Jadeite and related species in shocked meteorites: Limitations on inference of shock conditions
Abstract
Jadeite is frequently reported in shocked meteorites, displaying a variety of textures and grain sizes that suggest formation by either solid-state transformation or by crystallization from a melt. Some-times, jadeite has been identified solely on the basis of Raman spectra. Here we argue that additional characterization is needed to confidently identify jadeite and distinguish it from related species. Based on chemical and spectral analysis of three new occurrences, complemented by first-principles calculations, we show that related pyroxenes in the chemical space (Na)ᴹ²(Al)ᴹ¹(Si₂)ᵀO₆–(Ca)ᴹ²(Al)ᴹ¹(AlSi)ᵀO₆–(☐)ᴹ²(Si)ᴹ¹(Si₂)ᵀO₆ with up to 2.25 atoms Si per formula unit have spectral features similar to jadeite. However, their distinct stability fields (if any) and synthesis pathways, considered together with textural constraints, have different implications for precursor phases and estimates of impactor size, encounter velocity, and crater diameter. A reassessment of reported jadeite occurrences casts a new light on many previous conclusions about the shock histories preserved in particular meteorites.
Additional Information
Ioannis Baziotis, Stamatios Xydous, and Angeliki Papoutsa received support for this research from ESF and the Greek State (call code EDBM103). Ioannis Baziotis thanks SYNTHESYS project AT-TAF-30 (www.synthesys.info; a European Union funded Integrated Activities grant), which provided travel, accommodation, and instrument costs while using SEM and EPMA instruments at NHMV. Stamatios Xydous greatly thanks the Barringer Family Fund for Meteorite Impact Research for its support. Analyses at Caltech were funded by NASA award 80NSSC18K0532. Razvan Caracas acknowledges support from the European Research Council under EU Horizon 2020 research and innovation program (grant agreement 681818–IMPACT), the Research Council of Norway, project number 223272, and access to supercomputing facilities via eDARI stl2816 grants, PRACE RA4947 grant, and Uninet2 NN9697K grant. The authors are grateful to Dan Topa for assistance with the EPMA analyses. We thank an anonymous reviewer for helpful review comments. We gratefully recognize the efforts by the associate editor Oliver Tschauner for his constructive and fruitful review comments, and editorial handling.Additional details
- Eprint ID
- 117401
- Resolver ID
- CaltechAUTHORS:20221013-48863000.11
- EDBM103
- European Social Fund
- 80NSSC18K0532
- NASA
- 681818
- European Research Council (ERC)
- 223272
- Research Council of Norway
- stl2816
- Demande d'Attribution de Ressources Informatiques (eDARI)
- RA4947
- Partnership for Advanced Computing in Europe (PRACE)
- NN9697K
- Norwegian Supercomputing Program (NOTUR)
- Created
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2022-10-18Created from EPrint's datestamp field
- Updated
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2022-10-18Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences