Electron Microprobe/SIMS Determinations of Al in Olivine: Applications to Solar Wind, Pallasites and Trace Element Measurements
Abstract
Electron probe microanalyser measurements of trace elements with high accuracy are challenging. Accurate Al measurements in olivine are required to calibrate SIMS implant reference materials for measurement of Al in the solar wind. We adopt a combined EPMA/SIMS approach that is useful for producing SIMS reference materials as well as for EPMA at the ~100 µg g⁻¹ level. Even for mounts not polished with alumina photoelectron spectroscopy shows high levels of Al surface contamination. In order to minimise electron beam current density, a rastered 50 × 100 µm electron beam was adequate and minimised sensitivity to small Al‐rich contaminants. Reproducible analyses of eleven SIMS cleaned spots on San Carlos olivine agreed at 69.3 ± 1.0 µg g⁻¹. The known Al mass fraction was used to calibrate an Al implant into San Carlos. Accurate measurements of Al were made for olivines in the pallasites: Imilac, Eagle Station and Springwater. Our focus was on Al in olivine; but our technique could be refined to give accurate electron probe measurements for other contamination‐sensitive trace elements. For solar wind it is projected that the Al/Mg abundance ratio can be determined to 6%, a factor of 2 more precise than the solar spectroscopic ratio.
Additional Information
© 2020 The Authors. Geostandards and Geoanalytical Research © 2020 International Association of Geoanalysts. Issue Online: 12 August 2020; Version of Record online: 21 July 2020; Accepted manuscript online: 08 June 2020; Manuscript accepted: 26 May 2020; Manuscript received: 05 December 2019. Funding: National Aeronautics and Space Administration. Grant Number: 89NSSC17K0025.Attached Files
Supplemental Material - ggr12347-sup-0001-appendix-a.pdf
Supplemental Material - ggr12347-sup-0002-appendix-b.pdf
Supplemental Material - ggr12347-sup-0003-appendix-c.pdf
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Additional details
- Eprint ID
- 103775
- Resolver ID
- CaltechAUTHORS:20200608-133209595
- 89NSSC17K0025
- NASA
- Created
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2020-06-08Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences