Volcanism and Volcanic Rocks in Antarctica

Abstract

The distribution of volcanoes in Antarctica, especially those of the later part of Cenozoic time, has considerable bearing on any interpretations of orogenic patterns or history. The volcanic rocks vary considerably in composition throughout the Marie Byrd Land and Victoria Land, forming a large alkalic province. The South Shetland Islands, lying of the Antarctic Peninsula, are composed of olivine basalt and andesite, all of which are rich in soda, but their mineralogy is similar to that of high-alkali tholeiite with high-alumina content and its derivatives. Strontium isotopes and some minor elements of the Ross Island volcanics which occur on the margin of the continent are very similar to those of oceanic island as a hot spot. In this paper the origin and differentiation of the volcanic rocks from West Antarctica are discussed on the basis of chemical composition and strontium isotopes.