Wenlockian graptolite reference section, Clearwater Creek, Nahanni National Park, Northwest Territories, Canada

A sequence of 20 m of Wenlockian graptolite-bearing strata is described from southern Northwest Territories. The sequence is relatively rich in graptolites and represents the best Wenlockian graptolite interval yet known in the Canadian Cordillera, even though the fauna is notably lacking in many of...

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Bibliographic Details
Published in:Canadian Journal of Earth Sciences
Main Author: Lenz, A. C.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1980
Subjects:
Online Access:http://dx.doi.org/10.1139/e80-106
http://www.nrcresearchpress.com/doi/pdf/10.1139/e80-106
Description
Summary:A sequence of 20 m of Wenlockian graptolite-bearing strata is described from southern Northwest Territories. The sequence is relatively rich in graptolites and represents the best Wenlockian graptolite interval yet known in the Canadian Cordillera, even though the fauna is notably lacking in many of the typical Wenlockian species. The following Wenlockian biostratigraphic units are recognized (from oldest to youngest): centrifugus Zone, "Beds with C. cf. perneri", rigidus Zone, "Beds with Monograptus firmus nahanniensis", testis-lundgreni Zone, and "Beds with Pristiograptus etheringtoni".Graptolites described in this study comprise Monograptus antennularius, M. firmus nahanniensis n. subsp., M. flemingii, Pristiograptus sardous, P. etheringtoni n. sp., Monoclimacis flumendosae, Cyrtograptus centrifugus, C. cf. hamatus, C. cf. perneri, and C. rigidus from Wenlockian strata, as well as the first report from outside China of the late Llandoverian genus Sinodiversograptus.