•Witwatersrand, South Africa, Elliot Lake, Canada, Sierra do Jacobina, Brazil, Tarkwa, Ghana and the Guyana Shield area in Colombia
•Earth’s atmosphere was a different one from today’s oxidizing conditions Archaean to the Early Proterozoic (3,100-2,200 Ma), some also extending into the Middle Proterozoic such as the Tarkwa (1,900 Ma)
•oligomictic mature conglomerates intercalated with sequences of less mature conglomerates and sandstones
•sedimentary to hydrothermal mobilization
•Archaean granite-greenstones
•Braided streams in alluvial fans (Au)
•Carbonaceous layers (algal mats) = low-energy regime deposit with U and fine Au