Comments on the genesis and structure of the copper-polymetallic ore deposit of the Foresudetic Monocline, SW Poland

Abstract

Summary The copper-polymetallic ore deposit is situated within the Foresudetic Monocline near its boundary with the Foresudetic Block. The copper-mineralized zone extends through a series of dolomites, dolomite/clay shales and white sandstones of the lowermost Zechstein and, possibly, the uppermost part of the Rotliegendes. Mineral compositions, the manner of their occurrence and the diverse internal structure of this stratified deposit all indicate a multistage origin. Synsedimentary mineralization took place in a reducing environment present both during deposition of the shales and dolomites and during sedimentation of the white sandstones. Black concretions containing large amounts of organic carbon, FeS 2 and FeO occur in the upper part of these sandstones. Mineralization also took place throughout diagenesis, mainly in the sandstones but also in the shales and, to a lesser degree, the dolomites. Sedimentation was on an unstable shelf within the neritic zone. It is considered that natural marine aqueous solutions were enriched in metal ions (mainly Cu, Pb, Zn) by hot brines flowing out into the sedimentary basin through deep fissures, such as those in the Middle Odra fault zone, situated near the deposit.