气候变化领域集成服务门户(CCPortal): The Upper Mantle Structure of Northwestern Canada From Teleseismic Body Wave Tomography

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DOI	10.1029/2019JB018837
	The Upper Mantle Structure of Northwestern Canada From Teleseismic Body Wave Tomography
	Estève C.; Audet P.; Schaeffer A.J.; Schutt D.; Aster R.C.; Cubley J.
发表日期	2020
ISSN	21699313
卷号	125 期号:2
英文摘要	The Northern Canadian Cordillera (NCC) is an actively deforming orogenic belt in northwestern Canada. Geochemical and geophysical data show that the NCC is underlain by a thin and hot lithosphere, in contrast with the adjacent cold and thick cratonic lithosphere to the east. This juxtaposition of cold/hot and thick/thin lithosphere across a narrow transition zone has important implications for regional geodynamics. The recent deployment of USArray Transportable Array and other seismic stations across Alaska, USA, and northwestern Canada allows us to image lithosphere and upper mantle three-dimensional seismic velocity structure at significantly improved resolution. Our model reveals a broad high-velocity anomaly across northern Yukon and Northwest Territories, which is interpreted as buried cratonic lithosphere and which we refer to as the Mackenzie craton. Another prominent high-velocity anomaly is imaged beneath northeastern British Columbia and is interpreted to indicate cratonic lithosphere beneath the Northern Rocky Mountains. These two mechanically strong lithospheric blocks, also suggested by regional magnetic data, are interpreted to buttress the ends of the Mackenzie Mountains fold and thrust belt, guiding intervening cordilleran mantle flow toward the Canadian Shield and controlling the arcuate geometry of the Mackenzie Mountains fold and thrust belt. Both (Formula presented.) and (Formula presented.) wave models also reveal the signature of a northward dipping, subducting Wrangell slab across the southern region of the Alaska/Yukon border. Strong (Formula presented.) and (Formula presented.) wave velocity contrasts across the Tintina Fault suggest that it is a lithosphere-scale shear zone that extends into the upper mantle beneath the NCC and demarcates distinct regions of lithospheric mantle. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	body wave tomography; cratonic lithosphere; Northern Canadian Cordillera; Tintina Fault
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/187985
作者单位	Department of Earth and Environmental Sciences, University of Ottawa, Ottawa, ON, Canada; Geological Survey of Canada, Pacific Division, Natural Resources Canada, Sidney, BC, Canada; Department of Geosciences, Colorado State University, Fort Collins, CO, United States; Centre for Northern Innovation in Mining, Yukon College, Whitehorse, Yukon, Canada
推荐引用方式 GB/T 7714	Estève C.,Audet P.,Schaeffer A.J.,et al. The Upper Mantle Structure of Northwestern Canada From Teleseismic Body Wave Tomography[J],2020,125(2).
APA	Estève C.,Audet P.,Schaeffer A.J.,Schutt D.,Aster R.C.,&Cubley J..(2020).The Upper Mantle Structure of Northwestern Canada From Teleseismic Body Wave Tomography.Journal of Geophysical Research: Solid Earth,125(2).
MLA	Estève C.,et al."The Upper Mantle Structure of Northwestern Canada From Teleseismic Body Wave Tomography".Journal of Geophysical Research: Solid Earth 125.2(2020).