scholarly journals Calibrated cryo-cell UV-LA-ICPMS elemental concentrations from NGRIP ice core reveal abrupt, sub-annual variability in dust across the interstadial period GI-21.2

2016 ◽  
Author(s):  
Damiano Della Lunga ◽  
Wolfgang Müller ◽  
Sune Olander Rasmussen ◽  
Anders Svensson ◽  
Paul Vallelonga

Abstract. Several abrupt shifts from periods of extreme cold (Greenland stadials, GS) to relatively warmer conditions (Greenland interstadials, GI) called Dansgaard-Oeschger events are recorded in the Greenland ice cores. Using cryo-cell UV-laser-ablation inductively-coupled-plasma mass spectrometry (UV-LA-ICPMS), we analysed a 2.85 m NGRIP ice core section (~ 250 years; 2691.50–2688.65 m depth) across the transitions of GI-21.2, a short-lived interstadial prior to interstadial GI-21.1 (GI-21.2: 84.87–85.09 ka b2k). GI-21.2 is a ~ 100-year-long period with δ18O values 3–4 ‰ higher than the following ~ 200 years of stadial conditions (GS-21.2), which precede the major GI-21.1 warming. We report concentrations of "major" elements indicative of dust and/or sea salt (Na, Fe, Al, Ca, Mg) at a spatial resolution of ~ 200 μm, while maintaining detection limits in the low-ppb range, thereby achieving sub-annual time resolution even in deep NGRIP ice. We present an improved external calibration and quantification procedure using a set of five ice standards made from aqueous (international) standard solutions. Our results show that element concentrations decrease drastically (more than tenfold) at the warming onset of GI-21.2 at the scale of a single year, followed by relatively low concentrations characterizing the interstadial part before gradually reaching again typical stadial values.

2017 ◽  
Vol 11 (3) ◽  
pp. 1297-1309 ◽  
Author(s):  
Damiano Della Lunga ◽  
Wolfgang Müller ◽  
Sune Olander Rasmussen ◽  
Anders Svensson ◽  
Paul Vallelonga

Abstract. Several abrupt shifts from periods of extreme cold (Greenland stadials, GS) to relatively warmer conditions (Greenland interstadials, GI) called Dansgaard–Oeschger events are recorded in the Greenland ice cores. Using cryo-cell UV-laser-ablation inductively coupled-plasma mass spectrometry (UV-LA-ICPMS), we analysed a 2.85 m NGRIP ice core section (2691.50–2688.65 m depth, age interval 84.86–85.09 ka b2k, thus covering  ∼  230 years) across the transitions of GI-21.2, a short-lived interstadial prior to interstadial GI-21.1. GI-21.2 is a  ∼  100-year long period with δ18O values 3–4 ‰ higher than the following  ∼  200 years of stadial conditions (GS-21.2), which precede the major GI-21.1 warming. We report concentrations of major elements indicative of dust and/or sea salt (Na, Fe, Al, Ca, Mg) at a spatial resolution of  ∼  200 µm, while maintaining detection limits in the low-ppb range, thereby achieving sub-annual time resolution even in deep NGRIP ice. We present an improved external calibration and quantification procedure using a set of five ice standards made from aqueous (international) standard solutions. Our results show that element concentrations decrease drastically (more than 10-fold) at the warming onset of GI-21.2 at the scale of a single year, followed by relatively low concentrations characterizing the interstadial part before gradually reaching again typical stadial values.


2020 ◽  
Author(s):  
Pascal Bohleber ◽  
Marco Roman ◽  
Carlo Barbante ◽  
Barbara Stenni ◽  
Barbara Delmonte

<p>Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) offers minimally destructive ice core impurity analysis at micron-scale resolution. This technique is especially suited for exploring closely spaced layers of ice within samples collected at low accumulation sites or in regions of highly compressed and thinned ice. Accordingly, LA-ICP-MS promises invaluable insights in the analysis of a future “Oldest ice core” from Antarctica. However, in contrast to ice core melting techniques, taking into account the location of impurities is crucial to avoid misinterpretation of ultra-fine resolution signals obtained from newly emerging laser ablation technologies. Here we present first results from a new LA-ICP-MS setup developed at the University of Venice, based on a customized two-volume cryogenic ablation chamber optimized for fast wash-out times. We apply our method for high-resolution chemical imagining analysis of impurities in samples from intermediate and deep sections of the Talos Dome and EPICA Dome C ice cores. We discuss the localization of both soluble and insoluble impurities within the ice matrix and evaluate the spatial significance of a single profile along the main core axis. With this, we aim at establishing a firm basis for a future deployment of the LA-ICP-MS in an “Oldest Ice Core”. Moreover, our work illustrates how LA-ICP-MS may offer new means to study the impurity-microstructure interplay in deep polar ice, thereby promising to advance our understanding of these fundamental processes.</p>


2015 ◽  
Vol 61 (226) ◽  
pp. 233-242 ◽  
Author(s):  
Sharon B. Sneed ◽  
Paul A. Mayewski ◽  
W.G. Sayre ◽  
Michael J. Handley ◽  
Andrei V. Kurbatov ◽  
...  

