|Title||Project Unit 13-002. Stratigraphy, geochemistry and petrogenesis of the Black Thor mafic to ultramafic intrusive complex and associated chromium and nickel-copper-platinum group element mineralization,
McFaulds Lake greenstone belt, Ontario|
|Author||Carson, H J E; Lesher, C M; Houlé, M G; Weston, R J; Shinkle, D A|
|Source||Summary of field work and other activities, 2013; by Ontario Geological Survey; Ontario Geological Survey, Open File Report 6290, 2013 p. 52.1-52.15 Open Access|
|Links||OGS OFR 6290 Online - En ligne (pdf, 204
|Alt Series||Earth Sciences Sector, Contribution Series 20130222|
|Publisher||Ontario Geological Survey|
|Media||paper; on-line; digital|
|Lat/Long WENS|| -86.5000 -86.0000 53.2500 52.7500|
|Subjects||metallic minerals; igneous and metamorphic petrology; stratigraphy; geochemistry; petrogenesis; mineralization; chromium; nickel; copper; cores; geochemical analyses; lithology; chromite; ultramafic
rocks; mafic rocks; gabbros; pyroxenites; peridotites; dunites; metamorphic facies; greenschist facies; textural analyses; field relations; petrographic analyses; McFaulds Lake greenstone belt; Black Thor intrusive complex; platinum group elements;
|Program||Targeted Geoscience Initiative (TGI-4) Mafic-Ultramafic Ore Systems|
|Abstract||The Black Thor intrusive complex (BTIC) contains one of the largest and best-preserved chromite deposits in the world, and is one of an increasing number of deposits recognized to have formed in
magmatic conduits from high-chromium, low-magnesium komatiitic magmas. Similar deposits occur at Kemi, Finland (Alapeiti et al. 1989), Inyala, Zimbabwe (Rollinson 1997), Ipueira-Medrado, Brazil (Marques et al. 2003) and Sukinda, India (Mondal et al.
2006); however, little is known about the genesis of this class of chromite deposits, which is fundamentally different from traditional stratiform- and podiform-type deposits. |
Indicated and inferred resources of the BTIC exceed 102 million tonnes
(Mt) of chromite, with an aggregate thickness up to 100 m of bulk ore at grades of 31% Cr2O3 in a zone measuring up to 3 km in strike (Weston and Shinkle 2013). One of the main issues associated with this deposit and others of this type is explaining
the crystallization of such a large quantity of chromite within what appears to be a relatively small intrusive complex. There is much debate regarding the formation of these types of chromite deposits, and several theories have been suggested:
physical transportation of slurries of finely dispersed chromite (Mondal and Mathez 2007), with or without magmatic slumping (Maier, Barnes and Groves 2013) and/or in situ crystallization associated with oversaturation of chromite with oxidation
(Ulmer 1969), wall-rock contamination (Irvine 1975) and magma mixing (Campbell and Murck 1993).
The purpose of this article is to present the main objectives, research methods, preliminary results, preliminary implications, and the future work
for a PhD thesis study undertaken by H.J.E. Carson at Laurentian University. This ongoing project is being supported by Cliffs Natural Resources, the Natural Sciences and Engineering Research Council of Canada (NSERC) Collaborative Research and
Development Program, the Ontario Geological Survey (OGS), and the Targeted Geoscience Initiative 4 (TGI-4) of the Geological Survey of Canada (GSC), which is part of the Earth Sciences Sector of Natural Resources Canada.
|Summary||(Plain Language Summary, not published)|
The Targeted Geoscience Initiative (TGI-4) is a collaborative federal geoscience program that provides industry with the next generation of geoscience
knowledge and innovative techniques to better detect buried mineral deposits, thereby reducing some of the risks of exploration. The purpose of this contribution is to present the main objectives, research methods, preliminary results, preliminary
implications, and future work for this PhD study undertaken by H. Carson at Laurentian University. The topic of the study is the Stratigraphy, Geochemistry, and Petrogenesis of the Black Thor Intrusive Complex and Associated Cr and Ni-Cu-PGE
Mineralization, McFaulds Lake Greenstone Belt, Ontario.