Hafnium (and Sr-Nd) isotope analysis of mineral dust: from sample digestions to mass spectrometry

2020 ◽  
Author(s):  
Gabor Ujvari ◽  
Urs Klötzli ◽  
Monika Horschinegg ◽  
Wencke Wegner ◽  
Dorothee Hippler ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mineral Dust ◽  
Ice Cores ◽  
Isotope Ratios ◽  
Hf Isotope ◽  
Development Fund ◽  
Nd Isotope ◽  
Isotopic Compositions ◽  
Isotopic Analyses ◽  
Isotope Analyses

<p>Mineral dust in ice cores provides insight into past atmospheric circulation patterns provided that the source(s) of these aerosols can be identified. Isotopes of strontium, neodymium and lead are frequently used for source discrimination in ice cores, while those of hafnium much less so. This is because of the extremely low (1-5 ng) amounts of Hf present in 5-10 mg dust samples usually available for isotopic analyses from the dustiest periods of past glaciations, e.g. the Last Glacial Maximum. The use of <sup>176</sup>Hf/<sup>177</sup>Hf isotopic ratios in dust fingerprinting is crucial in situations when Sr-Nd isotopes are inconclusive in source identification.</p><p>The overall Hf budget is dominated by the heavy mineral zircon in silt-sized, wind-blown material, while it is significantly depleted in the finer (<5 µm) fractions and the effects of other minerals (apatite, sphene, monazite, xenotime and clay minerals) become increasingly important. Since the major hosts of Hf are refractory heavy minerals, the complete digestion of dust material is crucial in determining reliable Hf isotope ratios.</p><p>Here we introduce a closed vessel ammonium bifluoride (NH<sub>4</sub>HF<sub>2</sub>) digestion method (220 °C), which is a fast and low blank (0.5 ng for Sr, 0.2 ng for Nd, and <25 pg for Hf) technique for dust dissolution, prior to column chemistry for combined Hf-Sr-Nd isotope analyses. Repeated measurements of the Hf isotope ratios of USGS geological reference materials (AGV-2, BCR-2 and GSP-2) demonstrate that raw, non fractionation corrected <sup>176</sup>Hf/<sup>177</sup>Hf ratios are accurate within 5-50 ppm, while the JMC-475 fractionation corrected values are accurate to 5-10 ppm, compared to reference values using our ion exchange chemistry setup. This methodology also allows separating Sr and Nd from the same samples, and analysing the <sup>87</sup>Sr/<sup>86</sup>Sr and <sup>143</sup>Nd/<sup>144</sup>Nd isotopic compositions. Here we discuss mass spectrometry issues (including sensitivity) of TIMS and two different MC-ICP-MS instruments, and major limitations on dust sample size for Hf-Sr-Nd isotope analyses. Furthermore, the mineralogical background of Hf isotopic compositions, including zircon depletion effects and clay mineralogy (illite) control will be demonstrated. Hf isotope data obtained from four NorthGRIP ice core samples will be presented.</p><p>This study was financially supported by the FWF Austria through a Lise Meitner grant (project nr. M 2503-N29) and the European Regional Development Fund in the project of GINOP-2.3.2.-15-2016-00009 ‘ICER’.</p>

scholarly journals U–Pb and Hf isotopic analyses of detrital zircons from the Taku terrane, southeast Alaska

2016 ◽  
Vol 53 (10) ◽  
pp. 979-992 ◽  
Author(s):  
Dominique Giesler ◽  
George Gehrels ◽  
Mark Pecha ◽  
Chelsi White ◽  
Intan Yokelson ◽  
...  
Keyword(s):  
Volcanic Rocks ◽  
Detrital Zircons ◽  
Hf Isotope ◽  
Igneous Rocks ◽  
Upper Permian ◽  
Lower Permian ◽  
Coast Mountains ◽  
Isotopic Analyses ◽  
Gravina Belt ◽  
Isotope Analyses

