Progress report on geochronological investigations in the crystalline complexes of the East Greenland Caledonian fold belt between 72° and 74°N

Abstract

In the summer of 1974 two of the authors (D. C. R. & A. R. G.) collected samples from vanous crystalline units in the innerfjord region ofthe Caledonian fold belt between 72° and 74°N. with a view to testing current hypotheses of the geological history of the region. The only dates so far available from this region are a few K-Ar mineral ages reported by Haller & Kulp (1962) all of which reflect Caledonian orogenesis. In the Scoresby Sund region isotopic work on crystalline units comparable to some of those reported on here has yielded Archaean and middle Proterozoic as well as Caledonian ages (Hansen et al., 1973, 1974; Rex& Gledhill, 1974; Friderichsen & Higgins, this report).