Palaeoenvironment, palaeohydrography and chemostratigraphic zonation of the Canol Formation, Richardson Mountains, north Yukon

Sedimentological and geochemical results from samples in the Richardson Mountains indicate that siliceous shales and chert of the Canol Formation were deposited in stratified, oxygen-depleted waters that favoured the preservation of organic matter. Dilution by terrigenous input was minimal; however, fluctuating palaeoproductivity resulted in significant biogenic silica enrichment that reduced porosity. The Canol Formation was divided into four regionally correlatable chemostratigraphic zones. Each zone was characterized by up-section profiles of: decreasing biogenic silica enrichment, increasing proportions of siliceous shale relative to chert, decreasing redox-sensitive Mo, U and V enrichment factors and decreasing Mo/TOC (total organic carbon) ratios. A preliminary sequence stratigraphic framework was constructed and eustasy invoked as the dominant allogenic control. Mo/TOC ratios are indicative of a silled, restricted basin with euxinic deepwater. The overall decrease up-section of these ratios suggests increasing restriction over time, associated with relative sea-level fall. Comparison of north Yukon data with similar modern and ancient basins has constrained preliminary reconstructions of Canol basin palaeohydrography.

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Publisher Yukon Geological Survey


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License Open Government Licence - Yukon
Date published 2015-01-23
Date updated 2015-01-23


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