Granites of Petermann Ranges, East Antarctica and Implications on their Genesis

The hypersolvus granitic rocks of the Petermann Ranges in East Antarctica reveal high alkali content, generation from a relatively dry magma as shown by the field and petrological characters and development in an anorogenic selling as indicatcd by an indirect genetic linkage with the spatially associated Gruber anorthosite massif. Hence, their resemblance to A-type granites and generation in a tensional tectonic environment is suggested.

The petrochemical characters indicate that the partial melting of a heterogenous but largely metasedimentary source generated the melt for crystallisation of the Petermann granite. The heat required for melting was possibly released by the fractionating basic magma which produced the juxtaposed Gruber anorthosite massif.