| Autor: |
Richard Triplett, Sarah C. Stafford, Gabriel D. Gwanmesia, Aaron M. Stafford, Donald G. Isaak, Michael G. Davis |
| Rok vydání: |
2010 |
| Předmět: |
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| Zdroj: |
Physics of the Earth and Planetary Interiors. 182:107-112 |
| ISSN: |
0031-9201 |
| DOI: |
10.1016/j.pepi.2010.06.014 |
| Popis: |
Data are presented on the elastic properties of β-(Mg 0.92 Fe 0.08 ) 2 SiO 4 (iron-bearing wadsleyite) from 295 K to 640 K at ambient pressure. Elasticity measurements were made on hot-pressed polycrystals using resonant ultrasound spectroscopy (RUS). Multiple temperature excursions were done with data retrieved during both heating and cooling cycles. Room temperature (RT) values for the adiabatic bulk ( K S ) and shear ( G ) moduli are 170.8(1.2) GPa and 108.9(0.4) GPa, respectively. The average derivatives over the temperature ( T ) range studied are (∂ K S /∂ T ) P = −1.75(0.07) × 10 −2 GPa K −1 and (∂ G /∂ T ) P = −1.55(0.06) × 10 −2 GPa K −1 . Comparison of these results with those from our recent study of Mg-endmember wadsleyite shows no measurable difference in the average (∂ K S /∂ T ) P or (∂ G /∂ T ) P from RT to 640 K due to Fe content. Slight nonlinearity in the temperature dependences of both K S and G are observed, such that second order fits for both K S ( T ) and G ( T ) are statistically justified. Whereas, the current nonlinearity in G ( T ) for β-(Mg 0.92 Fe 0.08 ) 2 SiO 4 is similar to that observed for β -Mg 2 SiO 4 , second order effects in K S ( T ) were not observed previously for wadsleyite. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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