The nature of two seismically detected, gigantic structures at Earth's core-mantle boundary (LLSVPs) and associated hot convection plumes that feed cataclysmic flood basalt eruptions remain enigmatic. Flood basalt formations are critical for the understanding of LLSVPs as they are likely to contain LLSVP material. GEMS focuses on geochemical mapping and geodynamic modelling of the plumes that formed flood basalts in Africa and Antarctica 183-132 million years ago. Geochemical tracers of silicates and metals (e.g. short-lived Hf-W ja Sm-Nd isotopes) that are likely to be present in deep mantle are used to portrait the plumes and their LLSVP sources that may include relics of Earth's initial (Hadean >4 Gyr old) materials. Examination of the ancient flood basalts and related presently active volcanic hotspots can unravel the poorly understood dynamic evolution of very long-lived mantle plumes. GEMS has potential for breakthroughs in studies of plumes, deep mantle, and Earth's evolution.

2025

2029