UBC Theses and Dissertations
Structural geology of Empire mine, Empire Development Company Limited, Port McNeill, B.C. Lund, John C.
Empire mine is located on north-central Vancouver Island about two miles south of Benson Lake; Orebodies are typical of the many contact metasomatic iron deposits of the West Coast of British Columbia. They occur in Bonanza volcanic rocks and Quatsino limestone of Upper Triassic age near the margins of a small granitic stock of intermediate composition. Structural controls at Empire mine are in part the configuration of the intrusion contact and in part the intersection of steep northeasterly faults with (a) folded and fractured volcanic rocks at the Merry Widow deposit and (b) with swarms of northwesterly striking greenstone dykes in the Kingfisher deposits. The Kingfisher fault transects both the Merry Widow and Kingfisher orebodies as well as the West Pipe and is considered one of the main channels for mineralizing solutions. Relatively intense folding occurs near margins of the Coast Copper stock. In the Merry Widow area, plot of poles to bedding on Schmidt equal area net indicate a north-northwesterly plunging major fold. Superimposed on this are minor drag and disharmonic folds. Fold axes all strike northerly sub-parallel to the intrusion contact and folding is considered a direct response to emplacement of the Coast Copper stock. Relation between intrusive greenstone and local folding would suggest that final stages of Bonanza volcanism, regional folding and emplacement of the stock with local folding and mineralization may be nearly contemporaneous.
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