Discovery of tetragonal almandine, (Fe,Mg,Ca,Na)_3(Al,Si,Mg)_2Si_3O_(12), a new high-pressure mineral in Shergotty
- Creators
- Ma, Chi
- Tschauner, Oliver
Abstract
Introduction: During a nanomineralogy investigation of the Shergotty meteorite, we have identified a new shock-induced high-pressure silicate, majoritic almandine with a tetragonal I4_1/ɑ structure, in an impact melt pocket. Field-emission scanning electron microscope, electron back-scatter diffraction, electron microprobe and synchrotron diffraction were used to characterize its chemical composition, structure, and associated phases. Tetragonal majorite (Mg_3(SiMg)Si_3O_(12)) with the I4_1/ɑ structure was synthesized [e.g., 1] and found later in the Tenham chondrite [2,3]. Tetragonal almandine-pyrope phase (TAPP) with the I-42d structure was reported to occur as inclusions in lowermantle diamonds [4]. We present here the first occurrence of tetragonal almandine with the I41/a structure in a shocked meteorite from Mars as a new high-pressure phase.
Additional Information
© 2016 Wiley. First published: 20 July 2016.Attached Files
Published - Ma_2016p291.pdf
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Additional details
- Eprint ID
- 72960
- Resolver ID
- CaltechAUTHORS:20161220-075954459
- Created
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2016-12-20Created from EPrint's datestamp field
- Updated
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2020-03-09Created from EPrint's last_modified field