Geological age by instrumental analysis: the 29th Hallimond Lecture

1999 ◽  
Vol 63 (3) ◽  
pp. 297-311 ◽  
Author(s):  
W. Compston
Keyword(s):  
Laser Ablation ◽  
Spatial Resolution ◽  
Analytical Method ◽  
Bimodal Distribution ◽  
Instrumental Analysis ◽  
Hole Depth ◽  
Future Developments ◽  
Geological Age ◽  
Age Determinations

AbstractThe need in geology for in situ U-Pb age determinations of minerals is illustrated by two examples: the internal age dispersion developed within the zircon SL13 shortly after original crystallization, and the occurrence within minerals of old cores and later overgrowths. SL13 contains rare μm-sized patches of unsupported radiogenic Pb and a mainly bimodal distribution of 206Pb/238U ages otherwise. Both observations are consistent with original crystallization at 580 Ma and Pb loss at 565 Ma. Age precision is controlled by the ions counted for radiogenic Pb, and varies with instrumental sensitivity, age and U contents of the target. Laser-ablation ICPMS has similar spatial resolution and sensitivity to SIMS but consumes more sample because of much greater hole-depth in practice. Like SIMS, the measured Pb+/U+ is biased and also changes with depth so comparison with a standard mineral is necessary. Analyses of reference zircons reported here indicate that the reproducibility of Pb/U ages by ICPMS is limited by residual bias, not ion counting errors. For multipurpose ICPMS at least, the Hg background at mass 204 prohibits the measurement of 204Pb for common Pb estimation. A third micro-analytical method, ‘CHIME’, and future developments in SIMS and ICPMS are discussed briefly.

Measurements of bio-signature in ancient micrometre-sized fossils with a miniature laser mass spectrometer

2020 ◽  
Author(s):  
Marek Tulej ◽  
Rustam Lukmanov ◽  
Andreas Riedo ◽  
Valentine Grimaudo ◽  
Coenraad de Koning ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Chemical Composition ◽  
Mass Spectrometer ◽  
Spatial Resolution ◽  
Ionization Mass ◽  
Camera System ◽  
Laser Mass Spectrometer ◽  
Ionisation Mass

<p>Searches for the past and present life on the planetary surfaces will be involving multilevel characterisation of the planetary rocks and soils within potentially habitable environments. Some up to three billion years old stromatolites or fossilised bacterial colonies are particularly interesting. They are found on the Earth and thought to be earliest life forms preserved within the terrestrial sedimentary rocks and can be a benchmark for searches of bio-relevant objects on planetary surfaces. By combining the microscope-camera system and mass analyser one can identify micro-fossilised material within the rocks by means of specific morphological details and characteristic chemical composition. We discuss the results of the studies on ancient microfossils obtained by space-born instrumentation, microscope-camera system combined with laser mass spectrometer. Both, the microscope imaging and chemical analyses can be conducted with micrometre spatial resolution. We demonstrate that the morphological record is helpful but not sufficient to identify bio-relevant material. Yet, while combined with elemental and isotope and with help depth profiling method, the compositional analysis can distinguish between abiotic and biological nature of the material. Detection of biosignature in measurements of fossilised materials with a miniature laser ablation ionisation mass analyser.</p> <p> </p> <p>[1] M. Tulej, A. Neubeck, M. Ivarsson, A. Riedo, M.B. Neuland, S. Meyer, P. Wurz, Chemical Composition of Micrometer-Sized Filaments in an Aragonite Host by a Miniature Laser Ablation/Ionization Mass Spectrometer, Astrobiology, 15 (2015) 669-682.</p> <p>[2] A. Neubeck, M. Tulej, M. Ivarsson, C. Broman, A. Riedo, S. McMahon, P. Wurz, S. Bengtson, Mineralogical determination in situ of a highly heterogeneous material using a miniaturized laser ablation mass spectrometer with high spatial resolution, International Journal of Astrobiology, 15 (2016) 133-146.</p> <p>[3] R. Wiesendanger, D. Wacey, M. Tulej, A. Neubeck, M. Ivarsson, V. Grimaudo, P. Moreno-Garcia, A. Cedeno-Lopez, A. Riedo, P. Wurz, Chemical and optical identification of micrometer-sized 1.9 billion-year-old fossils by combining a miniature laser ablation ionization mass spectrometry system with an optical microscope, Astrobiology, 18 (2018) 1071-1080.</p> <p>[4] A. Riedo, A. Bieler, M. Neuland, M. Tulej, P. Wurz, Performance evaluation of a miniature laser ablation time-of-flight mass spectrometer designed for in situ investigations in planetary space research, Journal of Mass Spectrometry, 48 (2013) 1-15.</p> <p>[5] M. Tulej, A. Riedo, M.B. Neuland, S. Meyer, P. Wurz, N. Thomas, V. Grimaudo, P. Moreno-Garcia, P. Broekmann, A. Neubeck, M. Ivarsson, CAMAM: A Miniature Laser Ablation Ionisation Mass Spectrometer and Microscope-Camera System for In Situ Investigation of the Composition and Morphology of Extraterrestrial Materials, Geostand Geoanal Res, 38 (2014) 441-466.</p>

