[S-CG49] Hard-Rock Drilling Science: From Continental to Deep Sea Drilling, and Oman Project

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

*Ryoko Senda^1,2, Katsuhiko Suzuki², Tomoaki Morishita³, Eiichi TAKAZAWA⁴, Katsuyoshi Michibayashi⁵, Peter B Kelemen⁶, Damon AH Teagle⁷, Jude Ann Coggon⁷, Marguerite Godard⁸, The Oman DP Science Party (1.Faculty of Social and Cultural Studies, Kyushu University, 2.Research and Development Center for Submarine Resources, JAMSTEC, 3.School of Natural System, Colleage of Science and Technology, Kanazawa University, 4.SDepartment of Geology, Faculty of Science, Niigata University, 5.Department of Earth and Planetary Sciences, Nagoya University, 6.Columbia University, 7.University of Southampton, 8.Géosciences Montpellier)

Keywords:Oman DP, gabbro, peridotite, Os isotope ratio, PGE abundance

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.