Publication Type:Journal Article
Source:Economic GeologyEconomic Geology, Society of Economic Geologists, Inc, Volume 103, Number 6, p.1309-1340 (2008)
Keywords:deformation, deposits, Gold compounds, Gold deposits, Lakes, mineralogy, Ores, Sulfur compounds, volcanic rocks, Volcanoes
The Kirkland Lake-Larder Lake gold belt includes the giant Kirkland Lake and world-class Kerr-Addison-Chesterville gold deposits, along with several smaller deposits and occurrences. It corresponds to an east-trending band of Timiskaming clastic and volcanic rocks that unconformably overlie older volcanic assemblages in the southern Abitibi greenstone belt of the Archean Superior province. The gold belt is bounded to the south by the Larder Lake-Cadillac deformation zone, which roughly follows the contact between the younger Timiskamine rocks and the older volcanic units. Three generations of fabrics formed during post-Timiskaming regional deformation (D2, D3, and D4) of the belt. North-south shortening during D2produced a penetrative, generally east-striking, steeply dipping, S2foliation, and an east-plunging, L2stretching lineation. S2is most intense within the syn-D2Larder Lake-Cadillac deformation zone and its northeast-trending splay, the Upper Canada deformation zone. The D2structures are overprinted by a north-trending crenulation cleavage S3, which formed during east-west D3shortening across the belt. A northeast-trending regional S4foliation associated with Z-shaped F4folds and overprinting both S2and S3formed during northwest-southeast D4shortening. Gold mineralization is localized along the Larder Lake-Cadillac deformation zone (Anoki and McBean deposits), the Upper Canada deformation zone (Upper Canada deposit), and the brittle Kirkland Lake fault and '04 Break (Kirkland Lake deposit), The Upper Canada, McBean, and Anoki deposits formed during D2, and, along with Kerr-Addison- Chesterville, Omega, and Cheminis deposits, are probably related to a regionally extensive hydrothermal system associated with the Larder Lake-Cadillac deformation zone, The sulfide-poor gold- and telluride-bearing quartz veins of the Kirkland Lake deposit are interpreted to have been emplaced during D4, synchronous with reverse-dextral movement along the ore-controlling brittle Kirkland Lake fault. The Kirkland Lake mineralization has a distinct metal signature (TeAu, Mo, Pb, Ag, high Au/Ag, low As) and probably represents a separate hydrothermal system linked to a deep magmatic (alkalic) fluid source and unrelated to mineralization along the syn-Dg deformation zones. 2008 Society of Economic Geoloeists, Inc.
Compilation and indexing terms, Copyright 2018 Elsevier Inc.<br/>20090911922570<br/>Deformation zone<br/>Gold mineralization<br/>Hydrothermal system<br/>Regional deformations<br/>Stretching lineations<br/>Structural setting<br/>Three generations<br/>Volcanic assemblages