Reconstruction of palaeoflow and depositional dynamics from the Merjasec unroofed cave, Laze Plain (central Slovenia)

Miklavc, Primož (author), Lipar, Matej (author), Šušteršič, France (author), Šmuc, Andrej (author)

Sparsely preserved unroofed cave deposits are ancient remains of cave systems. The Merjasec unroofed cave is a perfect example of poorly preserved cave deposits where conventional sedimentological study revealed a greater potential for the reconstruction of local to regional palaeoenvironmental conditions. Cave deposits are characterised by polymictic conglomerates, pebbly sandstones and flowstone belonging to five distinct sedimentary facies. Sedimentary features indicate deposition of channel-related bedforms in a narrow cave-connecting conduit, activated only during extreme pulsating floods under epiphreatic conditions. In this sense, it mimics the current hydrology of the regional system and shows that the hydrological history of the cave system is strongly dependent on climatic conditions. Moreover, this study demonstrates a methodological approach that can be successfully applied to similary exposed cave deposits elsewhere, showing that even fragmentary or eroded remnants, when analysed in detail, can significantly contribute to understanding of karst palaeohydrology.

• Language: English
• Keywords: karst, denuded cave, clastic cave deposits, facies, fluvial, depositional dynamics, palaeoenvironment
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: str. 30-45
• Numbering: ǂLetn. ǂ65, ǂšt. ǂ2
• PID: 20.500.12556/RUL-178401
• UDC: 551.435.84:551.3.051(497.4)
• ISSN on article: 1581-6613
• DOI: 10.3986/AGS.14446
• COBISS.SI-ID: 252196867
• Publication date in RUL: 30.01.2026

Record is a part of a journal

• Title: Acta geographica Slovenica
• Shortened title: Acta geogr. Slov.
• Publisher: Geografski inštitut Antona Melika ZRC SAZU, Založba ZRC, Slovenska akademija znanosti in umetnosti
• ISSN: 1581-6613
• COBISS.SI-ID: 124775936

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Title: Rekonstrukcija paleotoka in dinamike zapolnjevanja brezstrope jame Merjasec, Laški ravnik (osrednja Slovenija)

Abstract

Redkeje ohranjeni sediment brezstropih jam so ostanki starejših jamskih sistemov. Brezstropa jama Merjasec je odličen primer slabo ohranjenih jamskih sedimentov, kjer so konvencionalne sedimentološke študije pokazale velik potencial za rekonstrukcijo lokalnih do regionalnih paleookoljskih razmer. Jamske sedimente predstavljajo polimiktični konglomerati, prodnati peščenjaki ter sige in so organizirani v pet različnih sedimentnih faciesov. Sedimentne značilnosti kažejo na odlaganje v ozkem, povezujočem kanalu aktiviranem le med ekstremnimi pulzirajočimi poplavami pod epifreatičnimi pogoji. V tem smislu posnema sedanjo hidrologijo regionalnega sistema in kaže, da je hidrološka zgodovina jamskega sistema močno odvisna od podnebnih razmer. Poleg tega ta študija prikazuje metodološki pristop, ki ga je mogoče uspešno uporabiti za podobno razgaljene jamske sedimente drugje, in kaže, da lahko celo fragmentirani ali erodirani ostanki, če jih podrobno analiziramo, pomembno prispevajo k razumevanju kraške paleohidrologije.

• Keywords: kras, brezstropa jama, klastični jamski sedimenti, faciesi, fluvialno, dinamika odlaganja, paleookolje