The same and not the same: Ore geology, mineralogy and geochemistry of Rodinia assembly versus other supercontinents

Abstract It has been long observed that the amalgamation of supercontinents, including Rodinia, is coeval with peaks of U Pb ages of global detrital zircons. However, our new compilation of global geochemical, mineralogical, and ore geologic records shows that the assembly of Rodinia stands out from others, in terms of whole-rock trace element geochemistry, as well as records of mineralogy and ore deposits. During the assembly of Rodinia, Nb, Y, and Zr concentrations were enriched in igneous rocks, with prolific formation of zircon and minerals bearing Th, Nb or Y, and formation of NYF-type pegmatites and REE ore deposits. At the same time, many types of ore deposits are relatively poorly represented in Rodinin terranes, including deposits of orogenic gold, porphyry copper, and volcanic hosted massive sulfide deposits, with a corresponding paucity of many minerals (e.g., minerals bearing Au, Sb, Ni) associated with these deposits. We interpret these records as indicating the prevalence of ‘non-arc’ magmatism and a relative lack of subduction-related arc magma preserved in the surviving pieces of the Rodinia supercontinent, distinct from other episodes of supercontinent assembly. We further attribute the prevalence of ‘non-arc’ magmatism to enhanced asthenosphere–lithosphere interactions in the Mesoproterozoic, and speculate that the lack of ‘arc-collisional’ magma may be related to enhanced erosion of Rodinia orogenic belts.