Geocheminar fall-2020

Mid-ocean ridge peridotites provide a rare but fruitful glimpse into the Earth’s interior, recording significantly greater chemical variability than do their erupted basalt counterparts. This variability may derive from modern processes related to melting and melt-rock interaction or from long-lived source heterogeneity related to recycled material or ancient melting events. In this talk, I’ll discuss variations in the geochemistry and thermodynamics of a suite of peridotites from a densely-sampled segment of the Southwest Indian Ridge. These variations can be tied primarily to modern melting and melt-rock reaction processes. However, neither of these processes appears to generate the observed variability in recorded oxygen fugacity, which may indicate that oxygen fugacity variations record evidence of long-lived source heterogeneity in the mantle.