Występowanie bentonitów w warstwach krośnieńskich dolnych w Zagórzu koło Sanoka

Abstract

OCCURENCE OF BENTONITES IN THE LOWER KROSNO BEDS AT ZAGÓRZ NEAR SANOK (CARPATHIANS)In 11958 there was discovered, in a section of the Krosno beds exposed in the Osława valley at Zagórz (near Sanok) a tuff intercalation completely altered into bentonite. Its thickness is 40 cm. In this section there occur successively (Fig. 1): 1) black Menilite shales, 2) transition beds (thickbedded sandstones of Krosno type intercalated with shales of Menilite type) of 200-250 m. thickness, 3) Lower Krosno beds, in their lower part developed as thickbedded sandstones of 900 m. thickness, in their upper part as thickbedded sandstones and grey shales with thinbedded sandstones, more than 1000 m. thick. The younger horizons, i. e. the highest part of the Lower Krosno beds, the horizon of hard gIauconitic sandstones and the Middle Krosno beds (corrugated sandstones and grey shales), have been preserved in the area of Lesko (Fig. 1). Within the lower part of the Lower Krosno beds (700 m. above the transition beds) there occur three thin banks of calcareous Jasło shales; in the Osława valley but the two higher banks of these rocks are exposed. The bentonite intercalation occurs amidst the thickbedded sandstones, 90 In. below the middle bank of Jasło shales, almost 600 m. above the top of the transition beds (Fig. 1).