Mineralizacja kruszcowa w okolicach Czernej k. Krzeszowic

Abstract

ORE MINERALIZATION IN THE VICINITY OF CZERNA, NEAR KRZESZOWICESummaryThe area under consideration lies in the south-eastern part of the Silesian-Cracow ore basin. In the vicinity of Czerna two structural stages may be distinguished, the older stage consisting of Lower Carboniferous limestones that dip southwards under an angle of about 40–60°. Along the Czernka river valley they rest in a contact with shale-sandstone formations of Namurian age. These formations are overlain with almost flat-lying deposits, Buntsadnstein, Lower Muschelkalk and Jurassic in age, which make here the upper structural stage. The Lower Muschelkalk formations are represented by the Gogolin Beds (ore-bearing limestones or dolomites) and the Lower Olkusz Beds (ore-bearing dolomites).A deposit of limestone and marcasite, described by Cz. Kuźniar (1930), occurs at the contact of the ore-bearing dolomites and Carbonic limestones. At present, mineralization has been ascertained to occur also in the Carbonic limestones, the Roethain dolomites, at the bottom and within the ore-bearing dolomites, and in the Jurassic conglomerates. Here are found: galena, cerussite, pyrite, and marcasite, as well as oxidized areas, limonite and galmei. Such a composition and a high content of zinc and lead in the limestones prove their relation to the Triassic deposits of Zn-Pb ores in the Silesian – Cracow area. The hard limonites are probably of post-sulphide origin, their soft varieties being formed due to weathering of dolomites.Thus, the genesis of the mineralization at Czerna seems to be closely related to that of the Silesian – Cracow zinc-lead deposits.