干旱区生态环境知识资源中心(Arid): In search for the missing arc root of the Southern California Batholith: P-T-t evolution of upper mantle xenoliths of the Colorado Plateau Transition Zone

Arid

DOI	10.1016/j.epsl.2020.116447
	In search for the missing arc root of the Southern California Batholith: P-T-t evolution of upper mantle xenoliths of the Colorado Plateau Transition Zone
	Rautela, Ojashvi; Chapman, Alan D.; Shields, Jessie E.; Ducea, Mihai N.; Lee, Cin-Ty; Jiang, Hehe; Saleeby, Jason
通讯作者	Rautela, O
来源期刊	EARTH AND PLANETARY SCIENCE LETTERS
ISSN	0012-821X
EISSN	1385-013X
出版年	2020
卷号	547
英文摘要	Xenolith and seismic studies provide evidence for tectonic erosion and eastward displacement of lower crust-subcontinental mantle lithosphere (LC-SCML) underlying the Mojave Desert Region (i.e. southern California batholith (SCB)). Intensified traction associated with the Late Cretaceous flattening of the subducting Farallon plate, responsible for deforming the SW U.S., likely played a key role in bulldozing the tectonically eroded LC-SCML similar to 500 km eastwards, to underneath the Colorado Plateau Transition Zone (CPTZ) and further inboard. The garnet clinopyroxenite xenoliths from two CPTZ localities, Chino Valley and Camp Creek (central Arizona), provide a rare glimpse of the material underlying the CPTZ. Thermodynamic modeling, in addition to major and trace element thermobarometry, suggests that the xenoliths experienced peak conditions of equilibration at 600-900 degrees C and 12-28 lobar. These peak conditions, along with the composition of the xenoliths (type B garnet and diopsidic clinopyroxene) strongly suggest a continental arc residue (arclogite), rather than a lower plate subduction (eclogite), origin. A bimodal zircon U-Pb age distribution with peaks at ca. 75 and 150 Ma, and a Jurassic Sm-Nd garnet age (154 +/- 16 Ma, with initial sNd value of +8) overlaps eastern SCB pluton ages and suggests a consanguineous relationship. Cenozoic zircon U-Pb ages, REE geochemistry of zircon grains, and partially re-equilibrated Sm-Nd garnet ages indicate that displaced arclogite remained at elevated PT conditions (>700 degrees C) for lOs of Myr following its dispersal until late Oligocene entrainment in host latite. With a similar to 100 Myr long thermal history overlapping that of the SCB and the CPTZ, these assemblages also contain evidence for late-stage hydration (e.g. secondary amphibole), potentially driven by de-watering of the Laramide slab. In light of these results, we suggest that the CPTZ arclogite originates from beneath the eastern half of the SCB, where it began forming in Late Jurassic time as mafic keel to continental arc magmas. The displacement and re-affixation of the arclogites further inboard during the Late Cretaceous flat slab subduction, might have contributed to the tectonic stability of the Colorado Plateau relative to adjacent geologic provinces through Laramide time and likely preconditioned the region to Cenozoic tectonism, e.g. present-day delamination beneath the plateau, high-magnitude extension and formation of metamorphic core complexes. (C) 2020 Elsevier B.V. All rights reserved.
英文关键词	Laramide Colorado Plateau Transition Zone Southern California Batholith Cordilleran tectonics garnet-clinopyroxenite P-T-t evolution
类型	Article
语种	英语
开放获取类型	Bronze
收录类别	SCI-E
WOS记录号	WOS:000557762500010
WOS关键词	WESTERN UNITED-STATES ; SIERRA-NEVADA ; LITHOSPHERIC MANTLE ; CRUSTAL STRUCTURE ; LARAMIDE OROGENY ; CENTRAL ARIZONA ; MOJAVE DESERT ; GARNET ; DELAMINATION ; SUBDUCTION
WOS类目	Geochemistry & Geophysics
WOS研究方向	Geochemistry & Geophysics
来源机构	University of Arizona
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/325527
作者单位	[Rautela, Ojashvi; Chapman, Alan D.] Macalester Coll, Geol Dept, St Paul, MN 55105 USA; [Shields, Jessie E.] Calif State Univ Fresno, Dept Earth & Environm Sci, Fresno, CA 93740 USA; [Ducea, Mihai N.] Univ Arizona, Dept Geosci, Tucson, AZ 85721 USA; [Ducea, Mihai N.] Univ Bucharest, Fac Geol & Geophys, Bucharest 010041, Romania; [Lee, Cin-Ty; Jiang, Hehe] Rice Univ, Dept Earth Sci, Houston, TX 77005 USA; [Saleeby, Jason] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA
推荐引用方式 GB/T 7714	Rautela, Ojashvi,Chapman, Alan D.,Shields, Jessie E.,et al. In search for the missing arc root of the Southern California Batholith: P-T-t evolution of upper mantle xenoliths of the Colorado Plateau Transition Zone[J]. University of Arizona,2020,547.
APA	Rautela, Ojashvi.,Chapman, Alan D..,Shields, Jessie E..,Ducea, Mihai N..,Lee, Cin-Ty.,...&Saleeby, Jason.(2020).In search for the missing arc root of the Southern California Batholith: P-T-t evolution of upper mantle xenoliths of the Colorado Plateau Transition Zone.EARTH AND PLANETARY SCIENCE LETTERS,547.
MLA	Rautela, Ojashvi,et al."In search for the missing arc root of the Southern California Batholith: P-T-t evolution of upper mantle xenoliths of the Colorado Plateau Transition Zone".EARTH AND PLANETARY SCIENCE LETTERS 547(2020).