Early Cambrian microfossils from the Portfjeld Formation, Peary Land, eastern North Greenland

Abstract

The Portfjeld Formation of eastern North Greenland is a dominantly carbonate sequence which, in its type area around Jørgen Brønlund Fjord, Peary Land, lies between the mainly clastic intervals of the Morænesø Formation, below, and the Buen Formation of early Cambrian age, above (Jepsen, 1971). In J. C. Christensen Land and Valdemar Glückstadt Land, to the east and south-east, the formation lies variously on sandstones of the Campanuladal Formation or dolomites of the Fyns Sø Formation (O'Connor, 1979). The age ofthe Portfjeld Formation has not previously been known with any degree of certainty, although its general occurrence between supposed tillites of the Morænesø Formation (Troelsen, 1956; Jepsen, 1971; Clemmensen, 1979) correlated with the Varanger sequence of Norway and the fossiliferous early Cambrian Buen Formation has caused most workers to suggest a late Precambrian - early Cambrian age. The term Eocambrian has often been applied.