Miedzionośność utworów spągowych cechsztynu na monoklinie przedsudeckiej i peryklinie Żar oraz możliwości dalszych poszukiwań

Abstract

THE COPPER-BEARING AND PERSPECTIVE OF FURTHER SEARCH IN BASAL ZECHSTEIN ROCKS IN THE FORE-SUDETIC MONOCLINE AND ŻARY PERICLINE Summary Prospecting and research works on copper ores, carried out in the Lower Silesia by the Geological Institute since 1959, made it possible to trace Tertiary subcrops of the Zechstein from Wołczyn on the east to the state boundary on the west, i.e. at 250 km distance. The extent of Zechstein deposits in the areas of the Fore-Sudetic Monocline and Żary pericline was delineated and degree of their mineralization was analysed. In the Lublin-Sieroszowice deposit area the deposit series is represented by three lithological types: sandstone, shaly and carbonate types which are the main collectors of Cu-Pb-Zn compounds. Numerous drillings made outside the Lublin-Sieroszowice deposit area by the Geological Institute and Petroleum Prospecting Enterprise showed the presence of the series throughout vast areas of the Fore-Sudetic zone. All the three lithological types were found in boreholes made in the areas of the Żary pericline (boreholes P-3, P-5, P-9 and P-11) and Fore-Sudetic Monocline (Sława IG-1 and M-1 Lipowiec) after 1974. In these boreholes are mineralized uppermost parts of sandstone series and shaly series whereas carbonate series contains only small amounts of Cu-Pb-Zn sulfides. The mineralization of Pb-Zn-Cu type predominates in the area of the Żary pericline whereas that of the Cu-Pb-Zn type (borehole Sława IG-1) and Pb-Zn-Cu type (borehole M-1) predominates in the Fore-Sudetic Monocline. The copper-bearing shale horizon is replaced by calcareous or dolomitic grey marls with brown spots (so-called rote Fäule) in some parts of the Fore-Sudetic Monocline and Żary pericline. In these deposits hydrated iron oxides appear whereas sulfide mineralization is lacking. Vertical and horizontal zonality in distribution of Cu-Pb-Zn mineralization was found in the Groddziecko and Złotoryja Basins and the Lublin-Sieroszowice deposit area. The richest copper mineralization was found in direct proximity of oxidation zone which passes into the lead and, subsequently, zinc zone. Detailed analysis of lithological, stratigraphic, geochemical, facies, paleogeographic, tectonic, genetic and economic-technical data showed that the most perspective areas of occurrence of Zechstein formation include the Lower Silesia and especially the Czeklin-Żarków-Jany region and southern part of the Żary pericline, the Sława and Kożuchów regions in the western part of the Fore-Sudetic Monocline, and the Laskowo-Borzęcin-Radziądz, Wierzchowice-Bogdaj-Sulmierzyce and Mirków regions in the eastern part of the Monocline. Interesting mineralization of the Cu-Pb-Zn or Pb-Zn-Cu and Pb-Zn types was found in single boreholes in these areas.