Magnetostratigraphic and environmental implications of greigite (Fe3S4) formation from Hole U1433A of the IODP Expedition 349, South China Sea

Duan, Zongqi1,2; Liu, Qingsong2,3; Gai, Congcong1; Zhao, Xixi4,5

2017-12

10.1016/j.margeo.2017.02.008

MARINE GEOLOGY   影响因子和分区

0025-3227

1872-6151

A detailed magnetic analysis has been done on sedimentary core of the International Ocean Discovery Program (IODP) Site U1433A during Leg 349 in the South China Sea (SCS). Results show that dominant carriers of the natural remanent magnetization are greigite and (titano) magnetite. The major shift in both declination and inclination at similar to 185 mbsf is assigned to the Matuyama-Brunhes reversal boundary (similar to 0.773 Ma). Constrained by biostratigraphic ages, variations in magnetic parameters of the core can be well correlated to the marine oxygen isotope record at glacial/interglacial cycles. Low values of concentration-dependent magnetic parameters correspond to the interglacials, and vice versa. During the interglacial periods, the dominant magnetic minerals are detrital (titano) magnetite and have relatively coarser grain sizes, while fine-grained greigites dominate the glacial periods. This indicates that during the glacials, greigite prevails at the anoxic condition with amount of terrigenous iron oxide caused by the disconnection between the SCS and the Indian Ocean and the exposure of shelf, but digenesis is suppressed at the opposite environment by the high sea level (interglacials). Thus, the preservation/sulfide process of (titano) magnetite is intimately related to the transformation of sea level changes with the monsoon-related rainfall caused by the glacial/interglacial variation. (C) 2017 Elsevier B.V. All rights reserved.

Magnetostratigraphy Environmental magnetism Glacial/interglacial cycle IODP Expedition 349 Site U1433 South China Sea

SCI ; EI

英语

通讯

China Postdoctoral Science Foundation[2014M561047]

Geology ; Oceanography

Geosciences, Multidisciplinary ; Oceanography

WOS:000423003500008

ELSEVIER SCIENCE BV

20171003407874

Glacial geology ; Iron oxides ; Magnetite ; Sea level

Oceanography, General:471.1 ; Geology:481.1 ; Magnetism: Basic Concepts and Phenomena:701.2 ; Inorganic Compounds:804.2

GEOSCIENCES

Web of Science

1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China
2.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Geol, Qingdao, Peoples R China
3.Southern Univ Sci & Technol, Dept Marine Sci & Engn, Shenzhen 518055, Peoples R China
4.Tongji Univ, State Key Lab Marine Geol, Shanghai 200092, Peoples R China
5.Univ Calif Santa Cruz, Dept Earth & Planetary Sci, Inst Geophys & Planetary Phys, Santa Cruz, CA 95064 USA

Duan, Zongqi,Liu, Qingsong,Gai, Congcong,et al. Magnetostratigraphic and environmental implications of greigite (Fe3S4) formation from Hole U1433A of the IODP Expedition 349, South China Sea[J]. MARINE GEOLOGY,2017,394:82-97.

Duan, Zongqi,Liu, Qingsong,Gai, Congcong,&Zhao, Xixi.(2017).Magnetostratigraphic and environmental implications of greigite (Fe3S4) formation from Hole U1433A of the IODP Expedition 349, South China Sea.MARINE GEOLOGY,394,82-97.

Duan, Zongqi,et al."Magnetostratigraphic and environmental implications of greigite (Fe3S4) formation from Hole U1433A of the IODP Expedition 349, South China Sea".MARINE GEOLOGY 394(2017):82-97.