Reconnaissance field mapping of Paleozoic rocks along the Churchill River and Churchill coastal area, northeastern Manitoba (parts of NTS 54E, L, K)

Manitoba Geological Survey Summary The 2014 field component for phase 2 of the Geological Survey of Canada’s Geo-mapping for Energy and Minerals program in Manitoba consisted of visits to key outcrop locations along the Churchill River and in the Churchill coastal area. Lithostratigraphic type sections for the Upper Ordovician Portage Chute, Surprise Creek, Caution Creek, Chasm Creek and Red Head Rapids formations are all located along the Churchill River and its tributaries. All the type section localities were visited by the authors, with the exception of the type locality for the Caution Creek Formation (for this formation, exposures at other sites were visited). The exposures visited around Churchill provide a comparative section, demonstrating the stratigraphic complexities caused by proximity to the Proterozoic Churchill quartzite, which stood out as islands during the Ordovician. The Lower Paleozoic strata visited along the Churchill River correlate well with observations the authors have made in core from boreholes, and in field visits to other parts of the Hudson Bay Basin. Although there are broad similarities to strata of similar age in other parts of the basin, some of the sections visited in the Churchill coastal area exhibit features that are distinctly local in distribution and reflective of the diverse microenvironments characteristic of nearshore conditions.