气候变化领域集成服务门户(CCPortal): Petrogenesis of Basaltic Lavas From the West Pacific Seamount Province: Geochemical and Sr-Nd-Pb-Hf Isotopic Constraints

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DOI	10.1029/2020JB021598
	Petrogenesis of Basaltic Lavas From the West Pacific Seamount Province: Geochemical and Sr-Nd-Pb-Hf Isotopic Constraints
	Yan Q.; Milan L.; Saunders J.E.; Shi X.
发表日期	2021
ISSN	21699313
卷号	126 期号:5
英文摘要	In this study, we report new major and trace element, Sr-Nd-Pb-Hf isotopic compositions and Ar-Ar ages for basaltic lavas from seven poorly studied seamounts/guyots in the Western Pacific Seamount Province (WPSP). A review of new and published Ar-Ar ages for seamounts/guyots confirm no linear age progression, as would be expected if these seamounts were produced by the Pacific Plate moving over a stationary mantle plume. These samples exhibit an alkalic character and can be produced by small-degree partial melting of garnet pyroxenite with CO2. Their isotopic data identify four mantle end-members (DMM, EMI, EMII, and HIMU) in the WPSP source region. These results confirm previous studies that invoke multiple contemporaneous plumelets in the region and a heterogeneous upper mantle reservoir which has been overprinted by multiple discrete hotspots, which create an anomalous and heterogeneous upper mantle because of mixing/overlapping EMI, EMII, and HIMU tracks, and age progressive volcanism is totally obscured. We propose a model where relict fragments of enriched mantle with distinct isotopic compositions residing in the upper mantle were a product of the formation of the adjacent large oceanic plateaus. These events introduce heterogeneity in the depleted mantle. The infiltration and metasomatism of these relict enriched components by carbonatitic fluids from the low-velocity zone, create a source that then underwent small degrees of decompressional melting. The partial melts exploited pre-existing lithospheric faults as an upwelling conduit and the resultant seafloor lava flows have obscured evidence to those pre-existing lithospheric faults. © 2021. American Geophysical Union. All Rights Reserved.
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/187100
作者单位	Key Laboratory of Marine Geology and Metallogeny, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; Division of Earth Sciences, School of Environmental and Rural Science, University of New England, Armidale, NSW, Australia
推荐引用方式 GB/T 7714	Yan Q.,Milan L.,Saunders J.E.,et al. Petrogenesis of Basaltic Lavas From the West Pacific Seamount Province: Geochemical and Sr-Nd-Pb-Hf Isotopic Constraints[J],2021,126(5).
APA	Yan Q.,Milan L.,Saunders J.E.,&Shi X..(2021).Petrogenesis of Basaltic Lavas From the West Pacific Seamount Province: Geochemical and Sr-Nd-Pb-Hf Isotopic Constraints.Journal of Geophysical Research: Solid Earth,126(5).
MLA	Yan Q.,et al."Petrogenesis of Basaltic Lavas From the West Pacific Seamount Province: Geochemical and Sr-Nd-Pb-Hf Isotopic Constraints".Journal of Geophysical Research: Solid Earth 126.5(2021).