Alkaline Rocks and Carbonatites of the World

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

Jebel Teis

stripes

Occurrence number: 
155-00-082
Country: 
Sudan
Location: 
Longitude: 29.77, Latitude: 10.67
Carbonatite: 
No

The eastern half of this complex includes a partial ring-dyke of peralkaline quartz syenite containing sodic amphibole and aegirine. Within the ring-dyke is an area of volcanic rocks that are interpreted as remnants of the roof of the syenite unit. The volcanics are generally felsic types including ignimbrite and trachyte. The western half of the complex consists of three units younging westwards. The first and third are peralkaline quartz syenites, the second a peralkaline granite. Within the granite in one area are lenses and small dykes giving high scintillometer readings. These are composed of quartz, alkali feldspar, iron oxides, fluorite and zircon and in one sample finely disseminated bastnasite.

Economic: 
Relatively high values for a range of trace elements, including REE, were found in these rocks.
References: 

CURTIS, P. and BRINKMANN, K. 1985. The geology of younger intrusive alkali complexes in the southwestern Nuba Mountains, Sudan. Geologisches Jahrbuch, 63: 3-41.

Map: 
Fig. 3_291 Alkaline intrusions of the southwest Nuba Mountains (after Curtis and Brinkmann, 1985, Geological Reconnaissance map, 1:250,000).
Location: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith