气候变化领域集成服务门户(CCPortal): Active crustal differentiation beneath the Rio Grande Rift

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DOI	10.1038/s41561-020-0640-z
	Active crustal differentiation beneath the Rio Grande Rift
	Cipar J.H.; Garber J.M.; Kylander-Clark A.R.C.; Smye A.J.
发表日期	2020
ISSN	17520894
起始页码	758
结束页码	763
卷号	13 期号:11
英文摘要	Silicon-rich continental crust is unique to Earth. Partial melting during high- to ultrahigh-temperature metamorphism (700 °C to >900 °C) promotes the long-term stability of this crust because it redistributes key elements between the crust and mantle and ultimately produces cooler, more-differentiated continents. Granulites—rocks formerly at high- to ultrahigh-temperature conditions—preserve a record of the stabilization of Earth’s continents, but the tectonic mechanisms that drive granulite formation are enigmatic. Here we present an analysis of lower-crustal xenoliths from the Rio Grande Rift—a nascent zone of extension in the southwestern United States. Uranium–lead geo- and thermochronology combined with thermobarometric modelling show that the lower 10 km of the crust currently resides at granulite-facies conditions, with the lowermost 2 km at ultrahigh-temperature conditions. Crust and mantle xenoliths define a continuous pressure-and-temperature array, indicating that a thin lithospheric mantle lid mediates elevated conductive heat transfer into the crust. These findings establish a direct link among ultrahigh-temperature metamorphism, collapse of the Laramide orogen and lithospheric mantle attenuation. Other indicators of modern ultrahigh-temperature metamorphism are consistent with these conditions prevailing over thousands of square kilometres across the US–Mexico Basin and Range province. Similarities between the pressure-and-temperature path from the Rio Grande lower crust and those from exhumed granulite terranes imply that post-thickening lithospheric extension is a primary mechanism to differentiate Earth’s continental crust. © 2020, The Author(s), under exclusive licence to Springer Nature Limited.
英文关键词	collapse structure; continental crust; differentiation; extensional tectonics; granulite; heat transfer; lower crust; partial melting; thermochronology; ultrahigh temperature metamorphism; xenolith; Mexico [North America]; Rio Grande Rift; United States; Valley of Mexico
语种	英语
来源期刊	Nature Geoscience
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/206759
作者单位	Department of Geosciences, The Pennsylvania State University, University Park, PA, United States; Department of Earth Science, University of California, Santa Barbara, CA, United States
推荐引用方式 GB/T 7714	Cipar J.H.,Garber J.M.,Kylander-Clark A.R.C.,et al. Active crustal differentiation beneath the Rio Grande Rift[J],2020,13(11).
APA	Cipar J.H.,Garber J.M.,Kylander-Clark A.R.C.,&Smye A.J..(2020).Active crustal differentiation beneath the Rio Grande Rift.Nature Geoscience,13(11).
MLA	Cipar J.H.,et al."Active crustal differentiation beneath the Rio Grande Rift".Nature Geoscience 13.11(2020).