The geochemistry and sm-nd isotopic systematics of precambrianmafic dykes and sills in the southern prince charles mountains, East Antarctica

Abstract

Mafic dykes are a characteristic geological feature of the Ruker Complex in the southern Prince Charles Mountains. We present new geological, geochemical, and Sm-Nd isotopic data for these rocks, which place constraints on their genesis, mantle sources, and relative timing, as well as providing a substantial basis for a comparison between these intrusions and similar rocks from other Archaean terranes of East Antarctica.The oldest of the intrusions form dykes composed of distinctive rocks rich in Mg, Cr, and Ni. These rocks were probably derived via varying degrees of partial melting of a metasomatically enriched and radiogenic mantle source at relatively shallow mantle levels. Younger and v..