The Caves of the Contact Karst of Beka and Ocizla, the SW Slovenia

Abstract

Beško-Ocizeljski jamski sistem je razvit v območju kontakta med paleocenskim apnencem in eocenskim flišem na nadmorski višini 350 m na jugozahodu Slovenije. Plasti apnenca generalno vpadajo proti NW, najizrazitejše prelomne strukture so v dinarski in prečnodinarski smeri. S fliša na kontakt z apnencem pritekajo trije večji in en manjši potok, ki ponikajo v apnenec. V jamski sistem se povezujejo Ocizeljska jama, Blažev spodmol, Maletova jama s slapom, Jama z naravnim mostom, Jurjeva jama v Lokah in Jama S-4/Socerb od katerih vhodi v štiri jame delujejo kot občasen ponor. Skrajna vhoda sta drug od drugega oddaljena 500 m. Voda se v sistemu istočasno pretaka na različnih nivojih in drenira proti Boljuncu. Za razvoj jamskega sistema, generalne smeri jamskih rovov in pretakanje vode v sistemu, je najpomembnejši sistem vzporednih tektonskih ploskev z vpadom 220/50-80.

The cave system of Beka-Ocizla is developed in the area of contact between Palaeocene limestone and Eocene flysch at 350 m a.s.l. in south-western Slovenia. The beds of limestone could generally be traced in the direction towards NW; the most distinct tectonic structures are in the Dinaric direction and transversely to the Dinaric direction. Three bigger streams and one smaller flow from the flysch on the contact with limestone, which sink into the limestone. The following caves are connected to the cave system: Ocizeljska jama, Blažev spodmol, Maletova jama s slapom, Jama z naravnim mostom, Jurjeva jama v Lokah and Jama S-4 / Socerb; the entrances of four of those caves function as occasional ponors. The least close entrances are 500 m away from each other. The water in the system simultaneously flows on various levels and drains in the direction of Boljunec. The system of parallel fault planes with dip 220/50-80 is the most important for the development of the cave system, the general direction of the caveʼs passages and the flow of water in the system.