2021 Annual Meeting of Japan Association of Mineralogical Sciences (JAMS)

Presentation information

Poster presentation

R7: Petrology, Mineralogy and Economic geology (Joint Session with Society of Resource Geology)

Fri. Sep 17, 2021 9:30 AM - 6:30 PM ePoster Session

9:30 AM - 6:30 PM

[R7P-01] The formation of ultra-refractory peridotite from the Kamuikotan belt, Hokkaido

[Presentation award entry]

*Ikuya Nishio1, Tomoaki Morishita1, Keita Itano1, Akihiro Tamura1, Yuji Ichiyama2, Shun Takamizawa2, Shoji Arai1 (1. Kanazawa Uni., 2. Chiba Uni.)

Keywords:Ultra-refractory, Peridotite, Mantle, Olivine, Orthopyroxene


Ultra-refractory peridotites characterized by high forsterite contents and Cr# of spinel were exposed in Takadomari and Horokanai complex from the Kamuikotan belt which represents the Cretaceous subduction zone (Tamura et al., 1999; Takeshita et al., 2018). We re-examine the origin of these peridotites using the mineral chemistry to understand the formation of ultra-refractory peridotites. The mineral chemistry indicates that the Takadomari and Horokanai peridotites are the most depleted peridotites on Earth and formed in the early stage of subduction (Umino et al., 2015).