WIEK MINERALIZACJI KRUSZCOWEJ W ANALIZIE DOJRZAŁOŚCI MATERII ORGANICZNEJ ŁUPKU MIEDZIONOŚNEGO I JEGO POWIĄZANIE Z TEKTONIKĄ POŁUDNIOWEJ CZĘŚCI MONOKLINY PRZEDSUDECKIEJ

Abstract

THE TIMING OF ORE MINERALIZATION BASED ON THERMAL MATURITY MODELLING OF KUPFERSCHIEFER STRATA AND ITS RELATION TO TECTONICS OF SOUTHERN PART OF THE FORE-SUDETIC MONOCLINE (SW POLAND)

Abstract. The timing of Kupferschiefer ore mineralization with respect to stratigraphy is a matter of broad debate in the literature. The paleomagnetic dating of hematite, K-Ar ages of diagenetic illite, as well as the age of thucholite and metallic lead place the ore mineralization within the time frame of Late Permian to Early Triassic untill the Cretaceous period. To resolve the controversy about timing of ore formation with respect to organic matter alteration, the maturity of organic matter was numerically modelled, based on an irreversibility of its thermal transformation. The maturity analyses using BasinMod numerical modelling indicated that the Kupferschiefer organic matter was thermally mature within the low-temperature thermogenic processes (0.5 to 1.3% Rr, i.e. 90 to 170 degrees of Celsius) in the Middle to Upper Triassic stratigraphic interval. The Late Cretaceous lowering of the Kupferschiefer strata did not cause a significant increase in the maturity of organic matter. Heat transfer, connected with inflow of hydrothermal fluids causing of changes within the organic matter, was also responsible for ore mineralization of Kupferschiefer strata in about Middle to Late Triassic in the southern part of the Fore-Sudetic Monocline.