AbstractIce cores provide a robust reconstruction of past climate. However, development of timescales by annual-layer counting, essential to detailed climate reconstruction and interpretation, on ice cores collected at low-accumulation sites or in regions of compressed ice, is problematic due to closely spaced layers. Ice-core analysis by laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) provides sub-millimeter-scale sampling resolution (on the order of 100 μm in this study) and the low detection limits (ng L−1) necessary to measure the chemical constituents preserved in ice cores. We present a newly developed cryocell that can hold a 1 m long section of ice core, and an alternative strategy for calibration. Using ice-core samples from central Greenland, we demonstrate the repeatability of multiple ablation passes, highlight the improved sampling resolution, verify the calibration technique and identify annual layers in the chemical profile in a deep section of an ice core where annual layers have not previously been identified using chemistry. In addition, using sections of cores from the Swiss/Italian Alps we illustrate the relationship between Ca, Na and Fe and particle concentration and conductivity, and validate the LA-ICP-MS Ca profile through a direct comparison with continuous flow analysis results.


2021 ◽  
Vol 15 (7) ◽  
pp. 3523-3538
Author(s):  
Pascal Bohleber ◽  
Marco Roman ◽  
Martin Šala ◽  
Barbara Delmonte ◽  
Barbara Stenni ◽  
...  

Abstract. Due to its micrometer-scale resolution and inherently micro-destructive nature, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is particularly suited to exploring the thin and closely spaced layers in the oldest sections of polar ice cores. Recent adaptions to the LA-ICP-MS instrumentation mean we have faster washout times allowing state-of-the-art 2-D imaging of an ice core. This new method has great potential especially when applied to the localization of impurities on the ice sample, something that is crucial, to avoiding misinterpretation of the ultra-fine-resolution signals. Here we present the first results of the application of LA-ICP-MS elemental imaging to the analysis of selected glacial and interglacial samples from the Talos Dome and EPICA Dome C ice cores from central Antarctica. The localization of impurities from both marine and terrestrial sources is discussed, with special emphasis on observing a connection with the network of grain boundaries and differences between different climatic periods. Scale-dependent image analysis shows that the spatial significance of a single line profile along the main core axis increases systematically as the imprint of the grain boundaries weakens. It is demonstrated how instrumental settings can be adapted to suit the purpose of the analysis, i.e., by either employing LA-ICP-MS to study the interplay between impurities and the ice microstructure or to investigate the extremely thin climate proxy signals in deep polar ice.


2021 ◽  
Vol 3 ◽  
Author(s):  
Pascal Bohleber ◽  
Marco Roman ◽  
Carlo Barbante ◽  
Sebastiano Vascon ◽  
Kaleem Siddiqi ◽  
...  

Polar ice cores play a central role in studies of the earth’s climate system through natural archives. A pressing issue is the analysis of the oldest, highly thinned ice core sections, where the identification of paleoclimate signals is particularly challenging. For this, state-of-the-art imaging by laser-ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) has the potential to be revolutionary due to its combination of micron-scale 2D chemical information with visual features. However, the quantitative study of record preservation in chemical images raises new questions that call for the expertise of the computer vision community. To illustrate this new inter-disciplinary frontier, we describe a selected set of key questions. One critical task is to assess the paleoclimate significance of single line profiles along the main core axis, which we show is a scale-dependent problem for which advanced image analysis methods are critical. Another important issue is the evaluation of post-depositional layer changes, for which the chemical images provide rich information. Accordingly, the time is ripe to begin an intensified exchange between the two scientific communities of computer vision and ice core science. The collaborative building of a new framework for investigating high-resolution chemical images with automated image analysis techniques will also benefit the already wide-spread application of laser-ablation inductively-coupled plasma mass spectrometry chemical imaging in the geosciences.


2020 ◽  
Author(s):  
Pascal Bohleber ◽  
Marco Roman ◽  
Martin Šala ◽  
Barbara Delmonte ◽  
Barbara Stenni ◽  
...  

