Open AccessRegional geology of early Precambrian high-grade metamorphic rocks in West Greenland. Part 1: Kângnaitsoq to Ameralik
Author(s) -
B. F. Windley
Publication year - 1972
Publication title -
rapport
Language(s) - English
Resource type - Journals
eISSN - 2597-2944
pISSN - 0418-6559
DOI - 10.34194/rapggu.v46.7304
Subject(s) - geology , geochemistry , gneiss , granulite , precambrian , ultramafic rock , metamorphic rock , pegmatite , metamorphic facies , hornblende , sillimanite , schist , biotite , metamorphism , petrology , geomorphology , facies , paleontology , quartz , structural basin
Within this region three types of area are distinguished: 1. Amphibolite-grade areas which did not reach a granulite grade. 2. Granulite-grade areas. 3. Amphibolite-grade areas, many of which have been retrogressed from the earlier granulite grade. The main rocks are hypersthene-biotite gneisses, biotite-hornblende gneisses, amphibolites with or without orthopyroxene, sillimanite mica schists, rare marbles, skarns and quartzites, layered calcic anorthosites, a great variety of meta-ultramafic rocks including rare zoned talc lenses, abundant pegmatites, several generations of dolerite dykes locally amphibolitised by deep-seated fauIts. The fold structure of the region is characterised by abundant large-scale interference patterns. The history of the region is interpreted on the basis of a deformed cover/basement relationship, all major units being now mutually conformable.