气候变化领域集成服务门户(CCPortal): Taconic suprasubduction zone magmatism in southern Laurentia: Evidence from the Dadeville Complex

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DOI	10.1130/B31885.1
	Taconic suprasubduction zone magmatism in southern Laurentia: Evidence from the Dadeville Complex
	Tull J.F.; Mueller P.A.; Farris D.W.; Davis B.L.
发表日期	2018
ISSN	167606
起始页码	1339
结束页码	1354
卷号	130 期号:2021-07-08
英文摘要	The record of the Taconic orogeny in the southern Appalachian orogen lacks clear evidence for many attributes of this classic Ordovician orogeny in the Northern Appalachians, including subduction of Laurentian lithosphere, the presence of Taconic allochthons and associated metamorphism and deformation, obduction of arc terranes, and accretion of Gondwanan terranes. Consequently, identifying a Taconic arc fragment in the southern Appalachian orogen, constraining its origin (e.g., peri-Laurentian or peri-Gondwana or intra-oceanic), and determining the polarity of subduction it represents are critical factors needed to evaluate the character of Taconic geodynamics throughout the Appalachians and Caledonides, including the location of the Taconic suture(s). In the southern Appalachian orogen, the Dadeville Complex is an amphibolite- facies allochthon with prominent mafic and ultramafic units in the Inner Piedmont of Alabama and Georgia. It has been proposed to be an accreted, peri-Gondwanan arc fragment obducted onto the Laurentian (or peri-Laurentian) margin. In contrast, we interpret 450-440 Ma U-Pb ages of zircons from Dadeville Complex meta-igneous rocks, Paleozoic and Precambrian detrital zircons from Dadeville Complex metasedimentary rocks, initial εNd values of igneous protoliths (basalt-trondhjemite-granite), initial εHf values of igneous and detrital zircons, and normalized trace-element abundances of mafic rocks to indicate that the Dadeville Complex likely formed in an Ordovician suprasubduction environment on Laurentian crust. This conclusion is compatible with recent interpretations of west-directed subduction as the concluding event of the northern Appalachian Taconic orogeny, but it suggests that the southern Laurentian margin was open throughout the period of the Taconic orogeny. © 2018 The Authors.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185011
作者单位	Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, United States; Department of Geological Sciences, University of Florida, Gainesville, FL 32611, United States; Department of Geology, Washington and Lee University, Lexington, VA 24450, United States
推荐引用方式 GB/T 7714	Tull J.F.,Mueller P.A.,Farris D.W.,et al. Taconic suprasubduction zone magmatism in southern Laurentia: Evidence from the Dadeville Complex[J],2018,130(2021-07-08).
APA	Tull J.F.,Mueller P.A.,Farris D.W.,&Davis B.L..(2018).Taconic suprasubduction zone magmatism in southern Laurentia: Evidence from the Dadeville Complex.Bulletin of the Geological Society of America,130(2021-07-08).
MLA	Tull J.F.,et al."Taconic suprasubduction zone magmatism in southern Laurentia: Evidence from the Dadeville Complex".Bulletin of the Geological Society of America 130.2021-07-08(2018).