Geology and structure of the Larsemann Hills area, Prydz Bay, East Antarctica

Abstract

The Larsemann Hills area in Prydz Bay, East Antarctica, underwent low pressure granulite facies metamorphism about 1100 Ma ago. This peak metamorphic age is similar to that of large areas west of the Larsemann Hills, but contrasts with the Archaean age of the Vestfold Hills only 100 km to the northeast. The dominant rock types in the Larsemann Hills are metapelitic cordierite‐ and Fe‐Ti oxide‐rich gneisses and various leucogneisses. Felsic, garnet‐bearing, variably foliated ‘yellow gneiss’ (60% of outcrop) and the extremely cordierite‐rich ‘blue gneiss’ (10% of outcrop) constitute the two major metasedimentary units. Mafic dykes, charnockites and evidence of brittle deformation are absent, and there are minor orthogneisses as well as mafic two pyroxene gneisses that lack garnet and ultramafic rocks. These features distinguish the Larsemann Hills not only from the Archaean Vestfold Hills to the northeast, but also from the 1000 Ma old ‘transition zone’ in the Rauer Group and outcrops of similar age to the ...