O piaskowcach zsylifikowanych z obszaru Bieszczad

Abstract

ON SILICIFIED SANDSTONES FROM THE BIESZCZADY RANGE Summary In the Bystry fold, situated south of Baligród (Bieszczady Range, Flysch Carpathians), silicification process has been observed to occur in certain sandstone horizons, mainly in the Upper Istebna and the Ciężkowice sandstones. The process begins in cementing material and in irregular fractures filled in with silica that appears as more or less developed quartz crystals. Similar silicified sandstones are reported to occur in the pre-Dukla zone, SEE of Bystry, in the vicinity of Dołżyca. Due to the silicification process the sands tones here considered are characterized by a considerable compactness which is their distinguishing feature, in contrast to the similar sandstones found to occur in the other areas of the Flysch Carpathians. They reveal also different technical properties, among others a high compression strength. The process of silicification is contemporaneous with the arsenic mineralization (realgar, auripigmentum) that has previously been ascertained to appear in the Bystry fold. This process and the arsenics mineralization should be related to the low temperature hydrothermal solutions which are the result of the Young-Tertiary volcanic activity within the Internal area of the Carpathian arc.