气候变化领域集成服务门户(CCPortal): The bent prolongation of the 85°E Ridge south of 5°N

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DOI	10.1016/j.tecto.2020.228457
	The bent prolongation of the 85°E Ridge south of 5°N – Fact or fiction?
	Altenbernd T.; Jokat W.; Geissler W.
发表日期	2020
ISSN	00401951
卷号	785
英文摘要	The enigmatic 85°E Ridge crosses the Bay of Bengal from north to south. Its strong gravity anomaly low is associated with Cretaceous hotspot volcanism. South of 5°N, the gravity low bends into a SW-NE orientation and continues as far SW as the Afanasy Nikitin Seamounts. This change has been interpreted to represent a bent hotspot track. We report new constraints on the crustal structure and genesis beneath the SW-trending gravity low based on new refraction seismic, reflection seismic, and shipborne gravity data. Our findings show that the crustal structure across the gravity low does not differ significantly from the adjacent, 4.5 to 7 km thick oceanic crust. No basement ridge, significant crustal thickening, or magmatic underplating were identified. We found no evidence for a southern prolongation of the 85°E Ridge. Instead, our P-wave velocity and density models reveal the gravity low to express a flexural basin, which is a result of widespread mid-Miocene to recent lithospheric deformation in the Indian Ocean. The ~25 mGal negative gravity anomaly is therefore not related to the passage of the Indian plate over a mantle plume, casting doubt on the possibility that volcanism at the Afanasy Nikitin Seamounts might be related to the same plume as the northern 85°E Ridge. The northern 85°E Ridge may have been generated at the northern prolongation of the 86°E Fracture Zone. © 2020 Elsevier B.V.
关键词	85°E ridge Bay of Bengal Gravity data Indian Ocean P-wave velocity model Refraction seismic data
英文关键词	Seismic waves; Seismology; Wave propagation; Crustal structure; Crustal thickenings; Flexural basins; Gravity anomalies; Lithospheric deformation; P-wave velocity; Reflection seismic; Refraction seismics; Submarine geology; crustal structure; crustal thickening; deformation; gravity anomaly; hot spot; Indian plate; mantle plume; underplating; volcanism; Afanasy Nikitin Seamount; Bay of Bengal; Indian Ocean
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/207703
作者单位	Alfred-Wegener-Institut für Polar-und Meeresforschung, Am Handelshafen 12, Bremerhaven, 27570, Germany
推荐引用方式 GB/T 7714	Altenbernd T.,Jokat W.,Geissler W.. The bent prolongation of the 85°E Ridge south of 5°N – Fact or fiction?[J],2020,785.
APA	Altenbernd T.,Jokat W.,&Geissler W..(2020).The bent prolongation of the 85°E Ridge south of 5°N – Fact or fiction?.Tectonophysics,785.
MLA	Altenbernd T.,et al."The bent prolongation of the 85°E Ridge south of 5°N – Fact or fiction?".Tectonophysics 785(2020).