| Titre | Rapid geochemical imaging of rocks and minerals with handheld laser induced breakdown spectroscopy (LIBS) |
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| Auteur | Lawley, C J M; Somers, A M; Kjarsgaard, B A |
| Source | Journal of Geochemical Exploration 106694, 2020., https://doi.org/10.1016/j.gexplo.2020.106694 |
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| Année | 2020 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20200361 |
| Éditeur | Elsevier B.V. |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1016/j.gexplo.2020.106694 |
| Media | papier; en ligne; numérique |
| Formats | pdf; html |
| Province | Territoires du Nord-Ouest; Nunavut |
| Lat/Long OENS | -115.0000 -107.0000 67.1667 64.3333 |
| Sujets | spectroscopie; Craton de Slave ; l'apprentissage machine; Sciences et technologie; géochimie |
| Illustrations | cartes de localisation; tableaux; diagrammes; graphiques |
| Programme | Initiative géoscientifique ciblée (IGC-5) Systèmes minéralisés aurifères |
| Diffusé | 2020 11 11 |
| Résumé | (disponible en anglais seulement)
Geochemical imaging is a powerful tool for unravelling the complex geological histories of rocks and minerals. However, its applications has until recently been
restricted to research applications in a lab environment due to the cost and size of conventional instrumentation, long analysis times, and extensive sample preparation for some methods. Herein we present a rapid geochemical imaging method for rocks
and minerals using handheld LIBS. Analyzes were completed directly on sawed drill core surfaces for a suite of kimberlite-hosted mantle xenoliths (Jericho and Muskox kimberlite intrusions, Canada). Semi-automated LIBS spectral processing following a
new open-source workflow allows stitching of multiple small-area maps (each approximately 3 x 3 mm) to produce cm-scale geochemical images of altered mantle xenolith samples. We demonstrate with open-source machine learning tools how qualitative LIBS
spectral data can be converted to Feature-Of-Interest (FOI) maps to distinguish mineralogy, including differentiating primary mantle minerals from high (Cr diopside) - and low-T (kelephytic pyrope garnet) phase alteration. Our results further
demonstrate that the resolution of handheld LIBS-based geochemical imaging is sufficient to map mineral overgrowths, microscale veinlets, and grain boundaries lined with hydrothermal alteration minerals. The LIBS approach is particularly sensitive
for mapping the microscale distribution of elements with low atomic number (eg, Li and Na), which is challenging with other handheld technologies. |
| Sommaire | (Résumé en langage clair et simple, non publié)
The Targeted Geoscience Initiative (CGI) -5 program is developing new models and methods to improve targeting of mineral exploration in harsh
environments. Here we present a new method for mapping the composition of rocks and minerals. The new method is fast and requires very little sample preparation, which is important for minerals in remote areas that cannot always access conventional
research labs. We apply the new method to a series of rocks from the old Jericho diamond mine. |
| GEOSCAN ID | 327053 |
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