[S-CG47] ハードロック掘削科学：陸上・深海底掘削、そしてオフィオライト

[SCG47-P03] オマーンオフィオライトマントル掘削コアに保存された海洋リソスフェア最上部のファブリック

*道林 克禎¹、柿畑 優季¹、夏目 樹¹ (1.名古屋大学 大学院環境学研究科 地球環境科学専攻 地球惑星科学系)

キーワード：オマーンオフィオライト、オマーン掘削プロジェクト、ファブリック、マントルセクション

Oman Ophiolite is the largest ophiolite that preserves structures of the crustal section including volcanic rock, sheeted dike, gabbro and the mantle section consisting of peridotites. Oman Drilling Project has drilled cores penetrating from the lower crust to the uppermost mantle including the crust–mantle transition zone. Structural characteristics within peridotites from 3 holes at BA site and 2 holes at CM site have been described during the Oman Drilling Project Phase 2 from 5^th August to 3^rd September, 2018 on board D/V Chikyu. The peridotites consiste of intensely serpentinized harzburgites containing elongated and aligned pyroxene grains and dunites. In this study, we observed peridotite textures derived from BA1B, BA3A and BA4A as well as CM1A and CM2B, and performed electron backscatter diffraction (EBSD) analyses to understand the characteristics of mantle flow. In EBSD analyses, peridotite textures have been reconstructed by extrapolation of the data, as they were obscured due to intense serpentinization.