Geochemistry of the stratiform zinc-lead-barite mineralization at the Meggen mine, Federal Republic of Germany.

摘要

The Meggen orebody (Federal Republic of Germany) is a stratiform Zn-Pb-Ba deposit hosted by middle-upper Devonian pelagic limestone in a predominantly shale sequence.;Sulfide ore wedges out into barite; barite wedges into limestone. Ore consists of pyrite (72 wt.%), sphalerite (10%) and galena (1%) thinly interbedded with shale, and is overlain by a thin (0-0.5m) tuffitic shale.;Four distinct morphologies of pyrite are present in sulfide ore. The sequence of mineralization, pyrite;Metal content in stratigraphic sections is variable; Fe content is highest in the top of the ore section, (Zn + Pb) is highest in lower ore. Ore constituents are zoned laterally: ore thickness, sulfide and Fe contents are highest in the west of the mine, while the highest concentrations of Zn and Pb are some 0.5 to 1 kn east of the high-Fe zone. Mineralization is most intense in the west of the mine, and hydrothermal fluids probably discharged from this area.;Sulfur contents in unmineralized sediments are low, and ;Sphalerite and galena ;Ore formed by sulfide replacement of carbonate sediments. Hydrothermal fluids were discharged into the carbonate unit, which was sealed by the overlying tuffitic shale. Hydrothermal fluids were metal- and H