Alkaline basaltic volcanism in the Tertiary of central East Greenland - the Trekantnunatakker

The Trekantnunatakker rise from the inland ice NW of the head of Kangerluss uaq fjord on the Blosseville Coast of central East Greenland. In these nuna taks the main sequence of Tertiary flood basalts is overlain by picritic an d ankaramitic lavas. These mildly alkaline lavas have lower Nd-143/Nd-144 a nd higher Sr-87/Sr-86 than the tholeiitic hood basalts. Their isotopic and incompatible element characteristics are similar to those of moderately enr iched ocean island basalts, and comparable to the alkaline lavas of the nea rby Prinsen af Wales Bjerge. The Trekantnunatakker lavas were the result of small-volume deep melting and it is concluded that an enriched GIB-type so urce was present as a component of the East Greenland plume.