气候变化领域集成服务门户(CCPortal): Evolution of the Crustal and Upper Mantle Seismic Structure From 0–27 Ma in the Equatorial Atlantic Ocean at 2° 43′S

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DOI	10.1029/2020JB021390
	Evolution of the Crustal and Upper Mantle Seismic Structure From 0–27 Ma in the Equatorial Atlantic Ocean at 2° 43′S
	Vaddineni V.A.; Singh S.C.; Grevemeyer I.; Audhkhasi P.; Papenberg C.
发表日期	2021
ISSN	21699313
卷号	126 期号:6
英文摘要	We present seismic tomographic results from a unique seismic refraction and wide-angle survey along a 600 km long flow-line corridor of oceanic lithosphere ranging in age from 0 to 27 Ma in the equatorial Atlantic Ocean at 2° 43′S. The velocities in the crust near the ridge axis rapidly increase in the first 6 Myr and then change gradually with age. The upper crust (Layer 2) thickness varies between 2 and 2.4 km with an average thickness of 2.2 km and the crustal thickness varies from 5.6 to 6 km along the profile with an average crustal thickness of 5.8 km. At some locations, we observe negative velocity anomalies (∼−0.3 km/s) in the lower crust which could be either due to chemical heterogeneity in gabbroic rocks and/or the effects of fault related deformation zones leading to an increase in porosities up to 1.6% depending on the pore/crack geometry. The existence of a low velocity anomaly beneath the ridge axis suggests the presence of partial melt (∼1.3%) in the lower crust. Upper mantle velocities also remain low (∼7.8 km/s) from ridge axis up to 5 Ma, indicating a high temperature regime associated with mantle melting zone underneath. These results suggest that the evolution of the crust and uppermost mantle at this location occur in the first 10 Ma of its formation and then remains unchanged. Most of the structures in the older crust and upper mantle are fossilized structures and could provide information about past processes at ocean spreading centers. © 2021. The Authors.
英文关键词	evolution of lithosphere; mid-ocean ridges; tomography
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/187050
作者单位	Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France; GEOMAR Helmholtz Centre of Ocean Research Kiel, RD4-Marine Geodynamics, Kiel, Germany
推荐引用方式 GB/T 7714	Vaddineni V.A.,Singh S.C.,Grevemeyer I.,等. Evolution of the Crustal and Upper Mantle Seismic Structure From 0–27 Ma in the Equatorial Atlantic Ocean at 2° 43′S[J],2021,126(6).
APA	Vaddineni V.A.,Singh S.C.,Grevemeyer I.,Audhkhasi P.,&Papenberg C..(2021).Evolution of the Crustal and Upper Mantle Seismic Structure From 0–27 Ma in the Equatorial Atlantic Ocean at 2° 43′S.Journal of Geophysical Research: Solid Earth,126(6).
MLA	Vaddineni V.A.,et al."Evolution of the Crustal and Upper Mantle Seismic Structure From 0–27 Ma in the Equatorial Atlantic Ocean at 2° 43′S".Journal of Geophysical Research: Solid Earth 126.6(2021).