Do Olivine Crystallization Temperatures Faithfully Record Mantle Temperature Variability?

Crystallization temperatures of primitive olivine crystals have been widely used as both a proxy for, or an intermediate step in calculating, mantle temperatures. The olivine-spinel aluminum-exchange thermometer has applied to samples from mid-ocean ridges and large igneous provinces, yielding considerable variability crystallization We supplement the existing data with new temperature estimates for Hawaii, between 1282 ± 21 1375 19°C. Magmatic may be linked if thermal changes during melting can quantified. magnitude this change depends on melt fraction, itself controlled by temperature, composition lithosphere thickness. Both thickness vary spatially temporally, systematic differences ridges, ocean islands provinces. For provide robust evidence variability, controls lithology must isolated. develop multi-lithology model predicting magmas intra-plate volcanic provinces ridges. find that high seen at plume localities do require In absence further constraints productivity, we cannot robustly infer variable ocean-islands alone; example, extremely obtained Tortugal Phanerozoic komatiite could derive comparable modern-day Hawaii. This work demonstrates limit petrological thermometers when other geodynamic parameters are poorly known.