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Detailed Reference Information |
Brown, M., Friend, C.R.L., McGregor, V.R. and Perkins, W.T. (1981). The late archaean qoˆrqut granite complex of southern West Greenland. Journal of Geophysical Research 86: doi: 10.1029/JB080i011p10617. issn: 0148-0227. |
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Granites and granite pegmatites composing the ~255-Ma Qoˆrqut granite complex occur in a SSW-NNE trending linear belt >150 km long extending through the Buksefjorden-Ameralik-Godth¿bsfjord region of southern West Greenland. The main body of the complex crops out over a distance of 50 km from Ameralik to Kapisigdlit kangerdlaut and reaches a maximum outcrop width of 18 km between Stor¿ and Qoˆrqut. Around Qoˆrqut the complex comprises three main groups of granites: early leucocratic granites, various grey biotite granites, and late aplogranite-granite pegmatites. Within the 1500-m vertical section available in this area the complex has a tripartite structure comprising a lower zone dominantly of polyphase granite with a complex sheeted structure, and an upper zone dominantly of country rock sheeted by granite. Fifty-two specimens of granite have been analyzed for major, minor, and some trace elements. Geochemical variation within the complex is consistent with earlier fractional crystallization or partial melting, but in both cases, feldspar+biotite must have been involved either as fractionating phases or as residual phases during melting to account for the trace element chemistry. Two possible models for the generation of the complex are either anatexis of granulite facies rocks in the lower crust following an influx of violates nd heat from the mantle or melting at intermediate depths of amphibolite facies rocks with volatiles supplied by breakdown of hydrous phases. |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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