Stratigraphy, Sedimentology and Early Diagenesis of Pennsylvanian-Permian Mixed Carbonate-Siliciclastic Cyclothems, SW Ellesmere Island, Nunavut

• Main Author: Walker, Victoria M.
• Other Authors: Beauchamp, Benoit
• Format: Master Thesis
• Language: English
• Published: Graduate Studies 2013
• Subjects: Geology; Pennsylvanian; Permian; Mixed Carbonate-Siliciclastics; Cyclothems; Early Diagenesis; Subaerial Exposure; Meteoric Diagenesis; Microfacies; Canadian Arctic; Raanes Peninsula; Canyon Fiord Formation; Belcher Channel Formation; Nansen Formation; Arctic; Belcher; Belcher Channel; Ellesmere Island; Nunavut; Foraminifera*
• Online Access: http://hdl.handle.net/11023/930; https://doi.org/10.11575/PRISM/27888

Nine stratigraphic sections of Lower Moscovian (Pennsylvanian) to Sakmarian (Lower Permian) mixed carbonate-siliciclastic strata, belonging to the Canyon Fiord, Belcher Channel and Nansen formations were examined on SW Ellesmere Island, Nunavut. This succession is represented by fifteen microfacies indicative of environments ranging from open marine, reef, back-reef, shoal, lagoonal carbonates to nearshore sandstones. The studied succession is part of two long-term transgressive and regressive sequences bounded above and below by regional unconformities. These sequences are dated as Bashkirian-Kasimovian and Gzhelian-Sakmarian based on foraminiferal biostratigraphy. Superimposed on this trend are fifth-order sequences, or cyclothems, likely resulting from glacio-eustatic fluctuations. The recognition of distal and proximal cyclothems provided the basis to decipher the paleogeographic history of the area. The upper part of proximal cyclothems displays petrographic and isotopic evidence of subaerial exposure and meteoric diagenesis, which played a role in secondary porosity development, thus contributing to the economic potential of this succession.