Postdoctoral Fellow, NASA
Mantle and crustal geochemistry; cosmochemistry; planetary science, meteorites; mineral-melt trace element partitioning; geochemical modeling; development of REE geothermobarometer
B.S., Geology, Stony Brook University, 2010
Ph.D., Geological Sciences, Brown University, 2016
Kei Shimizu is interested in the evolution of the Earth’s mantle and crust through the history of the Earth. His most recent research interests are in understanding the origin of volatiles (e.g., H and C) in chondrites, that may have accreted volatiles to Earth. He currently investigates this using geochemical analysis of magmas generated by melting of the Earth’s upper mantle at mid-ocean ridges (mid-ocean ridge basalts or MORBs) to better constrain the processes that the magmas have undergone (degree of mantle melting, melt mixing, fractional crystallization, and volatile degassing) and the composition of the Earth's upper mantle. Part of his Ph.D. dissertation research focused on understanding the chemical variation in MORBs generated at the East Pacific Rise (EPR) through new geochemical analysis and modeling and its implications for the volatile content (C, H, F, Cl, S) of the Pacific upper mantle.
Shimizu also investigates mineral-melt trace element partitioning by using experimental partitioning data to developing models of trace element partitioning between minerals and melts. Using the model and natural data, he looks for chemical signatures of melting/fractional crystallization of minerals in magmas. Part of his Ph.D. dissertation research focused on development of rare earth element (REE) partitioning models between amphibole and silicate melt to better understand arc magma differentiation and its implications for the composition of the continental crust.
At DTM, Shimizu will work on measuring H concentration and isotopic composition in glasses and nominally anhydrous minerals in chondrules and CAIs. His goal is to place better constraints on H2 and H2O partial pressures and H isotopic composition during chondrule and CAI formation, after understanding and ruling out potential parent body modification.