Microanalysis of carbon isotope composition in organic matter by secondary ion mass spectrometry

Sangely, L.; Chaussidon, M.; Michels, Raymond; Huault, Vincent

doi:10.1016/j.chemgeo.2005.06.001

Cited by 40 publications

(37 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since instrumental isotope fractionation is influenced by the chamber vacuum, the chamber pressure was kept below 1 · 10 À8 Torr during the entire session (Sangely et al, 2005). Several organic carbon standards for SIMS d 13 C analysis have been used here (described by Sangely et al, 2005). These materials represent a range in H/C-, O/C-, and N/C-ratio, and are therefore also suitable as standards for SIMS N/C-ratio analysis.…”

Section: Sims (Secondary Ion Mass Spectrometry)mentioning

confidence: 99%

“…Secondary 13 C À and 12 C À ions were simultaneously measured in multicollection mode. Since instrumental isotope fractionation is influenced by the chamber vacuum, the chamber pressure was kept below 1 · 10 À8 Torr during the entire session (Sangely et al, 2005). Several organic carbon standards for SIMS d 13 C analysis have been used here (described by Sangely et al, 2005).…”

Section: Sims (Secondary Ion Mass Spectrometry)mentioning

confidence: 99%

See 1 more Smart Citation

Carbonaceous cherts of the Barberton Greenstone Belt, South Africa: Isotopic, chemical and structural characteristics of individual microstructures

Zuilen

Chaussidon

Rollion‐Bard

et al. 2007

Geochimica et Cosmochimica Acta

Self Cite

View full text Add to dashboard Cite

Section: Sims (Secondary Ion Mass Spectrometry)mentioning

confidence: 99%

Section: Sims (Secondary Ion Mass Spectrometry)mentioning

confidence: 99%

Carbonaceous cherts of the Barberton Greenstone Belt, South Africa: Isotopic, chemical and structural characteristics of individual microstructures

Zuilen

Chaussidon

Rollion‐Bard

et al. 2007

Geochimica et Cosmochimica Acta

Self Cite

View full text Add to dashboard Cite

“…Since deriving in situ H/C atomic ratios from measured α H values has not been calibrated because of matrix effects, it is not possible to argue that these different α H values for different microfossil populations are solely caused by variations of their H content. Nonetheless, H content is a function of aliphatic moieties contained in OM, leading to emission matrix effects (Sangely et al, 2005(Sangely et al, , 2007. Thus, the differences in α H values determined for filamentous microfossils and spheroid acritarchs may point to differences in their H and/or aliphatic contents.…”

Section: Taphonomic and Precursor Geochemical Signatures As Revealed mentioning

confidence: 99%

“…species, and in turn molecular ion ratios, through the so-called "matrix effects" (Sangely et al, 2005(Sangely et al, , 2007Lepot et al, 2013). However, there has been no systematic study investigating whether biases introduced by microtopography and matrix effects preclude distinction of the geochemical composition of organic-walled microfossil population(s) or not.…”

Section: Introductionmentioning

confidence: 99%

Can NanoSIMS probe quantitatively the geochemical composition of ancient organic-walled microfossils? A case study from the early Neoproterozoic Liulaobei Formation

Delarue

Robert

Tartèse

et al. 2018

Precambrian Research

View full text Add to dashboard Cite

Assessing the biogenicity of Precambrian putative remnants of life requires solid criteria. Among possible criteria, searching for evidence of pristine biological signatures and identifying various biological organic matter (OM) precursors in close association with microfossil morphology are of interest. Nano-scale Secondary Ion Mass Spectrometry (NanoSIMS) can provide a quantitative geochemical proxy at the scale of the individual microfossil but its use has remained limited because of potential analytical biases related to matrix effects and microtopography that may result in inaccurate NanoSIMS-derived measurement. No study so far has assessed whether these potential analytical biases were strong enough to preclude any identification of pristine OM degradation products and of organic precursors in ancient sediments. In this study, we characterized the geochemical composition of organic-walled microfossils from the early Neoproterozoic Liulaobei Formation in North China using NanoSIMS. The 12 CH − / 12 C 2 − ionic ratio allows us to distinguish filament from spheroid acritarchs, revealing the co-occurrence of two distinct pristine OM signatures that differ by their H and/or aliphatic contents. In addition, NanoSIMS data show that morphological degradation was tightly linked to a loss of H and/or hydrogenated organic compounds in spheroid acritarchs. In contrast, in situ N/C atomic ratios are homogeneous across all organic-walled microfossils studied. Although highly coherent with Proterozoic N/C atomic ratios from the literature, such homogeneity may alternatively reflect (i) a similar N content for different organic precursors or (ii) an extensive homogenization related to early degradation. Overall, these data obtained on microfossils from the Proterozoic Liulaobei Formation are the first to demonstrate that the quantitative capability of NanoSIMS can be used to track ancient OM precursors and to probe the effects of degradation on pristine OM. These findings open up tremendous perspectives and put forward new criteria for assessing the biogenicity of the putative early traces of life found in Archean metasediments.

show abstract

“…Sangely et al, 2005). When the vacuum is poor, the probability that secondary ions strike particles present in the specimen chamber is increased and thus disturb the ion yield.…”

Section: Pressure In the Specimen Chambermentioning

confidence: 99%

In situ measurements of calcium isotopes by ion microprobe in carbonates and application to foraminifera

Rollion‐Bard¹,

Vigier²,

Spezzaferri³

2007

Chemical Geology

View full text Add to dashboard Cite

An analytical procedure has been developed for the in situ measurement of calcium isotope composition of carbonates with a spatial resolution of 15-20 μm on a Caméca IMS 1270 ion microprobe. By using two Faraday cup detectors, the 40 Ca and 44 Ca can be measured simultaneously, improving the internal reproducibility. Instrumental mass fractionation (IMF) of calcium isotopes was observed to be independent of primary ion beam intensity and of the Mg content of the carbonate, but can depend on vacuum conditions. Three calcite reference materials were used in this study (ENS 0, MEX and BRET 105E) and their δ 44 Ca values relative to NIST915a were reproducible within a typical 1σ standard deviation of ≈0.15‰.This analytical procedure was applied to planktonic foraminifera, Globorotalia inflata, dated at 2.8 Ma from Shatsky Rise (ODP leg 198). The range of measured δ 44 Ca within a single test is 1.7‰. This intratest variation can be attributed to several processes such as temperature variation, ontogenic effects or differences between primary and secondary calcite (i.e. calcite precipitated by different biomineralization processes).Despite this intratest variation, the averages δ 44 Ca for each foraminifer are similar and are in agreement with published δ 44 Ca values measured for this age. This study shows that in situ δ 44 Ca measurements in tests of foraminifera are an appropriate tool for investigating biomineralization processes.

show abstract

Microanalysis of carbon isotope composition in organic matter by secondary ion mass spectrometry

Cited by 40 publications

References 34 publications

Carbonaceous cherts of the Barberton Greenstone Belt, South Africa: Isotopic, chemical and structural characteristics of individual microstructures

Carbonaceous cherts of the Barberton Greenstone Belt, South Africa: Isotopic, chemical and structural characteristics of individual microstructures

Can NanoSIMS probe quantitatively the geochemical composition of ancient organic-walled microfossils? A case study from the early Neoproterozoic Liulaobei Formation

In situ measurements of calcium isotopes by ion microprobe in carbonates and application to foraminifera

Contact Info

Product

Resources

About