Late Ordovician carbonate mounds from North Greenland: a peri-Laurentian dimension to the Boda Event?

Abstract

Late Katian (Late Ordovician) carbonate mudmounds in the Turesø Formation, Peary Land, North Greenland, succeed normal marine faunas dominated by brachiopods, bryozoans, cephalopod and gastropod molluscs, aulaceratid stromatoporoids, corals and receptaculitid algae, in the Børglum River Formation, and are themselves succeeded by organic-rich, largely barren limestones. This peri-Laurentian succession suggests deteriorating environmental conditions from a normal marine to a more restricted basin during the Late Katian and Hirnantian, against a background of gradual marine regression following the peak of the Boda Warming Event. The generally low-energy depositional setting probably lay within the Inter-Tropical Convergence Zone on the equator.

Keywords::

• carbonate mounds
• Katian
• Late Ordovician
• Peary Land
• Greenland

Acknowledgements

Our expedition to Peary Land was funded mainly by the Danish Council for Independent Research (FNU grant to David A.T. Harper), together with the Natural Sciences and Engineering Research Council of Canada (Jisuo Jin) and the University of Western Ontario (ADF grant to Jisuo Jin). The logistic support of POLOG and Station Nord together with the remarkable skill of our helicopter (Stacey) and Twin Otter pilots (Chris and Jim) made possible our penetration of the remote areas of North Greenland. Finally we thank Robin Cocks and an anonymous referee whose insightful review comments improved the manuscript.