Mg-Al skarn of the Skallevikhalsen on the east coast of Lutzow-Holm Bay, East Antarctica

The genesis of skarns that accompany crystalline marbles in the Skallevikhalsen region on the east coast of Lutzow-Holm Bay, East Antarctica, is discussed on the basis of the mode of occurrence and mineral paragenesis. The marbles in question are usually accompanied by distinctly zoned nodules that are thought to have been formed during the granulite facies metamorphism by the interaction of dolomitic limestones and exotic rock fragments incorporated in them. Examination in the CaO-MgO-(Al)_2O_3-SiO_2 system leads to the conclusion that the mineral parageneses observed in these skarns have been largely controlled by the chemical potentials of Mg, Al and Si. In addition, the significance of the occurrence of some semi-precious minerals, such as sapphire and spinel, is also briefly discussed in relation to similar minerals from Sri Lanka and southern India and the reconstruction of Gondwanaland