The possible roles of Precambrian biota in the origin of magmatogene and hydrothermal silver-bearing vein deposits

• Published in: Canadian Journal of Earth Sciences
• Main Authors: Morton, Roger D., Changkakoti, Amarendra
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1987
• Subjects: General Earth and Planetary Sciences; Great Bear Lake
• Online Access: http://dx.doi.org/10.1139/e87-030; http://www.nrcresearchpress.com/doi/pdf/10.1139/e87-030

The origins of silver-bearing, polyelement vein associations in the Great Bear Lake region and elsewhere in the world might be traced back to possible organic-rich, Precambrian sedimentary protoliths. These protoliths could have yielded a characteristic spectrum of elements to hydrothermal systems during regional metamorphism or during anatexis to form S-type granitoids. Wholesale capture of metals and metalloids by microbiota and their remains may have been a characteristic of some Early Proterozoic marginal marine, mesosaline environments. Two possible atmosphere–hydrosphere–lithosphere models are considered in light of recent theories. The metallogenic effects of Early Proterozoic organic-rich sedimentary environments could be of great significance: they might account for the polyelemental signatures of many younger, remobilized metal liferous systems.