Babingtonite in an early Archaean metabasalt from the Pilbara Block, Western Australia

Abstract

are present of complex composition which might be in part altered aenigmatite, but the low Ti of the silicate grains does not support this, even accepting the loss of Na during hydration. The original composition of these grains remains unknown and analyses 5 and 6 of Table I record typical compositions. Conclusions. Remarkably iron-rich amphibole and pyroxene corresponding to arfvedsonite and aegirine have been identified.