Naslov
Geological profile of the Lubuška pit, Northern Velebit, Croatia

Autori
Kurečić, Tomislav ; Sudar, Vedran ; Brčić, Vlatko

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
26th International Karstological School "Classical Karst" - Show caves and science: abstracts & guide book / Prelovšek, Mitja - Postojna : ZRC Publishing, 2018, 76-76

ISBN
978-961-05-0090-2

Skup
26th International Karstological School “Classical Karst”: Speleology

Mjesto i datum
Postojna, Slovenija, 18.06.2018. - 22.06.2018

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Velebit Mt., Lubuška pit, geological profile

Sažetak
The Lubuška pit is located in the area of the Strict Reserve “Hajdučki and Rožanski kukovi“ within the borders of the Northern Velebit National Park. Its entrance is situated at 1495 m above sea level. During previous speleological expeditions the pit has been explored to a depth of 508 m. No detailed geological surveys have been carried out so far, except for scattered observations of structural elements at the shallow parts of the pit. The main aim of the recent geological survey during "Lubuška jama 2017" expedition is to construct of a schematic geological profile of the pit. Two lithological units were observed ; the Velebit (Jelar) breccia and well stratified Jurassic carbonate complex represented by various limestone types. Sampling was carried out across the whole profile below the depth of 240 m, which is also the depth of the contact zone between the Velebit breccia above and the underlying well stratified carbonate complex. Rocks and cave sediment samples were collected at 11 locations throughout the profile of the pit at morphologically specific parts, to ascertain the precise depth of sampling. The contact between the breccia and the carbonate complex has not been precisely established, but most likely it is a tectonic contact. In addition to the sampling, preliminary structural measurements were performed. According to petrographic analysis of rock samples the entire carbonate complex below the Velebit breccia chronostratigraphically belongs to the Callovian-Oxfordian. The specimens include carbonate breccia and limestone variants such as bioclastic wackestone to packstone, micrite limestones and dolomitized limestones. Also, two basic types of clastic sediments were observed: a red silty-clay that fills the cracks in the walls of the channels and stream transported sandy-clay silt deposited next to the siphon lake. The construction of the schematic geological profile of the Lubuška pit is a contribution to the understanding of the geological structure of Hajdučki kukovi area and the broader area of Northern Velebit.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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