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

[R7P-11] Antient mantle melting event left in peridotite xenoliths from Tahiti Island

*Norikatsu Akizawa¹, Akira Ishikawa², Tetsu Kogiso³ (1. Tokyo Univ. AORI, 2. Earth and Planetary Sci., Tokyo Tech., 3. Grad. Sch. Hum. and Environ. Stud., Kyoto Univ.)

Keywords:Ancient mantle domain, Re-Os isotopes, highly siderophile elements, harzburgite, dunite

Abyssal peridotites are fragments of the uppermost mantle in the oceanic region. They record melting events at the ridges and paleo-melting events somewhere other than the ridges. However, the understanding of paleo-melting events are not sufficiently advanced since the occurrence of the abyssal peridotites are limited in the oceanic region. Here, we attempted to elucidate the paleo-melting events and timing by analyzing the Os isotope composition and highly siderophile element compositions of peridotite xenoliths from Tahiti, Society Islands.