ZMIENNOŚĆ MINERALIZACJI KRUSZCOWEJ W SPĄGOWYCH UTWORACH CECHSZTYNU NA GRANICY STREFY UTLENIONEJ I REDUKCYJNEJ W ZACHODNIEJ CZĘŚCI ZŁOŻA POLKOWICE

Abstract

VARIABILITY OF ORE MINERALIZATION IN THE LOWERMOST ZECHSTEIN ACROSS THE REDOX INTERFACE IN THE WESTERN PART OF THE POLKOWICE DEPOSITAbstract. A full-scale investigation into variability of ore mineralization at the contact between oxidized and reduced zone in the copper-bearing Zechstein series was performed. Results of the studies were obtained on the basis of archival boreholes located in the western part of the Polkowice mining area, proximal to the Fore-Sudetic Block. Detailed microscopic observations enabled to identify the following ore minerals: chalcocite, covellite, digenite, tennantite, bornite, chalcopyrite, cobaltite, skutterudite, nickeline, rammelsbergite, pyrite, galena, sphalerite and marcasite. Microscopic observations allowed determining some features of host sediments (textures and structures) and establishing relations between constituents of rocks. Petrographic analysis of thin-sections also allowed describing the lithology of the rocks. The variability of ore mineralization in the boreholes indicates the occurrence of high-grade copper ores (mainly disseminated mineralization) above the oxidized zones, and the presence of submicroscopic gold in oxidized rocks.