stripes
The main section of Jebel Buram is a 7 km diameter, approximately circular intrusion of peralkaline quartz syenite with a small core of less alkaline syenite. The peralkaline rock consists of perthite, quartz, sodic amphibole and/or aegirine with accessories including fluorite and calcite. The southwestern area of the complex is mainly a microgranite containing phenocrysts of alkali feldspar and quartz within a matrix, which is sometimes granophyric, including sodic amphibole and a little biotite. There are numerous small remnant patches of volcanic rocks associated with the microgranite including felsic pyroclastic rocks and trachytic lavas. Four analyses of the main peralkaline quartz syenite are given by Curtis and Lenz (1985).
CURTIS, P. and BRINKMANN, K. 1985. The geology of younger intrusive alkali complexes in the southwestern Nuba Mountains, Sudan. Geologisches Jahrbuch, 63: 3-41.CURTIS, P. and LENZ, H. 1985. Geological and geochronological investigations of selected alkali igneous complexes in the Nuba Mountains, southern Kordofan, Sudan. Geologisches Jahrbuch, 69: 3-24.
