Eclogite xenoliths from the Chidliak kimberlite, Baffin Island, Nunavut, Canada ...
I studied the petrography, major element chemistry, geothermobarometry, and trace element chemistry of 19 eclogite xenoliths from Chidliak kimberlites (Baffin Island, Nunavut, Canada). These granoblastic, partially melted, mostly bi-mineralic eclogites are composed of pyrope and omphacite, with acce...
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| Format: | Text |
| Language: | English |
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University of British Columbia
2017
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| Online Access: | https://dx.doi.org/10.14288/1.0357260 https://doi.library.ubc.ca/10.14288/1.0357260 |
| Summary: | I studied the petrography, major element chemistry, geothermobarometry, and trace element chemistry of 19 eclogite xenoliths from Chidliak kimberlites (Baffin Island, Nunavut, Canada). These granoblastic, partially melted, mostly bi-mineralic eclogites are composed of pyrope and omphacite, with accessory orthopyroxene, kyanite, and rutile, as well as secondary chlorite, serpentine, phlogopite, amphibole, and spinel. The Chidliak eclogites are classified in the Coleman’s groups A, B, and C based on the garnet composition, and into groups A and B based on the clinopyroxene composition. Parameters of the eclogite formation were calculated by projecting clinopyroxene-garnet temperatures onto a geotherm constrained using Chidliak peridotite xenoliths. Thermobarometry of Chidliak eclogites yields temperatures of 855-1390°C and pressures of 45 70 kbar, i.e. in the diamond stability field. The temperatures may have been overestimated by 50-120°C due to the inability to account for Fe³⁺ in clinopyroxene and garnet. ... |
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