Open AccessTourmaline in Precambrian supracrustal rocks from Aasiaat, central West Greenland
Author(s) -
Peter Appel
Publication year - 1988
Publication title -
rapport
Language(s) - English
Resource type - Journals
eISSN - 2597-2944
pISSN - 0418-6559
DOI - 10.34194/rapggu.v140.8031
Subject(s) - tourmaline , precambrian , geology , geochemistry , outcrop , conglomerate , feldspar , quartz , paleontology , sedimentary rock
Close to the town Aasiaat/Egedesminde supracrustal rocks outcrop on some small islands situated around the position 68°46'N and 52°38'W. The largest of these islands, Isuamiut, is barely a few kilometres long and the islands are situated more than 10 km from the mainland. an Isuamiut two tourmaline-rich layers or tourmalinites have been found (Ellitsgaard-Rasmussen, 1954). Tourmalinite is a peculiar rock type consisting mainly of tourmaline together with quartz, feldspar or mica, sometimes with appreciable amounts of sulphides andlorscheelite. The chemical composition of the tourmaline in tourmalinites is to some extent indicative of the genesis of the boron. I therefore decided to collect some samples of tourmaline on Isuamiut when passing the area on a boat journey along the west coast of Greenland during July 1987.