THE ORIGIN OF ARCHEAN GNEISSES IN THE FYFE HILLS REGION, ENDERBY LAND - FIELD OCCURRENCE, PETROGRAPHY AND GEOCHEMISTRY

Abstract

Granulite and amphibolite facies gneisses at Fyfe Hills in Enderby Land, East Antarctica, form part of an early Archaean (c. 3.8 Ga) terrain termed the Napier Complex. The gneissic sequence at Fyfe Hills is composed of both supracrustal and intrusive rocks. The oldest lithological association, the Layered Gneissic Series, is defined by interlayered felsic and basic metavolcanics and metasediments derived from psammitic, pelitic, ferruginous and calcareous precursors. Felsic gneisses in the Layered Gneissic Series have low Y/Ce, low Ga/Al and are low in incompatible elements and, therefore, correspond to Sheraton and Black's depleted granulites. The Layered Gneissic Series has been intruded b..