje (SI), 13.10.2011-16.10.2011]
Grant CEP: GA AV ČR IAA300130701; GA MŠMT(CZ) MEB090619
Výzkumný záměr: CEZ:AV0Z30130516
Klíčová slova: age of the karst * cave sediments * paleomagnetic dating * Dinaric karst * karst (Slovenia)
Kód oboru RIV: DB - Geologie a mineralogie

The question of karst evolution in Slovenia, the age of karst surfaces and speleogenesis and, consequently, the rates of processes has been an important issue in most of previous karst studies and syntheses. The majority of dating of karst sediments has been carried out in south-western Slovenia (i.e. in the north-western part of the Dinaric karst), which is known as the Kras. Eocene flysch rocks are the last marine deposits preserved in the geologic record. The first estimates of the age of the karst in the western Slovenia were made by geologists and karst geomorphologists. They suspected that the karst started to evolve during Pliocene times and they defined a pre-karst phase, when rivers were flowing across the karst surface and deposited fluvial sediments, and the karstification phase when rivers began to sink at the edges of the karst. The application and interpretation of palaeomagnetic analysis and magnetostratigraphy of the cave sediments, both clastic and chemogenic, which began on Kras in 1997, suggested substantial changes in the lower limit ages of cave fill deposition. More than 2000 samples were taken and analysed from different localities of Slovenian Dinaric karst. Magnetostratigraphy data and the arrangement of obtained magnetozones often indicated ages of sediment fill over 1.77 Ma and even over 5 Ma. Results were in some sites calibrated by Th/U, palaentological and geomorphological analyses. Calibrated data contributed to reconstruction of speleogenesis, deposition in caves, and indirectly to evolution of karst surfaces and succession of tectonic movements. From the age of the cave sediments follows that the caves and karstification have to be even older and we can conclude that the evolution of caves in Slovenia took part within one post-Eocene karstification period.
Trvalý link: http://hdl.handle.net/11104/0210852