stripes
Occurrence number:
155-00-069
Country:
Sudan
Location:
Longitude: 29.07, Latitude: 11.68
Carbonatite:
No
This intrusive complex consists of three overlapping units with a small area of felsic pyroclastic rocks. The earliest intrusion is a subalkaline syenite which is cut by a peralkaline syenite of perthite, a little quartz, interstitial sodic amphibole and minor aegirine. This was followed by a peralkaline granite with sodic amphibole and accessory zircon and fluorite. Scattered outcrops of quartz-feldspar porphyry appear to define a ring-dyke of 10.5x7.5 km; this rock also contains sodic amphibole.
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_290 Alkaline intrusions of the northwesterly part of the southwest Nuba Mountains (after Curtis and Brinkmann, 1985, Geological Reconnaissance map, inset, 1:250,000).
Location: