Estimation of solidification temperature and pressure of granitoids in eastern Shimane Prefecture, southwest Japan

Kai Nakahashi; Satoshi SAITO

Presentation information

[E] Poster

S (Solid Earth Sciences ) » S-GC Geochemistry

[S-GC32] Volatiles in the Earth - from Surface to Deep Mantle

Sun. May 26, 2024 5:15 PM - 6:45 PM Poster Hall (Exhibition Hall 6, Makuhari Messe)

convener:Kenji Shimizu(Kochi Institute of Core Research, Japan Agency for Marine-Earth Science and Technology), Antonio Caracausi, Hirochika Sumino(Research Center for Advanced Science and Technology, The University of Tokyo), Takeshi Hanyu(Japan Agency for Marine-Earth Science and Technology, Research Institute for Marine Geodynamics)

5:15 PM - 6:45 PM

[SGC32-P05] Estimation of solidification temperature and pressure of granitoids in eastern Shimane Prefecture, southwest Japan

*Kai Nakahashi ¹, Satoshi SAITO¹ (1.Ehime university )

Keywords:Granite, Amphibole, single-phase Amphibole geotermobarometer, San-in belt

We applied the single-phase amphibole geothermometer (Putirka, 2016) and geobarometer (Redolfi and Renzulli,2012) for the Daito granodiorite, the Ogi quartz diorite and the Abire granodiorite from the San-in Belt in the inner zone of southwest Japan. We used chemical composition of inclusion-free brown-colored domain of each amphiboles assuming that they represent compositions at crystallization under suprasolidus conditions. The amphibole geothermobarometer yielded temperature and pressure values of 746 ± 15 ℃ and 78 ± 1 MPa for Daito granodiorite (n = 2, 1s), 779 ± 16 ℃ and 123±18 MPa for the Ogi quartz diorite(n = 6, 1 s), and 806 ± 7 ℃ and 161 ± 3 MPa (n = 2, 1 s) for the Abire granodiorite. Assuming the density of the upper continental crust to be 2.65 g/cm3, the depths of solidification of each rock body are ~3 km for Daito granodiorite, ~5 km for Ogi quartz diorite, and ~6 km for Abire granodiorite.