stripes
The northern part of the Muweilih ring-complex cuts the Ban Gidid complex (No. 155-00-037) and in the east is itself truncated by the Sultaniyat volcanic complex (No. 155-00-039). It comprises three parts: Muweilih in the north, which is predominantly intrusive, and Meigil and Musran in the south and east, which are predominantly volcanic, the whole complex being some 15 km in diameter. The Muweilih ring consists of arfvedsonite-riebeckite and aegirine granites which cut earlier biotite granites with marginal rings and cone sheets of quartz porphyry and spherulitic rhyolite; six major granite units have been mapped. The Musran Group of volcanic rocks is probably the older and comprises hawaiite, benmorite and alkali feldspar trachytes. The younger Meigil group is more acid being predominantly of rhyolitic lavas and pyroclastic rocks including ignimbrites. Both units were preserved in cauldrons the ring faults now being occupied by dykes of hedenbergite-biotite granite.
ALMOND, D.C., CURTIS, P.A.S., MCCORMAC, M., O'HALLORAN, D.A. and VAIL, J.R. 1984b. Migrating younger granite ring-complexes in the Bayuda Desert, northern Sudan. Bulletin, Faculty of Earth Sciences, King Abdulaziz University, Jeddah, 6: 271-6.BARTH, H. and MEINHOLD, K.-D. 1979. Mineral prospecting in the Bayuda Desert. Part 1, Volume A. Investigation of mineral potential. Technical Report Sudanese-German Exploration Project. Hannover (Bundesanstalt fur Geowissenschaften und Rohstoffe). 336 pp. (unpublished) BARTH, H., BESANG, C., LENZ, H. and MEINHOLD, K.-D. 1983. Results of petrological investigations and Rb/Sr age determinations on the non-orogenic igneous ring-complexes in the Bayuda Desert, Sudan. Geologisches Jahrbuch, 51: 1-34.
