The celestite problem in gypsum Sr geochemistry: An evaluation of purifying methods of gypsiferous samples

Playà, Elisabet; Rosell, Laura

doi:10.1016/j.chemgeo.2005.04.006

Cited by 29 publications

(7 citation statements)

References 31 publications

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“…A particular interesting result in the cryo-Raman investigation was the comparatively high amount of dolomite (CaMg(CO 3 ) 2 ) found in the sample S10. Although a clear Ca signal was not obtained for the maps, Sr can provide a tentative indicator in this context, since it has also been observed both in gypsum and dolomite (Playà & Rosell, 2005;Sánchez-Román et al, 2011). In a visual colocalization analysis (Figure S5 in Supporting Information S1), Sr occurs occasionally on its own.…”

Section: Geochemical Signature Of Particle Clustersmentioning

confidence: 95%

Geochemical Characterization of Insoluble Particle Clusters in Ice Cores Using Two‐Dimensional Impurity Imaging

Bohleber

Stoll

Rittner

et al. 2023

Geochem Geophys Geosyst

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Polar ice cores are an invaluable archive of past climate, thanks to recording a unique variety of proxies such as greenhouse gas concentrations and aerosol-related atmospheric impurity records over time-scales from decades up to hundreds of millennia (e.g., Fischer et al., 2021). The investigation of the deepest and highly thinned ice core layers remains a fundamental frontier in ice core research, being the key to unlock the oldest parts of the ice core record. As a new 1.5 million year-old ice record may soon be recovered from Antarctica (Brook et al., 2006;Fischer et al., 2013), it is also an increasingly pressing challenge. Given that each meter of such an "Oldest" ice core section expected around 2,500 m depth at Little Dome C may comprise more than 10,000 years (Lilien Abstract Understanding post-depositional processes altering the layer sequence in ice cores is especially needed to avoid misinterpretation of the oldest and most highly thinned layers. The record of soluble and insoluble impurities represents an important part of the paleoclimate proxies in ice cores but is known to be affected through interaction with the ice matrix, diffusion, and chemical reactions. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been recognized for its micron-scale resolution and micro-destructiveness in ice core impurity analysis. Employing LA-ICP-MS for 2D chemical imaging has already revealed a close relationship between the ice grain boundary network and impurity signals with a significant soluble component, such as Na and Mg. Here we show the latest improvements in chemical imaging with LA-ICP-MS, by increasing the spatial resolution to 20 μm and extending the simultaneous analysis to also mostly insoluble impurities, such as Al and Fe. All analytes reveal signals of dispersed spots in a sample of an East Greenland ice core. Based on their average size around 50-60 times larger than an average particle and their heterogeneous elemental ratios these spots are interpreted as particle clusters. To distinguish their origin, a simple colocalization classification reveals elemental ratios consistent with marine and mineral dust aerosol. Based on already existing data from cryo-Raman spectroscopy, we discuss potential ways to integrate the two methods in a future comparison. Such a combined approach may help constraining post-depositional changes to the dust-related insoluble impurity components, such as cluster formation and chemical reactions at grain boundaries.Plain Language Summary Aerosols of marine and terrestrial origin delivered to the polar ice sheets are archived in the ice and can be studied via the analysis of ice cores. The chemical composition and size of mineral dust can deliver important information about past climatic changes and atmospheric transport. However, it has already been shown that this insoluble material is not always passively archived in the ice but can undergo changes in its chemical composition and size, for example, by forming particle aggregates. To investigat...

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Section: Geochemical Signature Of Particle Clustersmentioning

confidence: 95%

Geochemical Characterization of Insoluble Particle Clusters in Ice Cores Using Two‐Dimensional Impurity Imaging

Bohleber

Stoll

Rittner

et al. 2023

Geochem Geophys Geosyst

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“…All the powdered gypsum samples were first reacted with HCl 2 N before carrying out the geochemical analyses, to remove carbonate fraction and part of celestite content (Lucchesi & Whitney 1962;Play a & Rosell 2005).…”

Section: Methodsmentioning

confidence: 99%

“…The Sr contents in gypsum could come from direct incorporation from brine to crystals during crystallization or from external Sr inputs by means of celestite contamination or rubidium decay (Rosell et al 1998;Play a & Rosell 2005). Rb and Sr contents were analysed to guarantee the Sr origin.…”

