Publication Type:
Book ChapterSource:
Targeted Geoscience Initiative 4; contributions to the understanding of Precambrian lode gold deposits and implications for exploration, Geological Survey of Canada, Calgary, AB, Canada, p.49-54 (2015)Keywords:
Abitibi Belt, Archean, Canada, Canadian Shield, cleavage, dikes, eastern canada, faults, folds, gold ores, Hydrothermal alteration, intrusions, lithologic controls, metal ores, metasomatism, mineral deposits, genesis, North America, Ontario, Precambrian, quartz veins, shear zones, structural controls, superior province, tectonics, veinsAbstract:
The Larder Lake-Cadillac deformation zone (LLCDZ) is a major deformation zone within the southern Abitibi subprovince of the Archean Superior Province. It hosts several gold deposits, including the Cheminis and the giant Kerr Addison-Chesterville deposits in Ontario. The two deposits occur along a strongly deformed band of Fe-rich tholeiitic basalt and komatiite of the Larder Lake Group (ca. 2705 Ma), bounded on both sides by younger, less deformed, Timiskaming turbidite (2680-2670 Ma). Gold was emplaced during D (sub 2) closure of an extensional Timiskaming basin, following the formation of early F (sub 1) folds. D (sub 2) deformation was a progressive compressive deformation event that began with regional F (sub 2) folding and the formation of a regional S (sub 2) cleavage, and ended with the localization of the deformation along the band of older volcanic rocks, the formation of the LLCDZ, and the introduction of gold during south-side-up reverse-slip faulting along the LLCDZ. The presence of weakly deformed syenite dykes suggests a minor magmatic contribution to the gold-bearing hydrothermal fluids. Thus, gold was deposited as hydrothermal fluids flowed upward along the LLCDZ during D (sub 2) south-side-up shearing.
Notes:
GeoRef, Copyright 2018, American Geological Institute.<br/>2016-084453<br/>Cheminis Mine<br/>Larder Lake-Cadillac deformation zone
