Alkaline Rocks and Carbonatites of the World

Setup during HiTech AlkCarb: an online database of alkaline rock and carbonatite occurrences

Bayuda

stripes

Occurrence number: 
155-00-053
Country: 
Sudan
Region: 
Bayuda Desert intrusions
Location: 
Longitude: 32.1, Latitude: 17.5
Carbonatite: 
No

Situated in the extreme southwestern corner of the Bayuda Desert this 12x8 km complex is intruded into basement gneisses but partly obscured by superfical deposits. A 3-4 km wide central syenite, cut by trachytic dykes in the northwest, is surrounded by successive rings of amphibole and biotite granite with quartz porphyry dykes. On the eastern side of the complex lies a heavily faulted area of microgranite, quartz porphyry dykes and altered basement which is overlain by rhyolitic lavas in the northeast. A further area of syenite lies on the eastern margin of the complex. There are several late basaltic intrusions.

Age: 
A Rb-Sr determination on peralkaline granite gave 365±7 Ma (Barth et al., 1983).
References: 

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 (unpublished) BARTH, H., BESANG, C., LENZ, H. and MEINHOLD, K.-D. 1983.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.

Map: 
Fig. 3_281 The Gilif Hills (No. 155-00-050) with the volcanic rocks of Wadi Abu Rugheiwa to the west of them. Also shown are Jebel Nashki (No. 155-00-035), Jebel Umm Handal (No. 155-00-036), Bayuda (No. 155-00-053) and Abu Dom (No. 155-00-041). (after 1:250,000 geological map, Barth and Meinhold, 1981).
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