An annotated map of the Permian and Mesozoic formations of East Greenland

Abstract

A map has been compiled on the scale of 1:1 million showing Permian and Mesozoic rocks of East Greenland from 70° to 77° north latitude. The accompanying text briefly summarizes the existing knowledge of these rocks. Lower Permian (not shown on the map) is represented by non-marine formations which lie conformably on Upper Carboniferous. Upper Permian lies unconformably on Lower Permian and earlier rocks with a basal conglomerate. The remaining Upper Permian rocks include marine strata with a rich fauna. The lowest Triassic beds are marine with an abundant fauna which enables six ammonoid zones to be recognized. The rest of the Trias is almost entirely nonmarine, a mainly clastic redbed sequence with some evaporites. The Trias closes with deltaic beds with an abundant flora, which span the interval from Rhaetian to earliest Jurassic (Hettangian). The Jurassic succession is incomplete. The Middle Jurassic has yielded important ammonite faunas which make it a zonal standard for the boreal Jurassic, very different from that of Europe. Upper Jurassic rocks, mainly Upper Oxfordian and Lower Kimmeridgian, are widespread. Still higher Jurassic rocks are preserved in Milne Land. Lowest Cretaceous (Berriasian and Valanginian) rocks have yielded important faunas, which in the Valanginian include both North European and Mediterranean elements. The remainder of the Cretaceous succession is incomplete, and includes a number of horizons from Lower Aptian to Upper Campanian.

The palaeogeography of the present North Atlantic region from the Permian onwards is summarized. During Permian times an arm of the Arctic Ocean extended between Greenland and Norway to join up with the Zechstein Sea. This connection was broken in the early Trias, when the Muschelkalk Sea of Europe became connected with Tethys rather than with the Arctic Ocean. During the Lower Jurassic the Arctic connection was resumed. During the Lower Cretaceous there is, for the first time, evidence for the existence of the North Atlantic Ocean as far south as about 40° north latitude.