PT conditions of Pan-African granulite facies metamorphism in Sabaloka inlier, north of Khartoum, Sudan

The Sabaloka inlier, located 80 km north of Khartoum, comprises gneisses and migmatites with lenses, bands and irregular bodies of granulites. These are intruded by batholitic granitoids of Syn- to Late-tectonic emplacement. Sabaloka records the only occurrence of rocks of granulite facies in north and northeastern Sudan. These were correlated on lithological similarities and metamorphic history with the Archean granulites of northern Uganda. This chapter defines the pressure-temperature (PT) conditions of these granulites on the basis of microprobe analysis of co-existing mineral pairs of semi pelitic and enderbitic gneisses. Rocks of the granulite facies occur as remnant dark patches or discrete bands and lenses of variable dimensions ranging in size from few centimeters to hundred of meters across within biotite gneiss and migmatites. The granulites are made up of an association of metaigneous and metasedimentary gneisses. The metasedimentary granulite contains cordierite, garnet, biotite, plagioclase, K feldspar, quartz and sillimanite or hypersthene.