Abstract. Due to its micron-scale resolution and micro-destructiveness, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is especially suited for exploring closely spaced layers in the oldest and highly thinned sections of polar ice cores. Recent adaptions of the LA-ICP-MS technique have achieved fast washout times as the basis for introducing state-of-the-art 2D imaging to ice core analysis. This new method has great potential in its application for investigating the localization of impurities on the ice sample, crucial to avoid misinterpretation of ultra-fine resolution signals. Here first results are presented from applying LA-ICP-MS elemental imaging to selected glacial and interglacial samples of the Talos Dome and EPICA Dome C ice cores from central Antarctica. The localization of impurities with both marine and terrestrial sources is discussed, revealing generally a strong connection with the network of grain boundaries but also distinct differences among climatic periods. Scale-dependent image analysis shows that the spatial significance of a single line profile along the main core axis increases systematically as the imprint of grain boundaries weakens. With this, it is demonstrated how instrumental settings can be adapted specifically fit-for-purpose, i.e. either to employ LA-ICP-MS to study the impurity-microstructure interplay or to investigate highly thinned climate proxy signals in deep polar ice.


2014 ◽  
Vol 60 (219) ◽  
pp. 103-112 ◽  
Author(s):  
Bess G. Koffman ◽  
Michael J. Handley ◽  
Erich C. Osterberg ◽  
Mark L. Wells ◽  
Karl J. Kreutz

AbstractTo assess the role of methodological differences on measured trace-element concentrations in ice cores, we developed an experiment to test the effects of acidification strength and time on dust dissolution using snow samples collected in West Antarctica and Alaska. We leached Antarctic samples for 3 months at room temperature using nitric acid at concentrations of 0.1, 1.0 and 10.0% (v/v). At selected intervals (20 min, 24 hours, 5 days, 14 days, 28 days, 56 days, 91 days) we analyzed 23 trace elements using inductively coupled plasma mass spectrometry. Concentrations of lithogenic elements scaled with acid strength and increased by 100–1380% in 3 months. Incongruent elemental dissolution caused significant variability in calculated crustal enrichment factors through time (factor of 1.3 (Pb) to 8.0 (Cs)). Using snow samples collected in Alaska and acidified at 1% (v/v) for 383 days, we found that the increase in lithogenic element concentration with time depends strongly on initial concentration, and varies by element (e.g. Fe linear regression slope = 1.66; r = 0.98). Our results demonstrate that relative trace-element concentrations measured in ice cores depend on the acidification method used.


Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 535
Author(s):  
Franca Piera Caucia ◽  
Luigi Marinoni ◽  
Maurizio Scacchetti ◽  
Maria Pia Riccardi ◽  
Omar Bartoli

In Val d’Ala (Western Alps in Piedmont, Italy), the most interesting rocks for mineralogical research are represented by rodingite (rich in mineralized veins and fractures) associated with serpentinite in the eclogitized oceanic crust of Piedmont Zone, south of Gran Paradiso Massif. Among the vein-filling minerals, vesuvianite is well appreciated for its potential as gem-quality materials, even though it has never been characterized in detail. This study provides a gemological characterization of eleven vesuvianite crystals from different localities of the Val d’Ala. The refractive index (1.717–1.708) and density (1.705–1.709) values of our vesuvianite are in the range of those in the literature. Scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) established that the samples are pretty compositionally homogeneous in terms of major elements, while trace and rare earth elements (REE) contents are more variable. All REE patterns are characterized by pronounced positive Eu anomalies. The variations in color (from olive green to dark green with chocolate (reddish-brown color shades and polychrome bands) are due to the relevant presence of Fe and, to a lesser extent, Ti and Cr. The X-ray powder diffraction (XRPD) analyses and SEM/EDS quantitative study indicate that the other phases associated with vesuvianite are represented by diopside, garnet, clinochlore.


2019 ◽  
Vol 37 (3) ◽  
pp. 1162-1181 ◽  
Author(s):  
Yun Xu ◽  
Handong Liang ◽  
Ning Zhang

Minerals in coal are of great significance in determining coal properties, washing, combustion, gasification, and liquefaction. The content of alkali metals in coal is an important factor determining corrosion and/or erosion in combustion boilers. Eleven coal samples were taken from the No. 6 coal seam of the Fukang mining area, Zhunnan coalfield, Xinjiang province, China. X-ray fluorescence, inductively coupled plasma-mass spectrometry, low-temperature ashing-X-ray diffraction, and electron probe microanalyzer were used for analyzing the minerals, major elements, and trace elements of the coal. The results indicated that the minerals mainly consist of dawsonite, dolomite, albite, calcite, kaolinite, quartz. The average content of Na2O in the ash of the No. 6 coal seam samples was 10.91%. Na mainly occurs in the form of organic compounds in the No. 6 coal seam, then in the form of inorganic minerals, such as dawsonite and albite. Na in surface and underlying strata was brought into the coal by water and combined with organic matter, resulting in relatively high Na contents in the upper and bottom parts of the coal seam and relatively low Na contents in the middle part.


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