Cornwallis Island (75°N, 94°W), in the Canadian high Arctic, preserves an extraordinary Ordovian-Silurian slope facies that was isolated from later Paleozoic deformation by the formation of the Boothia Uplift. Graptolitic calcareous mudstones, carbonates, shales, and dolostones were deposited in the slope extension (Cape Phillips Formation) of the carbonate-rich Shelf Province of the Early Cambrian to Early Devonian Franklinian succession.
A spectacular (3D) graptolite fauna exists within the Cape Phillips Formation. In addition, the Cape Phillips Formation preserves the otherwise rare co-occurrence of graptolite and conodont faunas in abundant lime mudstones and concretions. It is thus the best section known to attempt this research.
For this study (in progress), 181 conodont samples were collected from overlapping sections through the entire Lower Silurian. In an interdisciplinary team approach, chitinozoan, radiolarian, and carbon isotope samples were also collected. Taxonomic description of the condonts and correlation with the graptolite zonation will provide a greater resolution and test of hypothesized Silurian bio-events, sea-level changes, climate and ocean state models, and chemical events in the Silurian.
AAPG Search and Discovery Article #90925©1999 AAPG Foundation Grants-in-Aid