Anomalous supply of bioessential molybdenum in mid-Proterozoic surface environments

•We review widespread global occurrences of molybdenite in mid-Proterozoic granites.•Mesoproterozoic sandstone provenance is dominated by mid-Proterozoic, and possibly Archean, sources.•We conclude molybdenum availability to the Mesoproterozoic surface was high.•Molybdenum needed for spread of multicellular life at this time was readily available.

Granites aged 1.9 Ga to 1.5 Ga exhibit molybdenite mineralization globally. Sandstones deposited during the mid-Proterozoic have a provenance dominated by 1.9–1.7 Ga basement. The mid-Proterozoic surface environment was, consequently, receiving detritus from the molybdenum-rich granites. Thus there was a supply of molybdenum available in terrestrial or shallow marine environments at a time when molybdenum was required to support the evolution of multicellular life.