CHARAKTERYSTYKA MINERALIZACJI KRUSZCOWEJ CECHSZTYNU NA OBSZARZE WEISSWASSER W NIEMCZECH

Abstract

THE CHARACTERISTICS OF ORE MINERALIZATION IN THE WEISSWASSER COPPER DISTRICT, GERMANY

Abstract. The research deals with drill core samples collected during exploration of copper in the Weisswasser area in Saxony. Thearea is the north-western part of the North-Sudetic Basin, the lithostratigraphic section of which is similar to the typical one known from the Lubin district. As a result of mineralogical observations using reflected light microscopy and scanning electron microscopy, the following
minerals were identified: chalcopyrite, chalcocite, bornite, digenite, galena, sphalerite, native silver, Ag amalgams, mckinstyite, anilite and betechtinite. Detailed characteristics of the occurrence of sulphide mineralization is presented, describing its form, mutual inclusions and paragenesis, relationship to microtectonic conditions, as well as implications of morphological changes on the bottom of the Zechstein.
Three forms of mineralization were found: (1) horizontal, mid-layered copper sulphide lenses formed by hydraulic peeling along the sludge lamination surfaces caused by mineralized high-pressure solutions, (2) horizontal copper sulphide lenses replacing previous framboidal pyrite lenses, and (3) replacement of bioclasts. Copper sulphides were concentrated at the expense of sulphur deposited during sedimentation
and early diagenesis as bacterial pyrite. Ore mineralization occurs in the thin horizon with an extensive microtectonic net. Two tectonic episodes can be distinguished: Mesozoic tectonic events that enabled seismic pumping of hot fluids, and microfractures that developed during ore minerals precipitation. Futhermore, single sharp-edged grains of chalcopyrite disturbing lamination of copper shale are observed.
It indicates the displacement of grains from crushed conglomerate and resedimentation together with copper shale.