Archean gold mineralization and metamorphism: timing constraints from precise U-Pb dating
Gold mineralization is tightly constrained to an event closely following establishment of peak metamorphic condition, in all areas of the Superior Province of Canada where precise dating has been applied to defined field relationships. In the Abitibi and Wabigoon Subprovinces of the Southern Superior Domain, peak metamorphism caused by major batholith emplacement is consistently >2685 Ma and affects Archean supracrustal units of all ages (mainly >2700 Ma). Gold is commonly hosted by felsic stocks, dated at a specific age in the Abitibi Belt (2688-2684 Ma), and is therefore close to or younger than peak metamorphism. Dateable units crosscutting mineralization are extremely rare, but at Shebandowan and Mine Centre dated field relationships bracket the maximum and minimum age of mineralization between 2689 - 2684 and 2692 - 2686 Ma, respectively. While the metamorphic event in the Northern Superior Domain is approximately 20 my older, relative timing of gold mineralization is identical. At Red Lake, gold is hosted by units ranging in age from 2990-2718 Ma, all metamorphosed at >2704 Ma. Peak metamorphic minerals are retrograded by alteration during gold localization and mineralization is cut by a 2704 Ma dyke. These data show that gold mineralization was the product of a tectonic event during the latest Archean which involved major plutonism, deformation and metamorphism.
- Research Organization:
- Ontario Geological Survey, Toronto (Canada)
- OSTI ID:
- 6651426
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GOLD ORES
GEOLOGIC HISTORY
ISOTOPE DATING
MINERALIZATION
ONTARIO
COPPER COMPOUNDS
LEAD ISOTOPES
METAMORPHISM
MINERALOGY
PLUTONIC ROCKS
TECTONICS
URANIUM ISOTOPES
VANADIUM COMPOUNDS
ACTINIDE ISOTOPES
AGE ESTIMATION
CANADA
IGNEOUS ROCKS
ISOTOPES
NORTH AMERICA
ORES
ROCKS
TRANSITION ELEMENT COMPOUNDS
580300* - Mineralogy
Petrology
& Rock Mechanics- (-1989)
580100 - Geology & Hydrology- (-1989)