Publication Type:
Journal ArticleSource:
Exploration and Mining Geology, Pergamon Press [for the] Geological Society of the Canadian Institute of Mining, Metallurgy and Petroleum, New York - Oxford, International, Volume 4, Number 4, p.381-393 (1995)ISBN:
0964-1823Keywords:
Archean, Canada, dikes, eastern canada, faults, gold ores, Greenstone Belts, Hydrothermal alteration, intrusions, massive deposits, massive sulfide deposits, metal ores, metamorphic belts, metasomatism, mineral assemblages, mineral deposits, genesis, Mineral exploration, mineralization, Noranda Quebec, Precambrian, quebec, sulfides, veins, VOLCANISMAbstract:
This fault set defines the E margin of the Despina cauldron, nested within the Noranda cauldron. The faults are stratabound, displacing the stratigraphy of the cauldron fill but not offsetting the cauldron cover, and are occupied by dykes that acted as eruptive centres to volcanic members of the cauldron-filling sequence. Displacement across the fault set is >> 750 m, and coincides with post-cauldron volcanism. Feeder dykes cross-cut each other and are typically depleted in Na (sub 2) O and CaO, and enriched in MgO, K (sub 2) O, Fe (sub 2) O (sub 3) and MnO relative to fresh flows. Economic and subeconomic massive sulphide deposits occur near the fault set at different levels over a stratigraphic thickness of 3000 m. Numerous Cu occurrences and much hydrothermal alteration occur in and next to the fault set. The faults define a fault set which controlled the location of magmatism, hydrothermal alteration and mineral deposition during the early evolution of the Noranda cauldron. Significant sulphide mineral deposition commonly occurred near the intersection of the McDougall-Despina fault set with NE-trending synvolcanic faults. Recognition of synvolcanic faults is therefore a major objective of exploration programmes for volcanic-associated massive sulphide deposits.
Notes:
GeoRef, Copyright 2018, American Geological Institute.<br/>1996-045309<br/>McDougall-Despina Fault
