Charakterystyka petrograficzna podłoża krystalicznego bloku przedsudeckiego na południe od Wrocławia

Abstract

PETROGRAPHIC CHARACTERISTICS OF CRYSTALLINE BASEMENT OF THE FORE-SUDETIC BLOCK ON THE SOUTH OF WROCŁAWSummaryLithological and petrographic characteristics of the crystalline rocks from the 1/VIII Skrzypnik, 2/X Kobierzyce and 1/VII Biskupice bore-holes has been presented in this article. The bore-holes are located within the boundaries of the Fore-Sudetic Block and farther beyond the Block in the surrounding area on the south and south-east of Wrocław (Fig. 1). This portion of the Fore-Sudetic Blockis covered with the Cainozoic deposits. The results of investigation presented here are thought to be the appropriate information on petrographic properties of the crystalline basement rocks.An enormous attention has been drawn to structural characteristics of mica and mica-feldspar schists. The mica schists sampled from the 1/VIII Skrzypnik bore-hole are widely represented by the metamorphosed rocks occurring in amphibolic facies. Mineral assemblages and the way of forming the key mineral constituents in mica schists as well as in mica-feldspar schists sampled from the 2/IX Kobierzyce and 1/VII Biskupice bore-holes may indicate the contact zone of the greenstone and amphibolite facies. The sedimentary series originally containing clay-sandy deposits with some grauwackes which form the series in places have undergone regional metamorphism. Further development in metamorphism is closely related with unsignificantly marked sodium and potassium feldspathization and later residual deformations.