Rozwój warstw krośnieńskich w niektórych obszarach Karpat Środkowych

Abstract

DEVELOPMENT OF KROSNO BEDS IN SOME REGION OF THE MIDDLE CARPATHIANS

In this paper the author has presented the results of her investigations on the facial development of the Krosno beds, observed at several localities of the Middle Carpathians. In every instance she divided the Krosno beds, on the basis of lithological and facial features, into three parts. Identical horizons of the Krosno. beds, found in different sections, are not comparable as to their thickness nor to their proportion of sandstones to shales. However, there are certain features that these horizons have in common.

In the Lower Krosno beds there prevail, as a rule, grey thickbedded, loose, calcareous sandstones with a fairly ample content of muscovite, alternating with intercalations of brown and grey shales. In strata where to a considerable extent the sandstones have been replaced by shales (see Fig. 7, horizon I), the sandstones still maintain their features.

In the Middle Krosno beds there appear chiefly corrugated and platy sandstones very much harder than those in the Lower Krosno beds; they are accompanied by grey calcareous shales. The proportion of sandstones to shales varies. Generally speaking, these beds are the ridge-forming element.

The Upper Krosno beds are predominantly a complex of shales with a scanty number of thin sandstone intercalations. In the Mokre section only (Fig. 7), these beds are developed, at their top, as hard thickbedded platy sandstones.

Within the range of the Krosno beds the author has identified intercalations of Jasło shales (laminated limestones), developed in one or two horizons, as well as diatomite rock (Wysoka Strzyżowska; Fig. !?, horizon HI) and tuffite intercalations (Tyrawa Wołowska; Fig. 6, horizon III).