Plume-related mafic volcanism and the deposition of banded iron formation

We have compiled a record of the geochronology of mantle plume activity bet ween 3.8 and 1.6 Ga. Over this time period, the ages of komatiites, and tho se of global plumes, correlate strongly, at the 99% confidence level, with the ages of banded iron formations (BIFs). The ages of continental plumes c orrelate more weakly, at an overall 85% confidence level. Using the geochro nological records of these events, we can define four periods characterized by mantle superplume activity. Three of these periods are also times of en hanced BIF deposition. The fourth mantle plume period may similarly be coev al with increased BIF accumulation, but the BIF chronostratigraphic resolut ion is not accurate enough to test this rigorously. Mantle superplume volca nism may promote BIF deposition by increasing the Fe flux to the global oce ans through continental weathering and/or through submarine hydrothermal pr ocesses. It may also be enhanced by increasing the number of paleotectonic environments appropriate for BIF deposition (particularly plume-induced oce an plateaus, seamounts, and intracratonic rifts) and by promoting global an oxic, Fe-rich hydrothermal plumes in the shallow to intermediate marine wat er column.