The Kupferschiefer; an overview with an appraisal of the different types of mineralization

This marine bed is regarded as the type example of a shale-hosted, strata-bound sulfide deposit. The lithology and stratigraphy are described. Although large areas of the Kupferschiefer contain only average concentrations of base and precious metals compared to other shales and marls, in certain areas the concentrations reach ore grade. The Kupferschiefer in Poland, in two contrasting regions in Germany (the Lower Rhine basin and the Hessian depression) and in England (where it is termed the Marl Slate) are compared and provide evidence for four types of mineralization. These are studied and discussed. The Kupferschiefer is a deposit that appears to be the product of a variety of mineralizing processes influenced by the environment of deposition of the host rock and the underlying geology, but there are many unifying features, notably, that the bulk of the evidence still points to fixation of metals as sulfides by bacteriogenic processes. -after Authors