Structural Analysis and Investigations of Shear （剪的结构分析和调查）.pdfVIP

GS-11 STRUCTURAL ANALYSIS AND INVESTIGATIONS OF SHEAR-HOSTED GOLD MINERALIZATION IN THE SOUTHERN LYNN LAKE GREENSTONE BELT (PARTS OF NTS 64C/11, /12, /15, /16) by C.J. Beaumont-Smith, S.D. Anderson and Ch.O. Böhm1 Beaumont-Smith, C.J., Anderson, S.D. and Böhm, Ch.O. 2001: Structural analysis and investigations of shear-hosted gold mineralization in the southern Lynn Lake greenstone belt (parts of NTS 64C/11, /12, /15, /16); in Report of Activities 2001, Manitoba Industry, Trade and Mines, Manitoba Geological Survey, p. 67-75. SUMMARY Continuing structural analysis of the southern Lynn Lake greenstone belt has delineated six generations of ductile to brittle-ductile fabrics. Overprinting relationships among the various gener- ations of fabric suggest that the deformations represent discrete deformation having different kinematic frames. The oldest deformation (D ) is responsible for the tectonic assembly of Wasekwan Group metavolcanic rocks prior to the intrusion of 1 abundant plutons and the deposition of Sickle Group fluvial-alluvial arenaceous rocks. An intense D2 transposition-shearing deformation overprints the D1 geometry, producing the east-west distribution of the greenstone belt. Transposition associated with D2 is characterized by the development of shallowly plunging, upright, F2 isoclinal folds. The geometry of F2 folds suggests a shallow pre-D2 surface, a geometry most easily explained by D1 thrust imbrication of the Wasekwan Group. Late-stage D2 deformation is characterized by the development of regional-scale, D2 dextral-transpressional shear zones. This is reflected in the development of D2 shear zones within the greenstone belt, in addition to the previously identified Johnson Shear Zone developed along the southern margin of the belt. The o