Orogene und kratogene Metallogenese

The typical features of metallogenic provinces in the orogenic belts are described and explained in the sense of the modern plate tectonics. Some phenomena, however, are not in agreement with the scheme of “consuming margins” — particulary the timing of the magmatic-tectonic cycles and the assembly of ore metals in mountain chains. Therefore the older assumption of a synorogenic anatexis of the continental crust has to be maintained. The metals of the continental crust got combined with the volatiles and with the metals of the basaltic magma to form ore deposits. The Alpine-Mediterranean metallogenesis seems to be the result of repeated and interfering subduction (producing deposits of Cu, Fe, Cr) and palingenesis (producing deposits of Pb-Zn, Au, Ag etc.) in Cretaceous and in Tertiary time. In the cratonic areas, three types of metallogenic provinces can be distinguished: Huge lakkolithes of liquid basic mantle magma with Cr, Ni, Cu, Pt — areas of granitization with a haphazard distribution of different ores — and the simple stratiform deposits in the stable platform cover; the latter as well as the small deposits along rifts and separating margins can best be explained as mobilisates created by heat flow and some mantle volatiles.