Does the silicate Earth have a leaky bottom? - Research seminar with Prof Tim Elliott

Geodynamic models have long modelled plumes originating from the bottom of the mantle. From this perspective, hot-spot magmatism provides a sample of the deepest mantle and potentially might carry evidence of on-going chemical exchange from core to mantle. Implicating protracted core-mantle interaction from the geochemistry of hot-spot magmas has been a sporadically popular notion over the last fifty years. In the last decade, unradiogenic values of 182W/184W have been reported in some hot-spot lavas, which provides perhaps the most convincing evidence of leakage from core to mantle. In this talk, I will assess this idea against alternative theories to account for unradiogenic 182W/184W in oceanic basalts and explore its implications for the longer term evolution of the mantle.