Bentonitowe utwory karbońskie na skrasowiałych wapieniach dewonu w rejonie Terebina k. Hrubieszowa

Abstract

CARBONIFEROUS BENTONITE DEPOSITS ON KARSTIFIED DEVONIAN LIMESTONES IN THE TEREBLIN AREA NEAR HRUBIESZÓW Summary The Terebin IG-5 borehole was made in overhanging limb of the Włodzimierz fault in the vicinities of Hrubieszów. It penetrated bentonite deposits in the top of Frasnian, beneath Upper Visean. Frasnian is here represented by eroded limestones developed in biolithic and biomicritic facies. In these limestones there were found small fissures infilled with collapse breccia and other, filled with clay-sandy tufaceous material consisting of rounded quartz grains derived from the Hulcza Formation (uppermost Devonian) and claystones with kaolinite-chamoisite pisolites and pyrogenic material (tuffs) of Lower Carboniferous. Limestone deposits are overlain by a cover of weathered bentonized ash tuffs which were deposited in shallow water reservoir. These deposits are dated at the Early Carboniferous (Tournisian - early Visean). They are related to the oldest karst processes hitherto recorded in Poland.