Crustal architecture of the south-east Superior Craton

The Neoarchean Abitibi sub-province of the south-east Superior Craton represents one of the most mineralized pieces of crust on Earth. Rich in both orogenic gold and base metal (Cu, Zn, Pb) VMS deposits, but relatively poorly endowed in komatiite-hosted Ni-Cu-PGE systems, the region appears to have a different mineral systems story to its Neoarchean counterpart; the Yilgarn Craton in Western Australia. Large-scale isotopic mapping using Sm-Nd and Lu-Hf systems have proven useful in understanding the large-scale cratonic architecture that controls metal endowment in the Yilgarn, and hence a major component of the Metal Earth project is to produce similar mapping products for the Superior Craton. Initial results from a small Lu-Hf dataset demonstrate a clear spatial variation in EHf across the Ontario Abitibi region. The area as a whole is juvenile, but small variations within these data correspond to east-west trending zones of relatively more- or less-juvenile crust. The occurrence of VMS systems and orogenic gold deposits correlate with the most juvenile zones, while the edge of these zones correlate with major structures important for mineralization, such as the Porcupine-Destor Fault. These observations suggest that crustal architecture has a fundamental large-scale control on regional metal endowment in the Abitibi sub-province.