Empirical constraints on shock features in monazite using shocked zircon inclusions
Shock deformation microstructures in monazite have been systematically characterized for the first time in grains from the Vredefort impact structure in South Africa. Electron backscatter diffraction mapping has identified 12 unique orientations of monazite deformation twins, including 7 orientation...
| Main Authors: | , , , , |
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| Format: | Journal Article |
| Published: |
Geological Society of America
2016
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| Online Access: | http://purl.org/au-research/grants/arc/LE130100053 http://hdl.handle.net/20.500.11937/14505 |
| _version_ | 1848748640499138560 |
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| author | Erickson, T. Cavosie, Aaron Pearce, M. Timms, N. Reddy, S. |
| author_facet | Erickson, T. Cavosie, Aaron Pearce, M. Timms, N. Reddy, S. |
| author_sort | Erickson, T. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Shock deformation microstructures in monazite have been systematically characterized for the first time in grains from the Vredefort impact structure in South Africa. Electron backscatter diffraction mapping has identified 12 unique orientations of monazite deformation twins, including 7 orientations that have not previously been described in experiments or nature. Other shock features include planar deformation bands and strain-free neoblasts, which have been shown to date deformation. Shock-twinned zircon inclusions within the deformed monazite require pressures of 20 GPa, thus providing critical empirical constraints on formation conditions, confirming a hypervelocity impact origin of the monazite microstructures. The Vredefort monazite grains described here represent the first case of using shocked mineral inclusions to empirically calibrate shock microstructures formed in the host mineral. These results conclusively establish monazite as a recorder of shock deformation, and highlight its use in identifying and dating impact structures. |
| first_indexed | 2025-11-14T07:08:15Z |
| format | Journal Article |
| id | curtin-20.500.11937-14505 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:08:15Z |
| publishDate | 2016 |
| publisher | Geological Society of America |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-145052023-02-02T03:24:10Z Empirical constraints on shock features in monazite using shocked zircon inclusions Erickson, T. Cavosie, Aaron Pearce, M. Timms, N. Reddy, S. Shock deformation microstructures in monazite have been systematically characterized for the first time in grains from the Vredefort impact structure in South Africa. Electron backscatter diffraction mapping has identified 12 unique orientations of monazite deformation twins, including 7 orientations that have not previously been described in experiments or nature. Other shock features include planar deformation bands and strain-free neoblasts, which have been shown to date deformation. Shock-twinned zircon inclusions within the deformed monazite require pressures of 20 GPa, thus providing critical empirical constraints on formation conditions, confirming a hypervelocity impact origin of the monazite microstructures. The Vredefort monazite grains described here represent the first case of using shocked mineral inclusions to empirically calibrate shock microstructures formed in the host mineral. These results conclusively establish monazite as a recorder of shock deformation, and highlight its use in identifying and dating impact structures. 2016 Journal Article http://hdl.handle.net/20.500.11937/14505 10.1130/G37979.1 http://purl.org/au-research/grants/arc/LE130100053 Geological Society of America restricted |
| spellingShingle | Erickson, T. Cavosie, Aaron Pearce, M. Timms, N. Reddy, S. Empirical constraints on shock features in monazite using shocked zircon inclusions |
| title | Empirical constraints on shock features in monazite using shocked zircon inclusions |
| title_full | Empirical constraints on shock features in monazite using shocked zircon inclusions |
| title_fullStr | Empirical constraints on shock features in monazite using shocked zircon inclusions |
| title_full_unstemmed | Empirical constraints on shock features in monazite using shocked zircon inclusions |
| title_short | Empirical constraints on shock features in monazite using shocked zircon inclusions |
| title_sort | empirical constraints on shock features in monazite using shocked zircon inclusions |
| url | http://purl.org/au-research/grants/arc/LE130100053 http://hdl.handle.net/20.500.11937/14505 |