Late Archean Prograde Amphibolite- to Granulite-Facies Relations in the Fiskenæsset Region, Southern West Greenland
| Autor: | V. R. McGregor, C. R. L. Friend |
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| Rok vydání: | 1992 |
| Předmět: | |
| Zdroj: | The Journal of Geology. 100:207-219 |
| ISSN: | 1537-5269 0022-1376 |
| DOI: | 10.1086/629583 |
| Popis: | The Tasiusarsuaq terrane in the Fiskenaesset-Nuuk region of southern West Greenland is interpreted as a late Archean tilted crustal section modified by deformation. The northern part of the terrane was affected by granulite-facies metamorphism at about 2810 Ma, but large areas were subsequently retrogressed to amphibolite facies. In the prograde amphibolite- to granulite-facies transition in inner Bjornesund a relatively sharp, but highly irregular front that crosses structures and lithological boundaries on outcrop scale separates orthopyroxene-free from orthopyroxene-bearing rocks. Outcrop relations resemble in some ways examples of "arrested charnockite formation" described from high-grade regions in southern India and Sri Lanka. Relations in the transition zone in Bjornesund appear to be the result of late, local influx of a fluid, presumably rich in $$CO_{2}$$, that permitted orthopyroxene to grow at the expense of hornblende. Regional considerations suggest a genetic connection between granulite-faci... |
| Databáze: | OpenAIRE |
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