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.