Sr-Nd-Hf Isotopic Analysis of <10 mg Dust Samples: Implications for Ice Core Dust Source Fingerprinting

Gábor Újvári, Wencke Wegner, Urs Klötzli, Monika Horschinegg, Dorothee Hippler

Publikation: Beitrag in einer FachzeitschriftArtikelForschungBegutachtung

Abstract

Combined Sr-Nd-Hf isotopic data of two reference materials (AGV-1/BCR2) and 50, 10, and 5 mg aliquots of carbonate-free fine grain (<10 μm) separates of three loess samples (Central Europe/NUS, China/BEI, USA/JUD) are presented. Good agreement between measured and reference Sr-Nd-Hf isotopic compositions (ICs) demonstrate that robust isotopic ratios can be obtained from 5 to 10 mg size rock samples using the ion exchange/mass spectrometry techniques applied. While 87Sr/86Sr ratios of dust aluminosilicate fractions are affected by even small changes in pretreatments, Nd isotopic ratios are found to be insensitive to acid leaching, grain-size or weathering effects. However, the Nd isotopic tracer is sometimes inconclusive in dust source fingerprinting (BEI and NUS both close to ɛNd(0) –10). Hafnium isotopic values (<10 μm fractions) are homogenous for NUS, while highly variable for BEI. This heterogeneity and vertical arrays of Hf isotopic data suggest zircon depletion effects toward the clay fractions (<2 μm). Monte Carlo simulations demonstrate that the Hf IC of the dust <10 μm fraction is influenced by both the abundance of zircons present and maturity of crustal rocks supplying this heavy mineral, while the <2 μm fraction is almost unaffected. Thus, ɛHf(0) variations in the clay fraction are largely controlled by the Hf IC of clays/heavy minerals having high Lu/Hf and radiogenic 176Hf/177Hf IC. Future work should be focused on Hf IC of both the <10 and <2 μm fractions of dust from potential source areas to gain more insight into the origin of last glacial dust in Greenland ice cores.

Originalspracheenglisch
Seiten (von - bis)60-72
Seitenumfang13
FachzeitschriftGeochemistry, Geophysics, Geosystems
Jahrgang19
Ausgabenummer1
DOIs
PublikationsstatusVeröffentlicht - 1 Jan 2018

Fingerprint

Powder magnetic cores
isotopic analysis
isotope ratios
Ice
ice core
Dust
ice
isotopic composition
dust
Chemical analysis
heavy mineral
isotopic ratio
clays
Minerals
zircon
Hafnium
Rocks
hafnium
clay
Carbonates

Schlagwörter

    ASJC Scopus subject areas

    • Geophysik
    • !!Geochemistry and Petrology

    Dies zitieren

    Sr-Nd-Hf Isotopic Analysis of <10 mg Dust Samples : Implications for Ice Core Dust Source Fingerprinting. / Újvári, Gábor; Wegner, Wencke; Klötzli, Urs; Horschinegg, Monika; Hippler, Dorothee.

    in: Geochemistry, Geophysics, Geosystems, Jahrgang 19, Nr. 1, 01.01.2018, S. 60-72.

    Publikation: Beitrag in einer FachzeitschriftArtikelForschungBegutachtung

    Újvári, Gábor ; Wegner, Wencke ; Klötzli, Urs ; Horschinegg, Monika ; Hippler, Dorothee. / Sr-Nd-Hf Isotopic Analysis of <10 mg Dust Samples : Implications for Ice Core Dust Source Fingerprinting. in: Geochemistry, Geophysics, Geosystems. 2018 ; Jahrgang 19, Nr. 1. S. 60-72.
    @article{24db411a6e0344d4803db68e689d9cda,
    title = "Sr-Nd-Hf Isotopic Analysis of <10 mg Dust Samples: Implications for Ice Core Dust Source Fingerprinting",
    abstract = "Combined Sr-Nd-Hf isotopic data of two reference materials (AGV-1/BCR2) and 50, 10, and 5 mg aliquots of carbonate-free fine grain (<10 μm) separates of three loess samples (Central Europe/NUS, China/BEI, USA/JUD) are presented. Good agreement between measured and reference Sr-Nd-Hf isotopic compositions (ICs) demonstrate that robust isotopic ratios can be obtained from 5 to 10 mg size rock samples using the ion exchange/mass spectrometry techniques applied. While 87Sr/86Sr ratios of dust aluminosilicate fractions are affected by even small changes in pretreatments, Nd isotopic ratios are found to be insensitive to acid leaching, grain-size or weathering effects. However, the Nd isotopic tracer is sometimes inconclusive in dust source fingerprinting (BEI and NUS both close to ɛNd(0) –10). Hafnium isotopic values (<10 μm fractions) are homogenous for NUS, while highly variable for BEI. This heterogeneity and vertical arrays of Hf isotopic data suggest zircon depletion effects toward the clay fractions (<2 μm). Monte Carlo simulations demonstrate that the Hf IC of the dust <10 μm fraction is influenced by both the abundance of zircons present and maturity of crustal rocks supplying this heavy mineral, while the <2 μm fraction is almost unaffected. Thus, ɛHf(0) variations in the clay fraction are largely controlled by the Hf IC of clays/heavy minerals having high Lu/Hf and radiogenic 176Hf/177Hf IC. Future work should be focused on Hf IC of both the <10 and <2 μm fractions of dust from potential source areas to gain more insight into the origin of last glacial dust in Greenland ice cores.",
    keywords = "dust, ice core, provenance, Sr-Nd-Hf isotopes, trace elements",
    author = "G{\'a}bor {\'U}jv{\'a}ri and Wencke Wegner and Urs Kl{\"o}tzli and Monika Horschinegg and Dorothee Hippler",
    year = "2018",
    month = "1",
    day = "1",
    doi = "10.1002/2017GC007136",
    language = "English",
    volume = "19",
    pages = "60--72",
    journal = "Geochemistry, Geophysics, Geosystems",
    issn = "1525-2027",
    publisher = "Wiley",
    number = "1",

