T233 Metamorphism into the 21st Century II—A Celebration of the Career of Mike Brown

Wednesday, 13 October 2021
1:30 PM - 5:30 PM
Portland Ballroom 252 (Hybrid Room)

CORUNDUM GENESIS IN ALUMINOUS LEUCOSOME AT THE BLUE JAY SAPPHIRE OCCURRENCE (BRITISH COLUMBIA, CANADA) AS A RECORD OF METAMORPHISM AND PARTIAL MELTING IN THE MONASHEE COMPLEX

Paper number: T233-6
Program: Technical Sessions
Time: 2:40 PM – 2:55 PM

Authors

  • Lindsey Abdale Presenting Author
    Department of Earth, Ocean and Atmospheric Sciences, Vancouver, BC

Abstract

The aluminous leucosome-hosted sapphire (corundum) occurrence near Revelstoke, British Columbia, Canada, occurs in the Monashee Complex of the Omineca Belt of the Canadian Cordillera. Corundum occurs in banded or pod-like shapes within a leucosome containing muscovite + biotite + albite + orthoclase + garnet ± zircon ± sillimanite ± ilmenite ± monazite ± rutile ± spinel ± titanite. Whole rock geochemistry and petrological observations show that the leucosomes attained crystal-melt equilibrium between melts with high SiO2, K2O, and CaO compositions and peritectic plagioclase, corundum, and garnet, with additional silica melt later removed from the system. Petrography and thermodynamic modeling of the corundum-bearing pods show that corundum formed from muscovite dehydration melting at the peak of metamorphism at 800-850 °C and 8-10 kbar. Zircon geochronology in the U/Pb system shows that partial melting occurred during the final stages of prograde metamorphism and that melting was continuous from ~60–50 Ma.

Geological Society of America Abstracts with Programs. Vol. 53, No. 6

doi: 10.1130/abs/2021AM-364762

© Copyright 2021 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.