Ngoye

The Ngoye Granite-Gneiss Formation is located in the extreme northeastern part of the Natal portion of the Namaqua-Natal Mobile Belt and is an elongate body extending over 30 km. It consists of a broad spectrum of granite and granodioritic gneisses amongst which is peralkaline granite gneiss that extends along the southern margin for about two thirds of its length. The granites comprise abundant quartz, approximately equal amounts of microcline and albite (An0-12), biotite, riebeckite and occasional aegirine, these three minerals forming aggregates; fluorite as a common accessory. Riebeckite granite forms bands up to 50 m wide within the riebeckite-biotite granite and contains ubiquitous zircon which may reach a centimetre in length in pegmatitic portions. Analyses of major and some trace elements for four peralkaline granites are given by Scogings (1986).