Tectonic development of base-metal and barite-vein deposits associated with the early Mesozoic basins of eastern North America

Abstract

Epithermal base-metal and barite-vein deposits are structurally, temporally, and almost certainly genetically associated with rift basins. Approximately 100 vein occurrences of this type occur near early Mesozoic basins of the eastern United States. The veins appear to form as a result of transport of moderate temperature brines from within the basins and adjacent basement rocks to shallow sites of mineral precipitation. Mineral deposition appears due to cooling, sulfate reduction, wall-rock reaction, and possibly fluid mixing, with the relative importance of these processes varying in different deposits. A period of fluid migration appears to occur late in the history of basin development due to the dynamic and changing stress regime developed during the tectonic transition from continental rifting to sea-floor spreading. -from Author