DOI: 10.1038/ngeo2270
论文题名: Plateau uplift in western Canada caused by lithospheric delamination along a craton edge
作者: Bao X. ; Eaton D.W. ; Guest B.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2014
卷: 7, 期: 11 起始页码: 830
结束页码: 833
语种: 英语
Scopus关键词: asthenosphere
; compressibility
; delamination
; Eocene
; magmatism
; plateau
; thermochronology
; uplift
; Canada
英文摘要: Continental plateaux, such as the Tibetan Plateau in Asia and the Altiplano-Puna Plateau in South America, are thought to form partly because upwelling, hot asthenospheric mantle replaces some of the denser, lower lithosphere1-4, making the region more buoyant. The spatial and temporal scales of this process are debated, with proposed mechanisms ranging from delamination of fragments to that of the entire lithosphere1-4. The Canadian Cordillera is an exhumed ancient plateau that abuts the North American Craton5. The region experienced rapid uplift during the mid-to-late Eocene, followed by voluminous magmatism6, a transition from a compressional to extensional tectonic regime7 and removal of mafic lower crust8. Here we use Rayleigh-wave tomographic and thermochronological data to show that these features can be explained by delamination of the entire lithosphere beneath the Canadian Cordillera. We show that the transition from the North American Craton to the plateau is marked by an abrupt reduction in lithospheric thickness by more than 150 km and that asthenosphere directly underlies the crust beneath the plateau region. We identify a 250-km-wide seismic anomaly about 150-250 km beneath the plateau that we interpret as a block of intact, delaminated lithosphere.We suggest that mantle material upwelling along the sharp craton edge9 triggered large-scale delamination of the lithosphere about 55 million years ago, and caused the plateau to uplift. © 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/106383
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 Geoscience, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada
Recommended Citation:
Bao X.,Eaton D.W.,Guest B.. Plateau uplift in western Canada caused by lithospheric delamination along a craton edge[J]. Nature Geoscience,2014-01-01,7(11)