气候变化领域集成服务门户(CCPortal): Provenance, U-Pb detrital zircon geochronology, Hf isotopic analyses, and Cr-spinel geochemistry of the northeast Yukon-Koyukuk Basin: Implications for interior basin development and sedimentation in Alaska

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DOI	10.1130/B31825.1
	Provenance, U-Pb detrital zircon geochronology, Hf isotopic analyses, and Cr-spinel geochemistry of the northeast Yukon-Koyukuk Basin: Implications for interior basin development and sedimentation in Alaska
	O'Brien T.M.; Miller E.L.; Pease V.; Hayden L.A.; Fisher C.M.; Hourigan J.K.; Vervoort J.D.
发表日期	2018
ISSN	167606
起始页码	825
结束页码	847
卷号	130 期号:2021-05-06
英文摘要	The Yukon-Koyukuk Basin is a large depression that covers ~118,000 km2 in western interior Alaska and is divided into two subbasins by a volcanic arc assemblage. Interpretations of the depositional setting of the northern Kobuk Koyukuk subbasin vary from a syncollisional forearc basin to a postorogenic successor basin formed by lithospheric extension. New results from sandstones and conglomerates collected from the Kobuk Koyukuk subbasin provide evidence for the timing of basin development, insight into the provenance of coarse siliciclastic sediments, and understanding of the nature of Cretaceous paleogeography and paleodrainage of Arctic Alaska. Early sedimentary rocks of the Kobuk Koyukuk subbasin contain abundant mafic to ultramafic volcanic and plutonic lithic fragments and mafic heavy minerals (e.g., spinel, clinopyroxene, and amphibole). They also contain abundant Middle Triassic to early Late Jurassic zircons (240-160 Ma; peak maximum ca. 200 Ma) that yield highly juvenile Hf isotopic compositions. Geochemistry of chromium spinels (Cr# = 0.17-0.86) suggests crystallization in an immature arc setting that likely developed over mid-ocean-ridge basalt-type crust. These early sediments originated from the mafic and ultramafic rocks of the Angayucham terrane, which was once much more extensive. These results suggest that the Angayucham terrane consists of an obducted Middle Triassic to early Late Jurassic oceanic arc complex that was coeval with oceanic- to continental-margin mafic arc magmatism in the Canadian Cordillera. Our generalized stratigraphy, along with U-Pb ages and Lu-Hf isotope analyses of zircons from sedimentary rocks of the Kobuk Koyukuk subbasin, reflects the tectonic and/ or erosional unroofing of the adjacent southern Brooks Range and Ruby terrane. U-Pb ages of detrital zircons collected from the stratigraphically lowest mafic- to ultramaficrich strata yield maximum depositional ages (107 Ma) that reflect initial erosion of the structurally highest Angayucham terrane and initiation of basin formation and deposition in the late Early Cretaceous. Continued uplift and erosion exposed structurally deeper metamorphic rocks, as revealed by incorporation of low-grade phyllites and eventually higher-grade metamorphic schistose lithic detritus and intermediate-composition (e.g., biotite) to metamorphic (e.g., chloritoid and xenotime) heavy mineral suites into the basin sediments. Differences in detrital zircon signatures between similar-age strata in the Colville foreland basin to the north of the Brooks Range and the Kobuk Koyukuk subbasin indicate that the sediments within the two basins were derived from two different sources, and the Brooks Range orogen acted as a drainage divide during late Early Cretaceous deposition. © 2017 Geological Society of America.
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/185030
作者单位	Department of Geological Sciences, Stanford University, Stanford, CA 94305, United States; Department of Geological Sciences, Stockholm University, Stockholm, SE-106 91, Sweden; U.S. Geological Survey, Menlo Park, CA 94025, United States; School of Earth and Environmental Sciences, Washington State University, Pullman, WA 99164, United States; Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA 95064, United States
推荐引用方式 GB/T 7714	O'Brien T.M.,Miller E.L.,Pease V.,et al. Provenance, U-Pb detrital zircon geochronology, Hf isotopic analyses, and Cr-spinel geochemistry of the northeast Yukon-Koyukuk Basin: Implications for interior basin development and sedimentation in Alaska[J],2018,130(2021-05-06).
APA	O'Brien T.M..,Miller E.L..,Pease V..,Hayden L.A..,Fisher C.M..,...&Vervoort J.D..(2018).Provenance, U-Pb detrital zircon geochronology, Hf isotopic analyses, and Cr-spinel geochemistry of the northeast Yukon-Koyukuk Basin: Implications for interior basin development and sedimentation in Alaska.Bulletin of the Geological Society of America,130(2021-05-06).
MLA	O'Brien T.M.,et al."Provenance, U-Pb detrital zircon geochronology, Hf isotopic analyses, and Cr-spinel geochemistry of the northeast Yukon-Koyukuk Basin: Implications for interior basin development and sedimentation in Alaska".Bulletin of the Geological Society of America 130.2021-05-06(2018).