[S-CG54] 海域火山

[SCG54-P12] ケルマディック弧キブルホワイト火山のマグネシアン安山岩

平井 康裕¹、*田村 芳彦¹、佐藤 智紀¹、宮崎 隆¹、Chang Qing¹、Vaglarov Bogdan¹、木村 純一¹、Hoernle Kaj²、Werner Reinhard²、Hauff Folkmar²、Timm Christian² (1.海洋研究開発機構　海域地震火山部門、2.GEOMAR)

キーワード：ケルマディック弧、マグネシアン安山岩、大陸、安山岩

This study presents the petrology of volcanic rocks dredged from Kibblewhite volcano in the Kermadec arc during the RV SONNE SO-255 expedition in 2017. Magma types range from andesit to rhyolite and we focus on magnesian andesites from the northeastern flank of this volcano. We conclude that the magnesian andesites are produced by direct melting of the uppermost mantle of the Kermadec arc. The thin crustal thickness of the Kermadec ard should yield low pressure conditions in teh uppermost mantle, allowing the sub-arc mantle to generate primary andesitic melts.