The Blosseville coast basalts of East Greenland. Their occurrence, composition and temporal variations.

Major and trace element compositions are presented for basalts from the area between Kangerdlugssuaq and Scoresby Sund, East Greenland. In this area basalts are estimated to cover at least 54,000 km² at the present day. The bulk of these lavas have a very uniform composition and are tholeiites similar to those found on many oceanic islands with high FeO (total) and TiO2. The only significant variation is minor and represents a change to a more evolved type to the south, a variation which may be similar to that observed in Postglacial Icelandic lavas. The earliest lavas are of a picritic type with high modal olivine (up to 35%) and correspondingly high Ni and Cr contents. This province is therefore similar to the West Greenland succession. Typical continental or ocean ridge type basalts have not been found and nor has any sample corresponding to the postulated composition of the Skaergaard intrusion. A model for the development of volcanism in the area is suggested.