Precambrian Rb-Sr isochron ages from the crystalline complexes of inner Forsblads Fjord, East Greenland fold belt

Abstract

Several collections of samples were made from crystalline units in inner Forsblads Fjord by D.C.R. and A.R.G. in 1974. Result of whole rock Rb-Sr analyes on two of these collections are presented here, and give an Archaean age for banded gneises and amiddle Proterozoic age for quartzitic metasediments. These ages confirm the occurrence of major Precambrian complexes within the East Greenland Caledonian fold belt (Hansen el al., 1973a, b, 1974; Rex & Gledhill, 1974; Rex el al., 1976; Henrik en & Higgins, 1976: Higgins 1976). Analyses were carried out using standard technique (Van Breemen & Dodson, 1972).