An overview of gold systems in Uganda

Detailed analyses of historic and recent information on active and abandoned gold mines and alluvial workings in combination with new regional geochronology, documentation and interpretation of the lithostratigraphy, structural setting, hydrothermal alteration and mineralisation, and geochemistry of mineralised rocks have formed the basis for the definition of four major gold districts in Uganda: (1) the Busia gold district hosted in the Neoarchean Busia-Kakamega granite-greenstone belt in the SE of Uganda, which contains the structurally controlled mesozonal Tira gold mine; (2) the Mubende gold district in the Paleoproterozoic Rwenzori fold belt in central Uganda, which hosts the structurally controlled metasediment-hosted mesozonal Kamalenge and Kisita gold mines; (3) the Buhweju-Mashonga gold district in SW Uganda, which contains the vein hosted Pb-Zn-Au Kitaka mine, the structurally controlled intrusion-hosted mesozonal Mashonga gold mine and the structurally controlled sandstone-hosted mesozonal Muti and Kanywambogo mines; and (4) the Karamoja gold district, which is hosted in reworked Archean basement rocks and/or in the upper amphibolite-lower granulite facies rocks of the Neoproterozoic Mozambique fold belt in NE and W Uganda and in the northern part of the Karamoja gold district containing numerous hypozonal shear zone-controlled gold workings. Other areas in Uganda where alluvial gold mineralisation and/or shallow gold workings are reported comprise the Kitgum area within the Aswa shear zone in northern Uganda, the Western Nile area, which represents the western extremity of the Bomu-Kibalian shield of NE Congo, and the Kabale-Kisoro area hosted in the Mesoproterozoic North Kibaran fold belt in SW Uganda. The results of this work are an early attempt to portray the gold metallogeny of Uganda. Future studies, including geological mapping at all scales, geochronology, whole-rock geochemistry and chemical and mineralogical studies of mineralised samples, will help clarify the distribution and origin of diverse gold systems in this poorly understood part of Africa. © 2014 Geological Society of Australia.