[S-CG49] ハードロック掘削科学～陸上掘削から深海底掘削、そしてオマーン～

[SCG49-09] PGE and Os isotope variation in the gabbros and peridotites from the Oman DP drilling cores in the Samail ophiolite, Oman

*仙田 量子^1,2、鈴木 勝彦²、森下 知晃³、高澤 栄一⁴、道林 克禎⁵、Kelemen Peter⁶、Teagle Damon⁷、Coggon Jude⁷、Godard Marguerite⁸、The Oman DP Science Party (1.九州大学比較社会文化研究院、2.国立研究開発法人海洋研究開発機構・海底資源研究開発センター 、3.金沢大学理工研究域自然システム学系 、4.新潟大学理学部地質科学科、5.名古屋大学大学院環境学研究科、6.コロンビア大学、7.サウザンプトン大学、8.モンペリエ大学)

キーワード：オマーン掘削プロジェクト、はんれい岩、かんらん岩、オスミウム同位体組成、白金族元素存在度

It is well known that oceanic crust covers almost 70 % of Earth’s surface. It is formed at mid-ocean ridge and is subducted into mantle at convergent plate margin. This plate motion is pull many kinds of surface materials in inside the mantle and contributed to a global recycling system. However the details of the oceanic crusts and underlain upper mantle are still poor understanding. The construction of the oceanic crusts is defined by constructions of ophiolites which were the ancient oceanic plates exposed onto land.

To have better understandings of the oceanic crust, underlain upper-most mantle and related other things, the Oman Drilling Project by ICDP was done the drilling from 2016 to 2018 in Samail ophiolite, Oman. The Samail ophiolite in the northern part of Oman is the largest and having better exposed section of the oceanic lithosphere in the world.

We will report the preliminary results of the PGE abundances and Os isotope ratios in the whole-rock gabbros and mantle related peridotites from the drilling cores and compering to the data from the Oman surface data. These data will be help us to better understanding of the relationships between the oceanic crust and underlying upper mantle, mechanisms of making oceanic crust, and planning the future Mohole projects.