TY - JOUR
T1 - Petrology, geochemistry, and geochronology of plutonic rocks from the present Southwest Indian Ridge
T2 - Implications for dropstone distribution in the Indian Ocean
AU - Sato, Hiroshi
AU - Machida, Shiki
AU - Senda, Ryoko
AU - Sato, Keiko
AU - Kumagai, Hidenori
AU - Hyodo, Hironobu
AU - Yoneda, Shigekazu
AU - Kato, Yasuhiro
N1 - Funding Information:
We would like to thank the captain, crew, and scientific party on board the Research Vessel Hakuho Maru during cruise KH-09-5. We thank J. Arita and K. Komiyama for preparing thin sections and whole-rock samples at Senshu University. S.M. and Y.K. are indebted to Y. Itabashi and K. Yasukawa for their invaluable assistance with the preparation of samples for ICP-MS and TIMS analyses. We acknowledge T. Hokada and A. Kamei for their valuable suggestions on metamorphic and plutonic rocks from East Antarctica. We appreciate the constructive reviews and editorial comments of M. Satish-Kumar and three anonymous reviewers. The research was supported by JSPS KAKENHI Grant Number JP20540448 and JP17H06318 The following programs supported this research: FY2010 and 2020 Research Fellowship Program of Senshu University; Cooperative short-term visiting scientist research systems of Atmosphere and Ocean Research Institute, The University of Tokyo. Neutron irradiation for the Ar?Ar age experiment was performed through the Visiting Research Program of the Research Reactor Institute of Kyoto University. Maps were drawn using the GMT software (Wessel et al. 2019).
Funding Information:
We would like to thank the captain, crew, and scientific party on board the Research Vessel Hakuho Maru during cruise KH-09-5. We thank J. Arita and K. Komiyama for preparing thin sections and whole-rock samples at Senshu University. S.M. and Y.K. are indebted to Y. Itabashi and K. Yasukawa for their invaluable assistance with the preparation of samples for ICP-MS and TIMS analyses. We acknowledge T. Hokada and A. Kamei for their valuable suggestions on metamorphic and plutonic rocks from East Antarctica. We appreciate the constructive reviews and editorial comments of M. Satish-Kumar and three anonymous reviewers. The research was supported by JSPS KAKENHI Grant Number JP20540448 and JP17H06318 The following programs supported this research: FY2010 and 2020 Research Fellowship Program of Senshu University; Cooperative short-term visiting scientist research systems of Atmosphere and Ocean Research Institute, The University of Tokyo . Neutron irradiation for the Ar–Ar age experiment was performed through the Visiting Research Program of the Research Reactor Institute of Kyoto University. Maps were drawn using the GMT software ( Wessel et al., 2019 ).
Publisher Copyright:
© 2021 The Author(s)
PY - 2021/9
Y1 - 2021/9
N2 - 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.
AB - 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.
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U2 - 10.1016/j.polar.2021.100725
DO - 10.1016/j.polar.2021.100725
M3 - Article
AN - SCOPUS:85108952952
VL - 29
JO - Polar Science
JF - Polar Science
SN - 1873-9652
M1 - 100725
ER -
