ABSTRACT
The movement of fluids in MVT-mineralized provinces continues to be a major controversy. Much of this controversy results from an inability to differentiate between regional fluid migration ‘drives’ and focusing structures that localize the ore deposits. Numerical modeling of the fluid migrations suffers because of this aspect. New evidence for fault-controlled fluid flow in the southeast Missouri and in the Transvaal Basin MVT districts emphasizes the role which faults play in focusing fluids within a particular MVT mineralized province. In the Transvaal Basin of South Africa (Pering district), N-S fault-related breccia bodies follow 3 regional lineaments and MVT prospects form a locus within steep-walled breccia bodies. In southeast Missouri, sphalerite-galena-barite deposits are found continuously along strike of the St. Genevieve fault; these deposits are found higher in the stratigraphic section to the northeast of the major districts. In both districts, faults acted as channels of discharge (focused flow) for regional fluid migration within the basins
