DOI: 10.1002/2015GL066625
论文题名: Crustal seismic structure beneath the source area of the Columbia River flood basalt: Bifurcation of the Moho driven by lithosphere delamination
作者: Gao H.
刊名: Geophysical Research Letters
ISSN: 0094-8412
EISSN: 1944-8143
出版年: 2015
卷: 42, 期: 22 起始页码: 9764
结束页码: 9771
语种: 英语
英文关键词: bifurcating Moho
; Columbia River basalt
; delamination
; full-wave seismic tomography
; teleseismic receiver functions
; Wallowa Mountains
Scopus关键词: Basalt
; Bifurcation (mathematics)
; Delamination
; Floods
; Rivers
; Seismology
; Bifurcating Moho
; Columbia river basalts
; Seismic tomography
; Teleseismic receiver functions
; Wallowa Mountains
; Structural geology
; ambient noise
; azimuth
; bifurcation
; crustal structure
; delamination
; flood basalt
; latitude
; lithosphere
; lower crust
; Moho
; seismic tomography
; slab
; source parameters
; teleseismic wave
; topographic mapping
; uplift
; upper crust
; upper mantle
; California
; Columbia River
; Farallon Islands
; Oregon
; United States
; Wallowa Mountains
英文摘要: The source area of the ~16 Ma Columbia River flood basalt eruptions originated beneath the Wallowa Mountains in northeast Oregon, with a distinct circular pattern of topographic uplift. Teleseismic receiver functions reveal two layers between latitude 45.5° and 46.5° beneath north of the Wallowas, one at 25 km depth and the other one at 45 km depth. A new full-wave ambient noise tomography model shows a circular anomaly, which is seismically fast in the upper crust and slow from lower crust to uppermost mantle in comparison with the surroundings, coincident with the circular pattern of the Wallowas. The seismic structures suggest that delamination of the Farallon lithosphere initiated the basalt eruptions and, consequently, modified the lowermost crust, forming a new shallow Moho. The Farallon slab is probably detached directly beneath the Wallowas while being maintained at the northern edge of the Wallowas, corresponding to the deeper interface. Key Points Teleseismic receiver functions are highly complex and azimuthally varying Bifurcating Moho is detected north of the Columbia River basalt eruptions Lithosphere delamination triggered the basalt eruptions and modified the lower crust. © 2015. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84956895516&doi=10.1002%2f2015GL066625&partnerID=40&md5=91f8c7a218a885c6723e521bfd53a713
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/8028
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: Department of Geosciences, University of Massachusetts Amherst, Amherst, MA, United States
Recommended Citation:
Gao H.. Crustal seismic structure beneath the source area of the Columbia River flood basalt: Bifurcation of the Moho driven by lithosphere delamination[J]. Geophysical Research Letters,2015-01-01,42(22).