An integrated study of the eolian dust in pelagic sediments from the North Pacific Ocean based on environmental magnetism, transmission electron microscopy, and diffuse reflectance spectroscopy

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doi: 10.1002/2017JB014951
Author(s): Zhang Qiang; Liu Qingsong; Li Jinhua; Sun Youbin
Author Affiliation(s): Primary:
University of Chinese Academy of Sciences, College of Earth and Planetary Sciences, Beijing, China
Southern University of Science and Technology, China
Chinese Academy of Sciences, Institute of Geology and Geophysics, China
Chinese Academy of Sciences, Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, China
Volume Title: Journal of Geophysical Research: Solid Earth
Source: Journal of Geophysical Research: Solid Earth, 123(5), p.3358-3376. Publisher: Wiley-Blackwell for American Geophysical Union, Washington, DC, United States. ISSN: 2169-9313
Note: In English. 124 refs.; illus., incl. 1 table, sketch map
Summary: Eolian dust is a major terrigenous component in North Pacific Ocean pelagic sediments and is an important recorder of Asian terrestrial environmental evolution and Northern Hemisphere atmospheric circulation. In order to extract and quantify wind-borne mineral signals and develop a reliable eolian dust proxy for pelagic sediments, we investigated sediments from Ocean Drilling Program Hole 885A, North Pacific Ocean, by integrating results from environmental magnetism, transmission electron microscopy, and diffuse reflectance spectroscopy (DRS). Our results indicate that ferrimagnetic and antiferromagnetic minerals coexist in the sediments. The former includes biogenic magnetite, nano-sized single domain (titano) magnetite inclusions embedded in silicate hosts, submicron vortex state magnetite, and ultrafine superparamagnetic maghemite. The latter includes hematite and goethite. Our results indicate that magnetic properties can be used to determine an overall trend of increased eolian dust inputs, with additional significant influence from biogenic and volcanogenic components. In contrast, a newly proposed parameter RelHm+Gt (combined hematite and goethite concentration) obtained from DRS measurements extracts precisely the eolian signal and precludes other components. Our DRS results indicate that hematite/goethite and siliceous fractions deposited at Hole 885A were jointly delivered to the North Pacific Ocean from Asian dust sources. Therefore, we suggest that RelHm+Gt is a reliable eolian dust proxy for pelagic sediments in this region. Abstract Copyright (2018), American Geophysical Union. All Rights Reserved.
Year of Publication: 2018
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Anhysteretic remanent magnetization; Arid environment; Asia; Atmospheric circulation; Bivariate analysis; Brunhes Chron; Cenozoic; China; Clastic sediments; Coercivity; Corrections; Demagnetization; Deposition; Dust; EDS spectra; Electron microscopy data; Equations; Far East; Frequency; Gauss Chron; Gilbert Chron; Goethite; Grain size; Hematite; Hysteresis; Isothermal remanent magnetization; Jaramillo Subchron; Leg 145; Lower Pleistocene; Maghemite; Magnetic minerals; Magnetic properties; Magnetic susceptibility; Magnetite; Magnetization; Marine sediments; Matuyama Chron; Measurement; Neogene; North Pacific; Northwestern China; ODP Site 885; Ocean Drilling Program; Olduvai Subchron; Oxides; Pacific Ocean; Paleoatmosphere; Paleoenvironment; Paleomagnetism; Pelagic environment; Pleistocene; Pliocene; Provenance; Qaidam Basin; Quantitative analysis; Quaternary; Reflectance; Remanent magnetization; Reversals; Saturation magnetization; Sediment transport; Sediments; Semi-arid environment; Siliceous composition; Spatial distribution; Spectra; Statistical analysis; TEM data; Temperature; Terrestrial environment; Tertiary; Tibetan Plateau; Transport; Upper Quaternary; Variations; Volcanism; Wind transport; X-ray spectra
Coordinates: N444118 N444118 W1681619 W1681619
Record ID: 2019049421
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom