サトウ　ヒロシ   SATO Hiroshi   佐藤 暢    所属   専修大学  経営学部    職種   教授
言語種別	英語
発行・発表の年月	2021/06/26
形態種別	研究論文（学術雑誌）
査読	査読あり
標題	Petrology, geochemistry, and geochronology of plutonic rocks from the present Southwest Indian Ridge: Implications for dropstone distribution in the Indian Ocean
執筆形態	共著
掲載誌名	Polar Science
掲載区分	国外
出版社・発行元	Elsevier
巻・号・頁	28
担当区分	筆頭著者,責任著者
著者・共著者	Hiroshi Sato◎, Shiki Machida, Ryoko Senda, Keiko Sato, Hidenori Kumagai, Hironobu Hyodo, Shigekazu Yoneda, Yasuhiro Kato
概要	We recovered sedimentary and plutonic rocks from the off-ridge portion of the Southwest Indian Ridge (37°00.02ʹ E, 44°49.73ʹ S, 2165 m deep). The petrography, geochemistry, and geochronology of these plutonic rocks were analyzed. Ar-Ar dating of biotite in the plutonic rocks yielded early Paleozoic ages of approximately 475 and 490 Ma, indicating that these rocks are likely related to Antarctic orogenies during the late Neoproterozoic to early Paleozoic. In addition, the samples exhibited trace element compositions and low initial εNd values (-8 and -12) similar to those of rocks from western Dronning Maud Land and the Transantarctic Mountains, Antarctica. Such similarities suggest that these plutonic rocks from the off-ridge portion of the Southwest Indian ridge were derived from western Dronning Maud Land or the Transantarctic Mountains and deposited by melting icebergs as dropstones.
DOI	10.1016/j.polar.2021.100725
researchmap用URL	https://www.sciencedirect.com/science/article/pii/S1873965221001146