Section: Fluid Flow Evolutionmentioning

confidence: 99%

Diagenetic evolution of a fractured evaporite deposit (Vilobí Gypsum Unit, Miocene, NE Spain)

Moragas¹,

Martínez

Baqués

et al. 2013

Geofluids

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The upper Burdigalian Vilobí Gypsum Unit, located in the Vallès Penedès half‐grabben (NE Spain), consists of a 60‐m thick succession of laminated‐to‐banded secondary and primary gypsum affected by Neogene extension in the western part of Mediterranean Sea. This Tertiary extensional event is recorded in the evaporitic unit as six fracture sets (faults and joints), which can be linked with basin‐scale deformation stages. All fractures are totally or partially infilled by four types of new gypsum precipitates showing a large variety of textures and microstructures. A structural and petrological study of the unit allows us to establish the following chronology of the fracture formation and infilling processes, from oldest to youngest: (i) S1 and S2 normal faults sets formation and precipitation of sigmoidal gypsum fibres; (ii) S3 joint set formation and growing of perpendicular fibres; (iii) S4 inverse fault development, infilled by oblique gypsum fibres and deformation of the previous fillings; and (iv) S5 and S6 joint formations and later dissolution processes, infilled by macrocrystalline gypsum cements. The fractures provided the pathway for fluid circulation in the Vilobí Unit. The oxygen, sulphur and strontium isotope compositions of the host rocks and the new precipitates in the fractures suggest clear convective recycling processes from the host‐sulphates to the fracture infillings, recorded by a general enrichment trend to heavier S–O isotopes, from the oldest precipitates (sigmoidal fibres) to the youngest (macrocrystalline cements) and to the preservation of the strontium signals in the infillings.

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“…Energy Dispersive X-ray Fluorescence spectrometry (EDXRF), performed in-situ in the two paintings gave relevant elemental composition information about ground layers in the lacunae areas of the painting layers. On the later, EDXRF detected the concomitant presence of S, Ca and small amount of Sr which is compatible with a preparation composed of a calcium sulfate matrix with strontium in the gypsum crystalline structure or strontium sulfates as a minor component [16]- [19]. The Ca intensities (arbitrary units) obtained by XRF, showed by a variability in the Ca Kα line areas, indicate a higher amount of Ca (38% more) in the painting Ressurreic ¸ão than in Adorac ¸ão dos Pastores (table 1).…”

Section: Resultsmentioning

confidence: 57%

GREGÓRIO LOPES painting workshop: characterization by X-ray based techniques. Analysis by EDXRF, μ-XRD and SEM-EDS

et al. 2014

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Gregório Lopes is one of the most famous Portuguese painters of the 15 th -16 th centuries. This work is a contribution to the study of his painting technique, specifically addressing the methodology used in the preparation of ground layers, which has never been carried out previously with this multianalytical method.For this purpose characterization of the ground layers of a selection of his paintings was carried out by micro-Energy Dispersive X-ray Fluorescence spectroscopy (µ-EDXRF), micro-X-ray Diffraction (µ-XRD), Scanning Electron Microscopy -Energy Dispersive Spectroscopy (SEM-EDS) and complemented by micro-Raman spectroscopy. This work presents the results obtained on two altarpieces (c.1544) produced at the same period by this Portuguese artist. Ground layers are composed mainly of calcium sulfate -anhydrite and gypsum -and other compounds such as dolomite. Reference samples were prepared to obtain diffraction pattern of different percentage of gypsum and anhydrite and compared with the results from historical samples.

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The celestite problem in gypsum Sr geochemistry: An evaluation of purifying methods of gypsiferous samples

Cited by 29 publications

References 31 publications

Geochemical Characterization of Insoluble Particle Clusters in Ice Cores Using Two‐Dimensional Impurity Imaging

Geochemical Characterization of Insoluble Particle Clusters in Ice Cores Using Two‐Dimensional Impurity Imaging

Diagenetic evolution of a fractured evaporite deposit (Vilobí Gypsum Unit, Miocene, NE Spain)

GREGÓRIO LOPES painting workshop: characterization by X-ray based techniques. Analysis by EDXRF, μ-XRD and SEM-EDS

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