Geochemestry of basic magmatism on Byers Peninsula, Antarctica

In this field campaign 59 samples of volcanic and subvolcanic rocks were collected. Ten of these samples were analyzed via ICP at the Department of Geology, U. de Chile. The samples are subalkaline rocks ranging in composition between basalt and rhyolite, with a predominance of basaltic to "basaltic-andesitic" magnetism with transitional affinities between tholeitic and calcalkine. The rocks show a high degree of fractionation and high rates of partial fusion, indicating origin in an island arc tectonic setting. The magnetism of the arc probably occurred during the early Cretaceous to the early Tertiary.