    }

    TY - JOUR

    T1 - Sr-Nd-Hf Isotopic Analysis of <10 mg Dust Samples

    T2 - Implications for Ice Core Dust Source Fingerprinting

    AU - Újvári, Gábor

    AU - Wegner, Wencke

    AU - Klötzli, Urs

    AU - Horschinegg, Monika

    AU - Hippler, Dorothee

    PY - 2018/1/1

    Y1 - 2018/1/1

    N2 - Combined Sr-Nd-Hf isotopic data of two reference materials (AGV-1/BCR2) and 50, 10, and 5 mg aliquots of carbonate-free fine grain (<10 μm) separates of three loess samples (Central Europe/NUS, China/BEI, USA/JUD) are presented. Good agreement between measured and reference Sr-Nd-Hf isotopic compositions (ICs) demonstrate that robust isotopic ratios can be obtained from 5 to 10 mg size rock samples using the ion exchange/mass spectrometry techniques applied. While 87Sr/86Sr ratios of dust aluminosilicate fractions are affected by even small changes in pretreatments, Nd isotopic ratios are found to be insensitive to acid leaching, grain-size or weathering effects. However, the Nd isotopic tracer is sometimes inconclusive in dust source fingerprinting (BEI and NUS both close to ɛNd(0) –10). Hafnium isotopic values (<10 μm fractions) are homogenous for NUS, while highly variable for BEI. This heterogeneity and vertical arrays of Hf isotopic data suggest zircon depletion effects toward the clay fractions (<2 μm). Monte Carlo simulations demonstrate that the Hf IC of the dust <10 μm fraction is influenced by both the abundance of zircons present and maturity of crustal rocks supplying this heavy mineral, while the <2 μm fraction is almost unaffected. Thus, ɛHf(0) variations in the clay fraction are largely controlled by the Hf IC of clays/heavy minerals having high Lu/Hf and radiogenic 176Hf/177Hf IC. Future work should be focused on Hf IC of both the <10 and <2 μm fractions of dust from potential source areas to gain more insight into the origin of last glacial dust in Greenland ice cores.

    AB - Combined Sr-Nd-Hf isotopic data of two reference materials (AGV-1/BCR2) and 50, 10, and 5 mg aliquots of carbonate-free fine grain (<10 μm) separates of three loess samples (Central Europe/NUS, China/BEI, USA/JUD) are presented. Good agreement between measured and reference Sr-Nd-Hf isotopic compositions (ICs) demonstrate that robust isotopic ratios can be obtained from 5 to 10 mg size rock samples using the ion exchange/mass spectrometry techniques applied. While 87Sr/86Sr ratios of dust aluminosilicate fractions are affected by even small changes in pretreatments, Nd isotopic ratios are found to be insensitive to acid leaching, grain-size or weathering effects. However, the Nd isotopic tracer is sometimes inconclusive in dust source fingerprinting (BEI and NUS both close to ɛNd(0) –10). Hafnium isotopic values (<10 μm fractions) are homogenous for NUS, while highly variable for BEI. This heterogeneity and vertical arrays of Hf isotopic data suggest zircon depletion effects toward the clay fractions (<2 μm). Monte Carlo simulations demonstrate that the Hf IC of the dust <10 μm fraction is influenced by both the abundance of zircons present and maturity of crustal rocks supplying this heavy mineral, while the <2 μm fraction is almost unaffected. Thus, ɛHf(0) variations in the clay fraction are largely controlled by the Hf IC of clays/heavy minerals having high Lu/Hf and radiogenic 176Hf/177Hf IC. Future work should be focused on Hf IC of both the <10 and <2 μm fractions of dust from potential source areas to gain more insight into the origin of last glacial dust in Greenland ice cores.

    KW - dust

    KW - ice core

    KW - provenance

    KW - Sr-Nd-Hf isotopes

    KW - trace elements

    UR - http://www.scopus.com/inward/record.url?scp=85040658519&partnerID=8YFLogxK

    U2 - 10.1002/2017GC007136

    DO - 10.1002/2017GC007136

    M3 - Article

    VL - 19

    SP - 60

    EP - 72

    JO - Geochemistry, Geophysics, Geosystems

    JF - Geochemistry, Geophysics, Geosystems

    SN - 1525-2027

    IS - 1

    ER -