Predictive mapping for orogenic gold prospectivity in Uganda / Прогнозное картирование перспективности на месторождения золота орогенного типа в Уганде

In the last 15 years the concept of mineral systems approach to understanding orogenic gold systems has been developed. The orogenic gold model, as defined by Groves et al. (1998) argues for gold to be deposited during compressional deformation in accretionary orogens, from hydrothermal fluids derived from the metamorphism of greenstones. These deposits are typically found in late Archaean or in Palaeoproterozoic greenstone belts (Groves et al., 2007) and include the world class gold provinces of Yilgarn Craton, Superior Province, the Birimian of West Africa and the Tanzania Craton. Archaean and Palaeoproterozoic gold-forming events correlate with the growth of juvenile continental crust and resulting ores have been protected for billions of years within large, stable cratons. 
Uganda overlies the African plate, formed by the accretion of smaller Archaean Cratons welded together by mobile belts (Begg et al., 2009) of Archaean – Proterozoic age. Much of the northern and central Uganda is underlain by Archaean basement gneisses, forming approximately two-thirds of the country. Archaean rocks of the Nyanzian-Kavirondian system are exposed in the south-east and form part of the extensive granite-greenstone terrane of the Tanzanian Craton. Three major Proterozoic belts underlie central and west Uganda: the Palaeoproterozoic Ubendian belt (2100-1860 Ma) comprises the Buganda Toro metasediments, the Mesoproterozoic Kibaran belt (1375 Ma) comprising the Karagwe Ankolean metasediments and Neoproterozoic Pan African rocks (~500 Ma). 
According to Trauth et al. (2008) gold mineral occurrences have been found at Busia in the south-east, hosted within the Nyanzian-Kavirondian Archaean greenstone belt, whilst in the south-west at Kiboga and Kigezi, gold in quartz veins is hosted in the Palaeoproterozoic metasediments of the Buganda Toro Supergroup. Karamoja, in the north-east, is of particular interest since favourable gold potential is known to exist in the intrusive and volcano-sedimentary rocks of Proterozoic and possibly Archaean age. The potential significance of north-west Uganda is poorly understood, however the Kibalian mobile belt known host to the Kilo-Moto gold mines of the Democratic Republic of Congo (DRC) is believed to extend into Uganda. <...>