Igneous rocks in the Proterozoic platform of eastern North Greenland

Abstract

The Proterozoic sandstones of the Inuiteq Sø Formation (Jepsen, 1971) and the Norsemandal Sandstone (Adams & Cowie, 1953) contain numerous sills, sheets and dykes of dolerites and other intrusive rocks. Locally, the intrusions may make up 75 per cent of the total section along some fjord walls. The sequence is overlain by basaltic vo1canics, locally up to 1300 m thick. The igneous rocks have been the main object of our field work and they are briefly described below. The intrusive rocks have been studied earlier by Koch (1925), Ellitsgaard-Rasmussen (1950) and Jepsen (1969); the occurrence of basaltic volcanics was reported and mapped by the Greenarctic Consortium in 1969 (personal communication to GGU).