The Taku terrane consists of metamorphosed Carboniferous through Triassic marine clastic strata, volcanic rocks, and limestone that occur along the western margin of the Coast Mountains in southeastern Alaska. These rocks are juxtaposed along mid-Cretaceous thrust faults over Jura-Cretaceous basinal strata of the Gravina belt to the west and beneath Proterozoic through Carboniferous metamorphic rocks of the Yukon–Tanana terrane to the east. This paper presents U–Pb ages and Hf isotope analyses of detrital zircons from the Taku terrane, and compares these values with information from the adjacent Wrangellia, Alexander, and northern and southern portions of the Yukon–Tanana terrane (YTTn and YTTs). These comparisons suggest that (i) Carboniferous strata of the Taku terrane were shed mainly from mid-Paleozoic igneous rocks of YTTs, (ii) Permian strata of the Taku terrane were shed from mid-Paleozoic igneous rocks and intraformational Lower Permian volcanic rocks of YTTs as well as Upper Permian volcanic rocks exposed in YTTn, and (iii) Triassic sandstones were shed from mid-Paleozoic igneous rocks of YTTs, whereas conglomerates were shed mainly from mid-Paleozoic arc rocks in YTTn. Hf isotope analyses of Paleozoic zircons record increasing continental input during Silurian–Devonian and Permian phases of magmatism. Similarities in isotopic characteristics, combined with stratigraphic and geochemical information presented by previous workers, suggest that strata of the Taku terrane accumulated on (and partly as lateral equivalents of) rocks of YTTs, and that the combined assemblages formed outboard or along strike of YTTn.

scholarly journals Ultra-high-precision Nd-isotope measurements of geological materials by MC-ICPMS

2016 ◽  
Vol 31 (7) ◽  
pp. 1490-1504 ◽  
Author(s):  
Nikitha Susan Saji ◽  
Daniel Wielandt ◽  
Chad Paton ◽  
Martin Bizzarro
Keyword(s):  
Mass Spectrometry ◽  
High Precision ◽  
Inductively Coupled Plasma ◽  
Isotope Ratios ◽  
Nd Isotope ◽  
Geological Materials ◽  
Inductively Coupled ◽  
Accuracy And Precision ◽  
Plasma Mass Spectrometry ◽  
Isotope Measurements

We report novel techniques allowing the measurement of Nd-isotope ratios with unprecedented accuracy and precision by multi-collector inductively coupled plasma mass spectrometry.

A secondary ion mass spectrometry (SIMS) re-evaluation of B and Li isotopic compositions of Cu-bearing elbaite from three global localities

2011 ◽  
Vol 75 (4) ◽  
pp. 2485-2494 ◽  
Author(s):  
T. Ludwig ◽  
H. R. Marschall ◽  
P. A. E. Pogge von Strandmann ◽  
B. M. Shabaga ◽  
M. Fayek ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Trace Element ◽  
Secondary Ion Mass Spectrometry ◽  
Isotopic Compositions ◽  
Ion Mass Spectrometry ◽  
Secondary Ion ◽  
Isotope Analyses

AbstractCu-bearing elbaite from Paraíba (Brazil) is a highly-prized gem tourmaline. Specimens of similar quality from localities in Mozambique and Nigeria are being sold, and reliable provenance tools are required to distinguish specimens from the original locality from ‘Paraíba-type’ tourmaline from Africa. Here we present Li and B isotope analyses of Cu-bearing elbaite from all three localities and demonstrate the suitability of these isotope systems as a provenance tool. Isotopic profiles across chemically zoned grains revealed homogenous B and Li isotopic compositions, demonstrating a strong advantage of their application as a provenance tool as opposed to major, minor or trace element signatures.Li and B isotopes of all investigated samples of Cu-bearing elbaites from the three localities are within the range of previously published granitic and pegmatitic tourmaline. Anomalous isotope compositions published previously for these samples are corrected by our results.

Plagioclase weathering by mycorrhizal plants in a Ca-depleted catchment, inferred from Nd isotope ratios and REE composition

2017 ◽  
Vol 51 (6) ◽  
pp. 537-550
Author(s):  
Tasuku Akagi ◽  
Tomohiro Miura ◽  
Rie Takada ◽  
Kazuo Watanabe
Keyword(s):  
Isotope Ratios ◽  
Nd Isotope ◽  
Mycorrhizal Plants

In situ Fe isotopic analyses of fourteen reference materials using a synthetic Cr standard for mass bias and isobaric interference corrections by femtosecond LA-MC-ICP-MS

2021 ◽  
Author(s):  
Lei Xu ◽  
Wen Zhang ◽  
Tao Luo ◽  
Jin-Hui Yang ◽  
Zhaochu Hu
Keyword(s):  
Reference Materials ◽  
Isotope Ratios ◽  
Isobaric Interference ◽  
Analytical Technique ◽  
Mass Bias ◽  
Icp Ms ◽  
Isotopic Analyses

High precise and accurate measurements of Fe isotope ratios for fourteen reference materials from the USGS, MPI-DING and CGSG were successfully carried out using a developed analytical technique by fs...

