Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Geology

Supervisor

Dr. Stephen R. Hicock

Abstract

This study reconstructs the ice flow history of the eastern portion of the Keewatin sector of the Laurentide Ice Sheet by integrating field work, remote imagery, and work by others. The study reveals at least seven ice flow phases during the Wisconsinan, including ice streams. A model was developed using inverse distance weighed (IDW) interpolation with GIS to identify and isolate potential kimberlite bedrock sources in kimberlite indicator mineral-rich areas in the Pelly Bay area, Nunavut. Kimberlite indicator mineral (KIM) data were normalized by “peer size” to better understand how KIM grains from three kimberlite sources are distributed within three size fractions of till. The IDW method successfully delineated previously unrecognized KIM dispersal trains that were hidden within the KIM-rich areas. The study also revealed that garnets reached their terminal grade at relatively short distances (2500-7500 m) down ice from their kimberlite sources. Mg-ilmenite is the dominant KIM in the area and Mg-ilmenite-rich samples tend to contain Cr-pyrope and orange garnets, with lesser Cr-diopside and chromite. Mg-olivine in these samples ranges from abundant to none. Mg-olivine-rich KIM in till is associated with the Umingmak kimberlites.


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