Shelf-facies microbiotas from the Odjick and Rocknest formations (Epworth Group; 1.89 Ga), northwestern Canada

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Abstract
Moderately well preserved microfossils are reported from two formations of the Epworth Group in the Wopmay Orogen. An assemblage in a stromatolitic unit in the uppermost part of the Odjick Formation contains the microfossils Huroniospora spp., Gunflintia sp., and Frutexites sp. This assemblage, which is remarkable for its preservation in a carbonate matrix, is similar to one found in a stromatolitic chert facies in the Gunflint Iron Formation of Ontario. Taxa in four membranes of the overlying Rocknest Formation are preserved in cherty dolomites of inner-shelf shallowing-upward cycles capped by small digitate stromatolites. These assemblages comprise the spheroidal taxa Huroniospora spp., Melasmatosphaera magna, Sphaerophycus sp., and Palaeoanacystis sp., the filamentous taxa Archaeotrichion sp., Eomycetopsis sp., Siphonophycus sp., Brevitrichoides sp., Biocatenoides incrustata, Gunflintia? sp., and Archaeonema sp., the acritarch Eomicrhystridium sp., and rare specimens of two unidentified and problematic taxa.