New approaches to crustal evolution studies and the origin of granitic rocks: what can the Lu-Hf and Re-Os isotope systems tell us?

1996 ◽  
Vol 87 (1-2) ◽  
pp. 339-352 ◽  
Author(s):  
Clark M. Johnson ◽  
Steven B. Shirey ◽  
Karin M. Barovich
Keyword(s):  
Continental Crust ◽  
Isotope Ratios ◽  
Granitic Rocks ◽  
Nd Isotope ◽  
Volcanic Arcs ◽  
Depleted Mantle ◽  
Os Isotopes ◽  
Isotope System ◽  
Os Isotope

ABSTRACT:The Lu-Hf and Re-Os isotope systems have been applied sparsely to elucidate the origin of granites, intracrustal processes and the evolution of the continental crust. The presence or absence of garnet as a residual phase during partial melting will strongly influence Lu/Hf partitioning, making the Lu–Hf isotope system exceptionally sensitive to evaluating the role of garnet during intracrustal differentiation processes. Mid-Proterozoic (1·1–1·5Ga ) ‘anorogenic’ granites from the western U.S.A. appear to have anomalously high εHf values, relative to their εNd values, compared with Precambrian orogenic granites from several continents. The Hf-Nd isotope variations for Precambrian orogenic granites are well explained by melting processes that are ultimately tied to garnet-bearing sources in the mantle or crust. Residual, garnet-bearing lower and middle crust will evolve to anomalously high εHf values over time and may be the most likely source for later ‘anorogenic’ magmas. When crustal and mantle rocks are viewed together in terms of Hf and Nd isotope compositions, a remarkable mass balance is apparent for at least the outer silicate earth where Precambrian orogenic continental crust is the balance to the high-εHf depleted mantle, and enriched lithospheric mantle is the balance to the low-εHf depleted mantle.Although the continental crust has been envisioned to have exceptionally high Re/Os ratios and very radiogenic Os isotope compositions, new data obtained on magnetite mineral separates suggest that some parts of the Precambrian continental crust are relatively Os-rich and non-radiogenic. It remains unclear how continental crust may obtain non-radiogenic Os isotope ratios, and these results have important implications for Re-Os isotope evolution models. In contrast, Phanerozoic batholiths and volcanic arcs that are built on young mafic lower crust may have exceptionally radiogenic Os isotope ratios. These results highlight the unique ability of Os isotopes to identify young mafic crustal components in orogenic magmas that are essentially undetectable using other isotope systems such as O, Sr, Nd and Pb.

Stable isotopes in planktonic and benthic foraminifera from Arctic Ocean surface sediments

1988 ◽  
Vol 25 (5) ◽  
pp. 701-709 ◽  
Author(s):  
A. E. Aksu ◽  
G. Vilks
Keyword(s):  
Surface Water ◽  
Arctic Ocean ◽  
Sea Water ◽  
Ocean Surface ◽  
The Arctic ◽  
Size Fractions ◽  
Isotopic Compositions ◽  
Isotopic Analyses ◽  
Stable Isotopic ◽  
Surface Water Salinity

Oxygen and carbon isotopic analyses have been performed on the tests of Planulina wuellerstorfi and three size fractions of sinistral Neogloboquadrina pachyderma recovered from 33 Arctic Ocean surface-sediment samples. Stable isotopic compositions of N. pachyderma are found to be dependent on the test size: larger specimens show considerable enrichment in both δ18O and δ18C. The difference between the isotopic compositions of the 63–125 and 125–250 μm size fractions in N. pachyderma can be explained by biogenic fractionation effects during foraminiferal test growth. Larger (250–500 μm) N. pachyderma displayed accretions of secondary calcite, i.e., the outermost shell contained significant amounts of inorganically precipitated magnesium calcite. Thus, larger foraminifera may not be suited for down-core stable isotopic studies. There is a difference of ~2‰ between δ18O values of surface samples from the eastern and western Arctic Ocean, reflecting large differences between surface-water salinity in these regions. Therefore, oxygen isotopic data may have limited use as a chronostratigraphic tool in down-core studies in the Arctic Ocean, but we can use them to infer past variations in surface-water salinities. Planulina wuellerstorfi also showed depletions of both δ18O and δ18C in its calcite tests relative to calcite precipitated in isotopic equilibrium with ambient sea water; these depletions ranged from −0.8 to −0.9‰ in δ18Oand −1.2 to −0.9‰ in δ18C. This taxon is found to deposit its shell very close to the δ18C of ΣCO2 of bottom waters.

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