Zagadnienia strukturalne podłoża górnego karbonu w niecce Słupca

Abstract

STRUCTURAL PROBLEMS OF THE UPPER CARBONIFEROUS SUBSTRATUM IN THE SŁUPIEC TROUGHSummaryIn the Nowa Ruda region, Lower Silesia, both the Wałbrzych and Žacler beds represent the payable Upper Carboniferous formations. The Žacler beds, that belong to Westphalian A and B, are found to occur in the longitudinal sedimentary troughs characterized by a NNE-SSW direction of axes, as for example the Słupiec trough. This was here the southernmost Westphalian sedimentary basin. The substratum of the Słupiec trough is built up of gabbros and diabases, as well as of gabbro and diabase conglomerates and argillites of Pre-Cambrian age. The sedimentary formations originated due to the weathering processes and the local continental sedimentation. Most probably, their age is Upper Devonian. In the Lower Westphalian, the gabbro-diabase massif slowly subsided. Within its western slope, phytogenic sedimentation began characterized by an inflow of clastic material from the adjacent area. At first, a series of clay shales was formed, among them also refractory shales. The thickness of this series amounts to about 35 metres. The shales are overlain with the Žacler beds with some coal measures. The thickness of these beds is from 50 to about 120 m. A difference in the thickness of the shale series was a result of the fact that the sedimentation took place within the area of a highly rough substratum. The difference in the thickness of the Žacler beds was additionally due to the synsedimentary movements at the Upper Vestphalian time. When examining the distribution of the thickness in the shale series and the contents of clastic material in these shales, the author aimed at reconstructing either pre-Westphalian or early Westphalian sedimentary surface. The results of his work are shown on the structural map of the Upper Carboniferous, substratum (Fig. 4). Based on these researches, the author selected within the trough some perspective areas of hard coal and refractory shale occurrences.