气候变化领域集成服务门户(CCPortal): Remagnetization of Red Beds on the Tibetan Plateau: Mechanism and Diagnosis

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DOI	10.1029/2020JB020068
	Remagnetization of Red Beds on the Tibetan Plateau: Mechanism and Diagnosis
	Huang W.; Jackson M.J.; Dekkers M.J.; Solheid P.; Zhang Y.; Li S.; Guo Z.; Ding L.
发表日期	2020
ISSN	21699313
卷号	125 期号:8
英文摘要	Red beds are important targets for paleomagnetic studies, yet discriminating secondary chemical remanent magnetization (CRM) from primary depositional remanent magnetization (DRM) in them remains challenging. Here we reanalyze the thermal demagnetization data of and conduct comprehensive rock magnetic, Mössbauer spectroscopic and petrographic studies on red beds from four Cenozoic basins on the eastern Tibetan Plateau (China): the Gongjue, Nangqian, Shanglaxiu, and Jinggu basins. The red beds in the latter two basins are remagnetized, as are most Nangqian red beds. The Gongjue red beds and some Nangqian red beds retain a DRM. Our results reveal that detrital (titano)magnetite and hematite are well preserved in red beds retaining the DRM, whereas remagnetized red beds contain large amounts of authigenic hematite and goethite with detrital Fe-bearing minerals strongly altered. Postdepositional diagenetic alteration induced by heating and/or fluid circulation related to magmatism and/or crustal deformation is probably the main reason for the remagnetization. Hematite carrying the CRM in remagnetized red beds has wide distribution of grain size and unblocking temperature spectra, while hematite carrying the DRM is usually coarse and has confined unblocking temperature spectrum. This can be used as a criterion for diagnosing remagnetization. Nanoscale goethite appears to occur only in remagnetized red beds: another sensitive criterion for discriminating CRM from DRM. These property-based criteria constrain the origin of the NRM in red beds better than the classic paleomagnetic field tests. Our research emphasizes that integrated rock magnetic, Mössbauer spectroscopic and petrographic studies provide robust tools to diagnose remagnetization in red beds. © 2020. American Geophysical Union. All Rights Reserved.
英文关键词	red bed, remagnetization, hematite, goethite, mechanism, diagnosis
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187655
作者单位	Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, and Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, China; Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY, United States; Institute for Rock Magnetism, Department of Earth Sciences, University of Minnesota, Minneapolis, MN, United States; Department of Earth Sciences, Utrecht University, Utrecht, Netherlands; The First Monitoring and Application Center, China Earthquake Administration, Tianjin, China; Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom; Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences, Peking University, Beijing, China
推荐引用方式 GB/T 7714	Huang W.,Jackson M.J.,Dekkers M.J.,et al. Remagnetization of Red Beds on the Tibetan Plateau: Mechanism and Diagnosis[J],2020,125(8).
APA	Huang W..,Jackson M.J..,Dekkers M.J..,Solheid P..,Zhang Y..,...&Ding L..(2020).Remagnetization of Red Beds on the Tibetan Plateau: Mechanism and Diagnosis.Journal of Geophysical Research: Solid Earth,125(8).
MLA	Huang W.,et al."Remagnetization of Red Beds on the Tibetan Plateau: Mechanism and Diagnosis".Journal of Geophysical Research: Solid Earth 125.8(2020).