Carbon Isotope Chemostratigraphy of Frasnian Sequences in
We present a! 13C profile for the Frasnian succession of the eastern part of the Western Canada Sedimentary Basin as a tool for proposing and justifying regional stratigraphic correlations. Eight positive! 13C excursions are identified that permit detailed correlations of Frasnian sequences for thes...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.547.3290 http://sil.usask.ca/holmden/list_2/holmden_et_al_2007_summary_.pdf |
| Summary: | We present a! 13C profile for the Frasnian succession of the eastern part of the Western Canada Sedimentary Basin as a tool for proposing and justifying regional stratigraphic correlations. Eight positive! 13C excursions are identified that permit detailed correlations of Frasnian sequences for these eastern areas. In particular, this composite! 13C profile may be used to compare ‘restricted ’ and sparsely fossiliferous, or non-fossiliferous Frasnian deposits of Saskatchewan with more open-marine deposits of eastern Alberta and the southwestern Great Slave Lake region. Chemostratigraphic correlations were found to agree with those previously inferred on the basis of ostracode biostratigraphy. This includes the postulation that, in Saskatchewan, a major regional unconformity caused the omission of Cooking Lake–Leduc oil-bearing strata, which explains the absence of a major positive! 13C excursion that is prominent in northeastern Alberta. The most probable explanation is that the Leduc reefs and associated carbonate platform in Alberta formed during a time of decreasing sea level, resulting in no sediment deposition and/or possible subaerial exposure and erosion of Leduc-equivalent strata in the shallower water environment of Saskatchewan. |
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