Spectro-mechanical Characterization of Aromaticity and Maturity of Kerogens in Oil Shale at 6 nm Spatial Resolution

2018 ◽  
Author(s):  
Devon Jakob ◽  
Le Wang ◽  
Haomin Wang ◽  
Xiaoji Xu
Keyword(s):  
Spatial Resolution ◽  
Oil Shale ◽  
Infrared Imaging ◽  
Mechanical Characterization ◽  
Optical Diffraction ◽  
Chemical Compositions ◽  
Valuable Insight ◽  
Eagle Ford Shale

<p>In situ measurements of the chemical compositions and mechanical properties of kerogen help understand the formation, transformation, and utilization of organic matter in the oil shale at the nanoscale. However, the optical diffraction limit prevents attainment of nanoscale resolution using conventional spectroscopy and microscopy. Here, we utilize peak force infrared (PFIR) microscopy for multimodal characterization of kerogen in oil shale. The PFIR provides correlative infrared imaging, mechanical mapping, and broadband infrared spectroscopy capability with 6 nm spatial resolution. We observed nanoscale heterogeneity in the chemical composition, aromaticity, and maturity of the kerogens from oil shales from Eagle Ford shale play in Texas. The kerogen aromaticity positively correlates with the local mechanical moduli of the surrounding inorganic matrix, manifesting the Le Chatelier’s principle. In situ spectro-mechanical characterization of oil shale will yield valuable insight for geochemical and geomechanical modeling on the origin and transformation of kerogen in the oil shale.</p>

scholarly journals In-situ determination of antimony isotope ratios in Sb minerals by femtosecond LA-MC-ICP-MS

2021 ◽  
Author(s):  
Andreas Benjamin Kaufmann ◽  
Marina Lazarov ◽  
Stefan Kiefer ◽  
Juraj Majzlan ◽  
Stefan Weyer
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Femtosecond Laser Ablation ◽  
Isotope Ratios ◽  
Icp Ms

Here we present a method for in-situ determination of stable antimony (Sb) isotope compositions by ultraviolet (UV)-femtosecond-laser-ablation-multi-collector-ICP-MS (fs-LA-MC-ICP-MS). Metallic antimony and a number of Sb minerals (stibnite, senarmontite, chalcostibite, tetrahedrite,...

In situ deposition of ErNi2B2C films by pulsed laser ablation technique

1998 ◽  
Vol 299 (1-2) ◽  
pp. 15-22 ◽  
Author(s):  
A Canesi ◽  
M.R Cimberle ◽  
C Ferdeghini ◽  
A Diaspro ◽  
P Guasconi ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Ablation Technique ◽  
In Situ Deposition ◽  
Laser Ablation Technique

Accuracy of laser-ablation (LA)-MC-ICPMS Sr isotope analysis of (bio)apatite – a problem reassessed

2016 ◽  
Vol 31 (1) ◽  
pp. 259-269 ◽  
Author(s):  
Wolfgang Müller ◽  
Robert Anczkiewicz
Keyword(s):  
Laser Ablation ◽  
Isotope Analysis ◽  
Sr Isotope ◽  
Plasma Laser ◽  
Interference Correction

Accurate in situ Sr isotope analysis of (bio)apatite via ‘robust-plasma’ laser-ablation MC-ICPMS with negligible 40Ca31P16O and reliable 87Rb interference correction.

Sign in / Sign up

Export Citation Format

Share Document