R1: Characterization and description of minerals

[R1P-08] Minerals from gold and PGM placer deposits from the Rumoi area in Hokkaido, Japan

*Daisuke Nishio-Hamane¹, Katsuyuki Saito (1. ISSP, Tokyo Univ.)

Keywords:Qusongite, PtCu3, PGM, Gold, Rumoi

Neogene sedimentary rock is distributed in Rumoi area in Hokkaido. There is no distribution of ultramafic rocks, but gold and PGM placers can be collected in many places, suggesting that some ultramafic rocks was the source of sedimentary rock. In order to understand the characteristics of lost ultramafic body, we are investigating the minerals in the placer deposit. In this presentation, we report in particular the occurrence of qusongite, which is a natural tungsten carbide, and an unidentified mineral with PtCu₃ composition.