Tatsuhiko Kawamoto

Tatsuhiko Kawamoto



Tatsuhiko Kawamoto


Primary department

Org1 Org2 Org3 Job title
Graduate School of Science Institute for Geothermal Sciences   Assistant Professor


kawamoto (at) bep.vgs.kyoto-u.ac.jp





Personal Profile

I studied field volcanology at undergraduate school, and then petrology and petrochemistry of magma chamber processes at graduate school. After I got PhD, I started conducting high-pressure and high-temperature experiments to understand the effects of water on the melting temperature and the partial melts chemistry. For recent years, I have conducted in-situ or direct observation experiments to understand behaviors of aqueous fluids and magmas in the depths of the earth and also have investigated fluid inclusions in mantle peridotites and high-pressure metamorphic rocks.


Research Topics

I study aqueous fluids and magmas in the depths of the earth. I use two types of approaches to understand what takes place in subduction zones. One is to conduct in-situ or direct observation under high-pressure and high-temperature conditions. The other is observation and analysis of fluid inclusions in mantle peridotites and high-pressure metamorphic rocks. So far every C-H-O fluids have the salinity similar to that of seawater.


Overview of your research

I have studied magmas and aqueous fluids for thirty years. I am fond of the following hypotheses including:
(1) Saline fluids play important roles to transfer large-ion-lithophile elements that characterize the chemistry of subduction zone magmas.
(2) Subduction-zone magmas are produced by separation processes of supercritical fluids derived from the downgoing slab.
(3) Arc-basalts are water-saturated and initially have 6 or more weight % H2O.
(4) Silicate compositions dissolved in aqueous fluids in the mantle conditions have more Mg/Si as increasing pressure.
(5) Hydrous mantle transition zone was formed by crystallization of hydrous wadsleyite and ringwoodite from a hydrous magma ocean. Such hydrous transition zone produced komatiite magmas that erupted mainly during Archean. The present subducting slab can not delivered much amounts of water beyond 250 km; therefore, the present mantle transition zone may be almost anhydrous.
(6) Andesite-dacite-rhyolite magmas can be formed by fractional crystallization or partial melting of hydrous basalts. Arc basalt and high Mg andesite can be formed by partial melting of hydrous mantle peridotites.
(7) Honeycomb plagioclase coexisting with dusty-zone plagioclase can be formed by rapid crystallization from supercooled magmas.


Fields of research (key words)



Message from the Researcher

Researchers have a privilege to pursue his/her own research targets as he/she likes. In order to do that, we need to have knowledge, technical skills, and wisdom. Practically we need to have the following:
(1) English language to read, write and communicate.
(2) We do not need much knowledge about mathematics, but we need skill to think logically. Intuition can be important, though.
(3) Careful high school students may do experiments and observation as we do; however, when those things go wrong, they may not find a way to overcome a problem nor continue to pursue the problem. This is because they do not know why we need to attack this target. We need to understand the importance to understand our own research targets.
(4) Natural phenomena are complex. We need to extract a research target from them.