research

REE partitioning between Fe-Mn oxyhydroxide deposits and seawater

The experimental and theoretical study of REE partitioning between ferromanganese nodules and seawater.

Ce anomaly and Y/Ho ratio of ferromanganese nodules in Pacific and Antarctic Ocean
Linearly-related Ce anomaly and Co/(Ni+Cu) ratio of ferromanganese nodules in Pacific and Antarctic Ocean
Reproductive experiment of REE partitioning between ferromanganese nodules and deep sea water
Determination of REE-carbonate ion complexation constants
Oxidative process of Ce(IIII) to Ce(IV) by δ-MnO2
RSPET analyses of REE distribution coefficients of the experimental data and field ones and of REE(III)-carbonate complexation constants.

Regional spatial distribution patterns of 53 elemental concentrations on the surface of Japanese Island Arc region.

Terrestrial geochemical maps: Nationwide geochemical maps using stream sediments (1 sample/100–120 km2).
Marine (coastal sea) geochemical maps: Nationwide geochemical maps using coastal sea sediments (1 sample/60–80 km2).
High-density geochemical maps: Geochemical maps using stream sediments around the metropolitan region (1 sample/10 km2).
Sr-isotopic geochemical map: Nationwide geochemical maps using stream sediments (1 sample/100–120 km2).

Determination of the local structure of 3d transition metals and rare earth elements in amorphous materials (Fe hydroxide and Mn dioxide) and humic substances using synchrotron X-ray in KEK-PF. The uptake process of minor elements of amorphous materials and humic substances from solution is interpreted from the point of view of chemical species, valence state, and local coordination structures.

Speciation of metals in soil, stream and marine sediments

Speciation study of metals such as 3d transition metals, Zn, and Pb in soils, stream sediments and marine sediments using a sequential extraction procedure and IR and XAFS spectroscopy methods.

Aeolian Dust

Investigation of physical and chemical properties of aeolian dust by the collaboration of Japan and China of the observation network. The dust samples are being collected in Japan (Okinawa, Fukuoka, Nagoya, and Tsukuba) and China (Beijing, Qingdao and Hefei). Our studies of aeolian dust from the point of view of grain-size distribution, morphological properties, mineralogical and chemical compositions. (The project was completed in March, 2005.)