气候变化领域集成服务门户(CCPortal): Basalts From the Chukchi Borderland: 40Ar/39Ar Ages and Geochemistry of Submarine Intraplate Lavas Dredged From the Western Arctic Ocean

CCPortal

DOI	10.1029/2019JB017604
	Basalts From the Chukchi Borderland: 40Ar/39Ar Ages and Geochemistry of Submarine Intraplate Lavas Dredged From the Western Arctic Ocean
	Mukasa S.B.; Andronikov A.; Brumley K.; Mayer L.A.; Armstrong A.
发表日期	2020
ISSN	21699313
卷号	125 期号:7
英文摘要	Submarine volcanism in the western Arctic Ocean, known as Amerasia Basin, is attributed to a mantle plume based on geophysics and meager geochemical evidence. Basaltic samples dredged from Chukchi Borderland within the basin have produced minimum 40Ar/39Ar ages for eruption at circa 118–112, circa 105–100, and circa 90–70 Ma, which we use to constrain tectonic models for basin opening. Major oxide and trace element concentrations and Sr, Nd, and Hf isotopic ratios of the lavas show that the circa 118–112 Ma samples from Northwind Ridge are tholeiites (low-Ti tholeiite I) with low degrees of rare-earth element (REE) fractionation, high overall heavy rare-earth element (HREE), and Mg# (Mg-number), which suggests magma derivation from a garnet-free source followed by minor crystal fractionation. Strontium, Nd, and Hf isotope systematics for these lavas and ratios of highly incompatible trace elements point toward a lithospheric source. Eruptions at circa 105–100 and circa 90–70 Ma, both at Healy Spur, produced two types of lavas: low-Ti tholeiite II—which are generally older than high-Ti tholeiite—both common in continental flood basalt (CFB) provinces and both with trace element abundance patterns typifying a garnet-free source and significant crystal fractionation for the high-Ti tholeiite. The isotope characteristics for both groups are common features of asthenospheric sources. Composition-time relationships for the lavas suggest inception of melting in the subcontinental lithospheric mantle (SCLM)—probably due to introduction of a heat source by a plume—followed later (at ca. 105–100 and ca. 90–70 Ma) by asthenospheric melting possibly triggered by plume rise. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Amerasia Basin; Arctic Ocean; Chukchi borderland; geochronology; isotope geochemistry; submarine volcanism
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/187765
作者单位	Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN, United States; Czech Geological Survey, Prague, Czech Republic; Fugro, Inc., Houston, TX, United States; Center for Coastal and Ocean Mapping/Joint Hydrographic Center, Jere A. Chase Ocean Engineering Laboratory, Durham, NH, United States
推荐引用方式 GB/T 7714	Mukasa S.B.,Andronikov A.,Brumley K.,et al. Basalts From the Chukchi Borderland: 40Ar/39Ar Ages and Geochemistry of Submarine Intraplate Lavas Dredged From the Western Arctic Ocean[J],2020,125(7).
APA	Mukasa S.B.,Andronikov A.,Brumley K.,Mayer L.A.,&Armstrong A..(2020).Basalts From the Chukchi Borderland: 40Ar/39Ar Ages and Geochemistry of Submarine Intraplate Lavas Dredged From the Western Arctic Ocean.Journal of Geophysical Research: Solid Earth,125(7).
MLA	Mukasa S.B.,et al."Basalts From the Chukchi Borderland: 40Ar/39Ar Ages and Geochemistry of Submarine Intraplate Lavas Dredged From the Western Arctic Ocean".Journal of Geophysical Research: Solid Earth 125.7(2020).