DOI: 10.1038/ngeo2062
论文题名: Mantle flow and multistage melting beneath the Galápagos hotspot revealed by seismic imaging
作者: Villagómez D.R. ; Toomey D.R. ; Geist D.J. ; Hooft E.E.E. ; Solomon S.C.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2014
卷: 7, 期: 2 起始页码: 151
结束页码: 156
语种: 英语
Scopus关键词: asthenosphere
; geodynamics
; hypothesis testing
; mantle convection
; melting
; mid-ocean ridge
; seismic tomography
; upwelling
; Ecuador
; Galapagos Islands
英文摘要: Some of Earth's largest magmatic provinces result from the interaction between mid-ocean ridges and near-ridge hotspots, which are hypothesized to overlie plumes of upwelling mantle. Geodynamic models predict that upwelling plumes are sheared by the motion of the overlying tectonic plates and can connect to a nearby mid-ocean ridge by shallow flow beneath thin, young lithosphere. Here we present seismic tomographic images of the upper 300 km of the mantle beneath the Galápagos Archipelago in the eastern Pacific Ocean. We observe a low-velocity anomaly, indicative of an upwelling plume, that is not deflected in the direction of plate motion. Instead, the anomaly tilts towards the mid-ocean ridge at depths well below the lithosphere. These characteristics of the plume-ridge connection beneath the Galápagos Archipelago are consistent with the presence of multiple stages of partial melting, melt extraction, and melt remixing within the plume and surrounding mantle. These processes affect the viscosity of the asthenosphere, alter the upwelling plume and influence the compositions of surface lavas. Our results imply that the coupling between the oceanic plate and plume upwelling beneath the Galápagos is weak. Multistage melting may similarly affect the geophysical and geochemical characteristics of other hotspots. © 2014 Macmillan Publishers Limited. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106448
Appears in Collections: 气候减缓与适应 科学计划与规划
There are no files associated with this item.
作者单位: Department of Geological Sciences, University of Oregon, Eugene, OR 97403, United States; Department of Geological Sciences, University of Idaho, Moscow, ID 83844, United States; Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, United States; ID Analytics, San Diego, CA 92128, United States
Recommended Citation:
Villagómez D.R.,Toomey D.R.,Geist D.J.,et al. Mantle flow and multistage melting beneath the Galápagos hotspot revealed by seismic imaging[J]. Nature Geoscience,2014-01-01,7(2)