Zur geochemie der sedimentite des Permosiles im Südteil der D.D.R.

Abstract

Since the beginning of this century the late Variscan red bed formations were said to be the source of the metals of the Upper Permian “Kupferschiefer”-mineralization. Up to the last years there was a lack of regional investigations of the geochemistry of these rocks. To prove the above mentioned theory, we determined the Fe-, Corg-, S-, Cu-, Pb-, Zn-, Ni-, Co-, Mn-, B-, Ba-, Sr-, Rb-, V-, Cr-, Ti-, Zr- and Sn- contents of more than 2000 samples of red, grey and bleached psephitic, psammitic and pelitic sedimentary rocks and of some coal samples. In all investigated rock types the average Fe-, Ni- and Cr-contents are higher in the red-coloured rocks than in the grey and bleached ones; the average B-, Rb- and Ba-contents are equal in the red, grey and bleached rocks; the average Corg-, S-, Cu-, Pb- and Zn-contents are higher in the grey rocks than in the red-coloured ones. Only in the last group of elements the average contents are higher than the planetary Clarke of each rock type. Special investigations were made about geochemical facies, distribution of base metals, diagenetic and epigenetic influences on the distribution of base metal mineralizations and the source of elements. The late Variscan volcanism was proved to be the main source of elements in the red bed formations. The sedimentary and magmatic rocks of the molasse stage are Pb-specialized, therefore the Central European Variscan belt forms a lead province.