DOI: 10.1002/2014GL062521
论文题名: Seismic observation of an extremely magmatic accretion at the ultraslow spreading Southwest Indian Ridge
作者: Li J. ; Jian H. ; Chen Y.J. ; Singh S.C. ; Ruan A. ; Qiu X. ; Zhao M. ; Wang X. ; Niu X. ; Ni J. ; Zhang J.
刊名: Geophysical Research Letters
ISSN: 0094-8758
EISSN: 1944-8489
出版年: 2015
卷: 42, 期: 8 起始页码: 2656
结束页码: 2663
语种: 英语
英文关键词: magmatic accretion
; seismic tomography
; ultraslow spreading ridge
Scopus关键词: Seismic prospecting
; Seismographs
; Seismology
; Structural geology
; Volcanoes
; Crustal thickness
; Low-velocity anomaly
; Magmatic accretion
; Seismic observation
; Seismic tomography
; Southwest Indian Ridge
; Tectonic process
; Ultra-slow spreading
; Tectonics
; accretion
; lithosphere
; magmatism
; oceanic crust
; seismic data
; tectonic structure
; Indian Ocean
; Southwest Indian Ridge
英文摘要: The oceanic crust is formed by a combination of magmatic and tectonic processes at mid-ocean spreading centers. Under ultraslow spreading environment, however, observations of thin crust and mantle-derived peridotites on the seafloor suggest that a large portion of crust is formed mainly by tectonic processes, with little or absence of magmatism. Using three-dimensional seismic tomography at an ultraslow spreading Southwest Indian Ridge segment containing a central volcano at 50°28′E, here we report the presence of an extremely magmatic accretion of the oceanic crust. Our results reveal a low-velocity anomaly (-0.6 km/s) in the lower crust beneath the central volcano, suggesting the presence of partial melt, which is accompanied by an unusually thick crust (∼9.5 km). We also observe a strong along-axis variation in crustal thickness from 9.5 to 4 km within 30-50 km distance, requiring a highly focused melt delivery from the mantle. We conclude that the extremely magmatic accretion is due to localized melt flow toward the central volcano, which was enhanced by the significant along-axis variation in lithosphere thickness at the ultraslow spreading Southwest Indian Ridge. ©2015. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84929503627&doi=10.1002%2f2014GL062521&partnerID=40&md5=cb62bb3db57fc7045a86e748724930d5
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/8374
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: Second Institute of Oceanography, State Oceanic Administration, Hangzhou, China
Recommended Citation:
Li J.,Jian H.,Chen Y.J.,et al. Seismic observation of an extremely magmatic accretion at the ultraslow spreading Southwest Indian Ridge[J]. Geophysical Research Letters,2015-01-01,42(8).