Susumu Umino

My fields of specialty are igneous petrology and physical volcanology, especially relevant to the magma genesis and mantle evolution through subduction initiation. I started my career in geology, petrology and experiments on boninite from type locality in Bonin Islands. After a one-year JSPS postdoctoral fellow, I got an academic position in Shizuoka University for twenty years and then moved to Kanazawa University. Studies on melt inclusions in chromite derived from boninite are very exciting and fruitful. With Keitaro Kitamura, Kyoko Kanayama and Osamu Ishizuka, I demonstrated the coexistence of high-silica and low-silica boninite magmas, which gave critical constraints on the magma genesis and the development of mantle wedge during the subduction initiation along the Izu-Bonin-Mariana protoarc. Modelling of Nd-Hf-Os isotopic ratios of these boninites and protoarc basalts indicated the different ages and origins of the boninite sources.
While I was a PhD student, I engaged in a geological mapping project by the Oman government. In collaboration with Sumio Miyashita and Shoji Arai, I have been working on the Oman Ophiolite and studied volcanic processes of the paleo-ridge system and its transformation to an ephemeral arc system. In collaboration with Tsuyoshi Ishikawa, boninite was for the first time discovered and reported from the Oman Ophiolite. With Yuki Kusano, Keitaro Kitamura and Tsuyoshi Ishikawa, I have been working on magma genesis and evolution of the mantle from paleo-spreading to juvenile arc stages. We have shown how the Oman protoarc mantle resemble and differ in varying T-P-X conditions compared to the Izu-Bonin-Mariana protoarc mantle.
In addition to submersible dives to seamounts off Bonin-Mariana forearc, Hawaii and the East pacific Rise, I joined a series of ODP-IODP expeditions to Hole 504B and 1256D, which drilled deeply into the intact oceanic crust. Comparative studies of structures of the intermediate- and fast-spread crust clearly indicate how the upper crustal structure is determined by partitioning of strain due to plate movement into faults and dikes.
With the experience of studying the present and past oceanic crust, I have been promoting a project MoHole, ultradeep drilling through the entire oceanic lithosphere and the Moho to the mantle, to recover pristine, in-situ mantle materials for the first time in human history, by the Deep Sea Scientific Drilling Vessel CHIKYU as IODP platform.