- Accueil
- Publications spéciales = special publications
- Gisements stratiformes et provinces cuprifères - C...
- A synopsis of Canadian stratiform copper deposits in sedimentary sequences
Visualisation(s): 980 (30 ULiège)
Téléchargement(s): 1152 (7 ULiège)
A synopsis of Canadian stratiform copper deposits in sedimentary sequences
Abstract
Stratiform copper deposits in sedimentary sequences have not made significant contributions to Canadian copper production. Nevertheless, sufficient occurrences are known of this very important geological type of deposit to suggest that some potential exists. Occurrences are widely distributed in rocks of many ages but the main ones are found in Carboniferous rocks of the Canadian Appalachians and Proterozoic rocks of the Canadian Shield and Cordillera.
Analogous to similar deposits in other parts of the world, Canadian occurrences characteristically are found in sediments deposited in continental or marginal marine, low latitude, arid or semi-arid areas. A number of the occurrences, such as those in Mississippian rocks of the Canadian Appalachians, and Proterozoic rocks of the Seal Lake area Labrador, Coppermine River and Redstone River areas, Northwest Territories, and in the Gateway Formation of the Clark Range of Alberta and British Columbia, have formed in the basal rocks of a marine transgression following a long period of continental sedimentation.
All deposits and occurrences are found in rocks that postdate oxygenation of the earth's atmosphere (about 2 300 m.yr.). Because no bonafide example of this type of deposit has been found in the extensive, well explored Archean terranes of Canada, a relatively highly evolved atmosphere seems to have been essential for their formation.
The detailed nature, distribution and significance in Canada of this important geological type of deposit will not be known until further exploration and studies have been carried out.