Metamorphism and intrusion in the Benjamin Lake map-area, Northwest Territories ...
Benjamin Lake map-area lies within the Archaean Slave province of the Canadian Shields. It is underlain by metamorphosed volcanic and sedimentary rocks of the Yellowknife Group that are tightly folded and have been intruded by a series of granodiorite plutons. Assessment of the relations between met...
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| Format: | Text |
| Language: | English |
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University of British Columbia
2011
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| Online Access: | https://dx.doi.org/10.14288/1.0104843 https://doi.library.ubc.ca/10.14288/1.0104843 |
| Summary: | Benjamin Lake map-area lies within the Archaean Slave province of the Canadian Shields. It is underlain by metamorphosed volcanic and sedimentary rocks of the Yellowknife Group that are tightly folded and have been intruded by a series of granodiorite plutons. Assessment of the relations between metamorphism and intrusion is based mainly on field observations, on the results of a petrographic study of over 300 thin sections of the metasedimentary and granitic rocks, and on mineral compositions determined by optical methods. The reactions that produced the various metamorphic minerals are discussed. Regional metamorphic grade in the metasediments ranges from the upper part of the greenschist facies to the middle part of the cordierite-amphibolite facies of the low pressure andalusite-sillimanite facies series. Pelites and semipelites of amphibolite grade are knotted schists characterized by large porphyroblasts of cordierite and andalusite. Metamorphism, in part synkinematic, has outlasted regional ... |
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