Student Field Trip 17 visited a number of paleoplacer and orogenic gold deposits throughout southwest Ghana over a week. The itinerary and route map include visits to active open-pit and underground operations, including Damang, Iduapriem, Nkran/Esaase, Obuasi, Prestea-Bogosu, and Wassa, as well as exploration projects at Homase-Akrokerri, all hosted within the Birimian Supergroup. The course material covers the geology and mineralization of these deposits in the context of regional and local geological settings, focusing on their similarities and differences, ore resources, deposit models, and exploration methods.

Student Field Trip 17 visited a number of paleoplacer and orogenic gold deposits throughout southwest Ghana over a week. The itinerary and route map include visits to active open-pit and underground operations, including Damang, Iduapriem, Nkran/Esaase, Obuasi, Prestea-Bogosu, and Wassa, as well as exploration projects at Homase-Akrokerri, all hosted within the Birimian Supergroup. The course material covers the geology and mineralization of these deposits in the context of regional and local geological settings, focusing on their similarities and differences, ore resources, deposit models, and exploration methods.

Abstract Paleoproterozoic terranes of the Man-Leo Shield in the southern part of the West African craton host one of the world’s largest gold provinces with an overall endowment >10,000 metric tons (t). Although gold deposition commenced by ca. 2170 Ma, most deposits formed later, either during the inversion and metamorphism of intraorogenic sedimentary basins between ca. 2110 and 2095 Ma, or during later transcurrent deformation and associated widespread high K plutonism following docking of Archean and Paleoproterozoic domains within the craton at ca. 2095 Ma. Deposits formed between ca. 2110 and 2095 Ma include those with free gold in quartz veins and refractory gold in arsenopyrite and/or pyrite, and are associated with halos of carbonate, sericite, chlorite, and albite alteration. Most are located in bends and intersections between shear zones, minor faults, folds, and entrained blocks of relatively reactive igneous rock. Conglomerate-hosted gold deposits of the Tarkwa district formed early in the 15-m.y.-long period. Gold deposits that formed subsequently between ca. 2095 and 2060 Ma have a wider variety of styles, geologic settings, and metal assemblages. District-scale albite, carbonate, and tourmaline alteration, hydrothermal breccias, and a close relationship to high K granitoids characterize some of these deposits, whereas others are more typical orogenic gold deposits that are similar to those formed earlier during the craton evolution.