Geology and structural evolution of the Tashota Deformation Zone and implications for orogenic gold mineralization

Abstract

The Tashota Deformation Zone (TDZ) is a north-striking, ductile structure within the Onaman- Tashota Belt in the eastern Wabigoon subprovince of the Archean Superior Province in northwestern Ontario. The < 2700 Ma TDZ has never been studied in detail, despite its location along the boundary between a large batholith and Mesoarchean and Neoarchean volcanic rocks, its north trend in a belt where most ductile structures trend east-west, and the presence of orogenic gold mineralization. The TDZ is a high strain zone that formed along the batholith- volcanic rock boundary during the development of a dome-and-keel architecture in the central Onaman-Tashota Belt. During this deformation event, gold was emplaced along the TDZ contemporaneously with significant gold deposit formation to the south in the Beardmore- Geraldton Belt during syn-accretionary imbrication of volcanic and sedimentary rocks along the southern margin of the Wabigoon subprovince.