Publication Type:

Journal Article

Authors:

Lafrance, Bruno; DeWolfe, Jerry C.; Stott, Greg M.

Source:

Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre, National Research Council of Canada, Ottawa, ON, Canada, Volume 41, Number 2, p.217-235 (2004)

ISBN:

0008-4077

Keywords:

Canada, Canadian Shield, chemically precipitated rocks, deformation, eastern canada, faults, folds, gold ores, host rocks, iron formations, lineation, Lithoprobe, metal ores, mineralization, North America, Ontario, orientation, Sedimentary rocks, shear zones, structural analysis, superior province, tectonics, Wabigoon Belt

Abstract:

The Beardmore-Geraldton Belt occurs along the southern margin of the Archean Wabigoon subprovince, Superior Province, Ontario. The belt consists of shear-bounded interleaved metasedimentary and metavolcanic units. The units were imbricated from 2696 to 2691 Ma during D1 thrusting and accretion of the Wabigoon, Quetico, and Wawa subprovinces. Post-accretion D2 deformation produced regional F2 folds that transposed lithological units parallel to the axial plane S2 cleavage of the folds. During D3 deformation, the folds were overprinted by a regional S3 cleavage oriented anticlockwise of F2 axial planes, and lithological contacts and S2 cleavage were reactivated as planes of shear within dextral regional shear zones that generally conform to the trend of the belt. D3 is a regional dextral transpression event that also affected the Quetico and Wawa subprovinces, south of the Beardmore-Geraldton Belt. Gold mineralization at the Leitch and MacLeod-Cockshutt mines, the two richest past-producing gold mines in the Beardmore-Geraldton Belt, is associated with D3 shear zones and folds, overprinting regional F2 folds. The plunge of the ore zones is parallel to F3 fold axes and to the intersection of D3 shear zones with F2 and F3 folds.

Notes:

GeoRef, Copyright 2018, American Geological Institute.<br/>2004-039206<br/>Beardmore-Geraldton Belt