Resumé
Two kinds of structural domains are distinguished in this mobile belt: 'Nagssugtoqidian' shear belts, which wrap around large areas in which 'pre-Nagssugtoqidian' fold structures are preserved. Field and Pb-isotope data are presented which suggest: 1) that some of the gneisses are Archaean, as previously thought, but there are also some gneisses derived from Proterozoic intrusive rocks; 2) most of the supracrustal rocks in the area are probably of Proterozoic age; 3) the main phase of metamorphism took place at 1880 + or - 50 m.y.; and 4) most of the structures developed during a Proterozoic orogeny that can be broadly correlated with the Hudsonian orogeny in the Canadian Shield. Pb-isotope data and Pb/Pb isochron parameters are presented for supracrustal rocks in the Nagssugtoqidian and Rinkian mobile belts of W Greenland, and similar data for the granites and gneisses of W Greenland. -P.Br.
Originalsprog | Engelsk |
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Sider (fra-til) | 1126-1131 |
Antal sider | 6 |
Tidsskrift | Canadian Journal of Earth Sciences |
Vol/bind | 21 |
Udgave nummer | 10 |
DOI | |
Status | Udgivet - okt. 1984 |
Programområde
- Programområde 4: Mineralske råstoffer