Piaskowce z warstw pogranicznych grupy brzeżnej i siodłowej w niecce chwałowickiej karbonu rybnickiego

Abstract

SANDSTONES IN BOUNDARY BEDS OF BOTH MARGINAL AND SADDLE GROUPS IN THE CHWAŁOWICE TROUGH OF RYBNIK CARBONIFEROUS Summary A series of Carboniferous strata found to occur at the boundary of marginal group (Namurian A) and saddle group (Namurian B) have been examined in the mine Jankowice (region of Rybnik, Upper Silesian Coal Basin). This is also a contact (Fig. 1) between the paralic and limnic series in this basin, separated in the region of Rybnik by an erosional gap. The paper describes macroscopic and microscopic features of the sandstones (samples A, B, C and D) observed to appear at the contact of either stratigraphical group. They differ (Tabs. II and III) in having other quartz, feldspar, chlorite, iron oxide and carbonate contents (differences in alteration degrees), as well as by their rounding degree and grain size. These features allow the present authors to draw conclusions as to the kind of the original rocks. The differences between the sands-tones of both the marginal and the saddle groups correspond to those observed to occur in the deposits between the paralic and limnic series.