Geology and mineralogy of the pan-African Sedex massive sulfide deposits of Abu Samar, southern red sea hills, Sudan

Abstract EN

-The Abu Samar massive sulfide-Ba-Mn deposit, and adjacent occurrences, are hosted by a Proterozoic partially granitized and migmatitized para-gneissic assemblage in the southern part of the Red Sea Hills of the Sudan.

They are exposed as massive barite and manganese horizons, with minor gossans.

They contain an exotic inequilibrated and complex mineral paragensis of oxides, hydroxides and sulfide minerals as a result of three successive metamorphic events and at least four events of deformation.

The first metamorphic event (PI) is a regional upper amphibolite- granulite facies and anatexis that is contemporaneous with isoclinal folding Dl.

This was overprinted by a contact metamorphic event (P2) due to the emplacement of syn-collisonal, subduction-related granodiorite plutons that generated the second phase of deformation D2 that refolded Dl.

P2 raised the temperature and the whole system was then reset during an epizonal retrograde metamorphism (P3), accompanied by D3 that generated S3 foliation schistosity.

This was then followed by a later phase of a mild deformation D4 as well as a pervasive supergene alteration.

This led to the remobilization and increased the ore crystallinity along tectonically controlled pathways.