Abstract
The oldest rocks recognized in the Greenland Archean are metamorphosed basic, ultrabasic, and sedimentary rocks enclosed in the ca. 3700 m.y. old Amîtsoq gneisses of the Godthåb region, West Greenland. Specimens from enclaves from the area south and southeast of the town of Godthåb have been analyzed for major elements and for a range of minor and trace elements (U, Th, Pb, Hf, REE, Ba, Cs, Zr, Nb, Y, Sr, Rb, Cr, Ni, Co, Cu). These rocks, for which the term Akilia association is introduced, include basic and ultrabasic rocks, some with komatiitic and others with Fe-rich tholeiitic affinities; banded ironstones; and gneisses of detrital sedimentary origin. The range of lithologies suggests that the rocks of the Akilia association are fragments of a greenstone-belt type of sequence that was intruded and disrupted by the granitic parents of the Amîtsoq gneisses.
