New paper out in Geophysical Research Letters (available open access here) hypothesizes that geochemical and geophysical observations of the deep lower mantle are consistent with metallic melt trapped during the solidification of the mantle magma ocean. Metallic melt would host siderophile and incompatible elements detected in hotspot volcanism and would lower observed seismic velocities to those observed in large low shear velocity provinces. This work is the product of a collaboration with a fantastic group of geophysicists and geochemists that began at the CIDER workshop in summer 2014.