Catriona Breasley

Catriona Breasley
PhD Student in Geological Science, University of British Columbia

Trace element geochemistry and quantitative analyses of spodumene and quartz intergrowth textural groups at the Tanco pegmatite, Manitoba.

The Lithium-Caesium-Tantalum (LCT) type Tanco pegmatite in Manitoba, presents an exceptional example of pegmatite evolution, fractionation, and zonation on all scales, from regional to micro. The Tanco pegmatite hosts zones of significant lithium mineralization and is the only current lithium-producing mine in Canada. At this locality, the bulk of lithium mineralization occurs as spodumene and quartz intergrowths (SQUI). This study presents textural evidence from thin section petrography and cathodoluminescence imaging (CL) to describe four major groups of spodumene at Tanco: (1) Classic SQUI, (2) Micro SQUI, (3) Equant SQUI, and (4) Primary SQUI. Subsequent geochemical and quantitative analyses using electron probe microanalysis (EPMA), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), electron backscatter diffraction (EBSD), X-ray computed tomography (micro-CT) and Rietveld powder X-ray diffraction (XRD) reveal insight into the nature and formation of the different spodumene groups at Tanco. Results from these complimentary techniques reveal a complex crystallization history with multiple mechanisms of SQUI formation.

Authors: Catriona Breasley, Tania Martins, Robert Linnen and Lee Groat


Catriona Breasley is a current Ph.D. fellowship student at the University of British Columbia under the supervision of Dr. Lee Groat, Dr. Tania Martins, and Dr. Robert Linnen. She completed her integrated master’s degree with first-class honors at the University of St Andrews in Scotland. Her Master’s thesis, supervised by Dr. Eva Stüeken and Dr. Michael Byrne, investigated deep-sea polymetallic deposit formation beneath the Arctic ice sheet using Python modeling of hydrothermal vent plumes. Her Ph.D. research in collaboration with Sinomine Resources Group Ltd and the Manitoba Geological Survey focuses on lithium mineralization within the Tanco pegmatite, Manitoba. She uses a variety of techniques to geochemically analyze, visualize, and quantify the proportions of spodumene and quartz in the lithium-enriched regions of the pegmatite. She is the current Co-President of the UBC Society of Economic Geologists’ student chapter and has received multiple departmental scholarships and international research grants to support her Ph.D. research.