Lithostratigraphic Characteristics of the Intermittent Pivka Lakes Region and Matijeva Jama Cave Estavelle

V prispevku opisujeva tipične značilnosti kamnin, ki jih zasledimo na področju presihajočih Pivških jezer. V zgornje krednih apnencih sta se oblikovali dve značilni kraški jami: Matijeva jama, ki se danes kaže kot estavela in Trnska jama s številnimi znaki pogostega in izdatnega nihanja gladine podzemeljske vode. Predstavljava nekatere nove izsledke raziskav.This article describes the typical characteristics of rock found in the area of the intermittent Pivka lakes. Two characteristic karstic caves formed in Upper Cretaceous limestone: Matijeva jama, which appears as an estavelle today, and Trnska jama, vvith several old and recent signs of frequent and plentiful fluctuation in groundwater level. Several new research results are presented.