DOI: 10.1038/ngeo2662
论文题名: Formation of lower continental crust by relamination of buoyant arc lavas and plutons
作者: Kelemen P.B. ; Behn M.D.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2016
卷: 9, 期: 3 起始页码: 197
结束页码: 205
语种: 英语
Scopus关键词: continental crust
; delamination
; island arc
; lamination
; lava
; lower crust
; pluton
; subduction
; trace element
; Alaska
; Aleutian Islands
; Izu-Bonin Arc
; Kohistan
; Pacific Ocean
; Talkeetna Mountains
; United States
英文摘要: The formation of the Earth's continents is enigmatic. Volcanic arc magmas generated above subduction zones have geochemical compositions that are similar to continental crust, implying that arc magmatic processes played a central role in generating continental crust. Yet the deep crust within volcanic arcs has a very different composition from crust at similar depths beneath the continents. It is therefore unclear how arc crust is transformed into continental crust. The densest parts of arc lower crust may delaminate and become recycled into the underlying mantle. Here we show, however, that even after delamination, arc lower crust still has significantly different trace element contents from continental lower crust. We suggest that it is not delamination that determines the composition of continental crust, but relamination. In our conceptual model, buoyant magmatic rocks generated at arcs are subducted. Then, upon heating at depth, they ascend and are relaminated at the base of the overlying crust. A review of the average compositions of buoyant magmatic rocks-lavas and plutons-sampled from the Aleutians, Izu-Bonin-Marianas, Kohistan and Talkeetna arcs reveals that they fall within the range of estimated major and trace elements in lower continental crust. Relamination may thus provide an efficient process for generating lower continental crust. © 2016 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/106050
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Department of Earth and Environmental Sciences, Columbia University, LDEO, Palisades, NY, United States; Department of Geology and Geophysics, Woods Hole Oceanographic Institute, Woods Hole, MA, United States
Recommended Citation:
Kelemen P.B.,Behn M.D.. Formation of lower continental crust by relamination of buoyant arc lavas and plutons[J]. Nature Geoscience,2016-01-01,9(3)