Origin of elements

Primitive meteorites contain micro minerals called presolar grains that were synthesized in various stellar environments before the formation of the solar system. Their chemical and isotopic compositions provide information on the environment (supernova explosion, AGB star, etc.) in which each mineral was formed. We measure isotopic compositions of trans-Fe elements in presolar grain-enriched fractions separated from chondrites to elucidate the origin of "elements".

Related papers

Yokoyama, T. and Walker, R.J.

Nucleosynthetic isotope variation of siderophile and chalcophile elements in the Solar System.
Reviews in Mineralogy and Geochemistry. vol. 81: Highly siderophile and strongly chalcophile elements in high temperature geochemistry and cosmochemistry, 107-160, 2016.

Yokoyama, T., Fukami, Y., Okui, W., Ito, N. and Yamazaki, H.

Nucleosynthetic Strontium Isotope Anomalies in Carbonaceous Chondrites.
Earth and Planetary Science Letters, 416, 46-55, 2015.

Yokoyama, T., Alexander, C.M.O'D. and Walker, R.J.

Osmium isotope anomalies in chondrites: Results for acid residues and related leachates.
Earth and Planetary Science Letters, 291, 48-59, 2010.

Qin, L., Alexander, C.M.O'D., Carlson, R.W., Horan, M.F. and Yokoyama, T.

Contributors to chromium isotope variation of meteorites.
Geochimica et Cosmochimica Acta, 74, 1122-1145, 2010.