Granulite Facies Metamorphosed Basic Dykes of the Torngat Mountains, Labrador

William C. Morgan and Frederick C. Taylor
Geological Survey of Canada, Ottawa, Ontario, Canada

Summary: In the Four Peaks region of Labrador Precambrian hornblende granulite facies metamorphosed basic dykes discordantly cross the foliation of garnet-hornblende-pyroxene granulites with sillimanite-garnet-biotite-quartz-feldspar gneiss. Most of the dykes are schistose or banded, but some are massive and undeformed with blastophitic textures. Mineral analyses are given for the equilibrium assemblage in one analysed clinopyroxene-orthopyroxene-amphibole-garnet-plagioclase- quartz blastophitic dyke. Dyke intrusion occurred after formation of the host rock foliation, while the metamorphism was about 1400 Myr ago.

Mineralogical Magazine; June 1972 v. 38; no. 298; p. 666-669; DOI: 10.1180/minmag.1972.038.298.02
© 1972, The Mineralogical Society
Mineralogical Society (