A pertographic and geochemical study of selected peridotitic and pyroxenitic xenoliths from the three kimberlite localities in the Lac de Gras region, Northwest Territories, Canada

Includes bibliographical references. Eighty-five peridotitic and pyroxenitic xenoliths from the Arnie, Pigeon and Misery kimberlites in the Lac de Gras region, Northwest Territories, Canada were selected for inclusion in this study. The three kimberlites are situated within a 40 km radius of one ano...

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Bibliographic Details
Main Author: Doyle, Patricia Mary
Other Authors: Le Roex, Anton, Gurney, John
Format: Master Thesis
Language:English
Published: University of Cape Town 2002
Subjects:
Online Access:http://hdl.handle.net/11427/17210
https://open.uct.ac.za/bitstream/11427/17210/1/thesis_sci_2002_doyle_patricia_mary.pdf
Description
Summary:Includes bibliographical references. Eighty-five peridotitic and pyroxenitic xenoliths from the Arnie, Pigeon and Misery kimberlites in the Lac de Gras region, Northwest Territories, Canada were selected for inclusion in this study. The three kimberlites are situated within a 40 km radius of one another on the BHP property, and all are diamond-bearing. The Misery kimberlite is presently being mined, and the Pigeon kimberlite is part of ยท the future BHP-DiaMdt Ekati mining plan. A petrographic study of the xenoliths using both transmitted light microscopy and binocular microscopy was followed by major anti trace element analysis. Major element compositions of individual minerals were determined using a wavelength dispersive electron microprobe, and trace element abundances were determined using laser ablation ICP-MS. Pressures and temperatures of equilibration were then determined using 'garnet-olivine, garnet-orthopyroxene and trace element geothermobarometers (TNi, Per).