Abstract
Jeffbenite (Mg3Al2Si3O12) is a tetragonal phase found in so far only in superdeep diamonds, and its thermoelastic parameters are a prerequisite for determining entrapment pressures as it is regarded as a potential indicator for superdeep diamonds. In this study, the thermoelastic properties of synthetic Fe3+-jeffbenite were measured up to 33.7 GPa and 750 K. High-temperature static compression data were fitted, giving (∂KT0/∂T)P = −0.0107 (4) GPa/K and αT = 3.50 (3) × 10−5 K−1. The thermoelastic properties and phase stability are applied to modeling isomekes, or P-T paths intersecting possible conditions of entrapment in diamond. We calculate that under ideal exhumation, jeffbenite entrapped at mantle transition zone conditions will exhibit a high remnant pressure at 300 K (Pinc) of ∼5.0 GPa. Elastic geobarometry on future finds of jeffbenite inclusions can use the new equation of state to estimate entrapment pressures for this phase with still highly uncertain stability field in the mantle.
Original language | English (US) |
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Article number | e2023GL106908 |
Journal | Geophysical Research Letters |
Volume | 51 |
Issue number | 6 |
DOIs | |
State | Published - Mar 28 2024 |
Funding
This research was supported by National Natural Science Foundation of China (Grant 42202040) and the SinoProbe laboratory of Chinese Academy of Geological Sciences (Grant 202208). SDJ Acknowledges support from the US National Science Foundation grant EAR‐1853521. Work performed at GSECARS (Sector 13) of the Advanced photon Source (APS) is supported by the NSF EAR‐1634415 and the Department of Energy (DOE) DE‐FG02‐94ER1446. The APS at Argonne National Laboratory is supported by the DOE, Office of Science, under Contract No. DE‐AC02‐06CH11357. Experiments at Sector 13‐BM‐C of the APS used the PX^2 facility, supported by GSECARS and COMPRES under NSF Cooperative Agreement EAR‐1661511. Use of the COMPRES‐GSECARS gas loading system was supported by COMPRES under NSF Cooperative Agreement EAR‐1606856. This research was supported by National Natural Science Foundation of China (Grant 42202040) and the SinoProbe laboratory of Chinese Academy of Geological Sciences (Grant 202208). SDJ Acknowledges support from the US National Science Foundation grant EAR-1853521. Work performed at GSECARS (Sector 13) of the Advanced photon Source (APS) is supported by the NSF EAR-1634415 and the Department of Energy (DOE) DE-FG02-94ER1446. The APS at Argonne National Laboratory is supported by the DOE, Office of Science, under Contract No. DE-AC02-06CH11357. Experiments at Sector 13-BM-C of the APS used the PX^2 facility, supported by GSECARS and COMPRES under NSF Cooperative Agreement EAR-1661511. Use of the COMPRES-GSECARS gas loading system was supported by COMPRES under NSF Cooperative Agreement EAR-1606856.
ASJC Scopus subject areas
- Geophysics
- General Earth and Planetary Sciences