The geotectonic evolution of a portion of the Garies terrane, Kliprand, South Africa

Abstract

The Kliprand dome is a poorly investigated structure located in the central part of the high grade Garies Terrane of the western Namaqua Sector (NS) of the Namaqua-Natal Metamorphic Province (NNMP). This structure is host to a diverse variety of supracrustal rocks comprising predominantly metapelites and quartzites of the Kamiesberg Group, the streaky augen gneiss, an enigmatic pink gneiss (official name the Lekkerdrink Gneiss) of which the origin is obscure, the metasomatic charnockites along with the pre- to syn-tectonic two-pyroxene granulites (or gabbro-norite) of the Oorkraal Suite. Large bodies of garnet-quartz-feldspar granite, believed to be the products of dehydration melting during peak metamorphism, are referred to as the Ibequas Granite. The transformation of these sediments and volcanic rocks into gneisses and migmatitites was accomplished by intense regional metamorphism during the 1.2-1.0 Ga Namaqua Orogeny. In order to unravel the tectonic evolution of the Kliprand dome, a structural, lithogeochemical, isotopic and geochronological study was undertaken.