Equation of State of CAS Phase to Pressure of the Uppermost Lower Mantle at Ambient Temperature
The CAS phase is a major constituent phase for the continental crust and basaltic compositions at the P-T conditions of the Earth's mantle, and potentially plays an important role in the geodynamic processes related to slab subduction. Its equation of state has been investigated here at ambient temperature up to about 25 GPa by using a diamond-anvil cell and synchrotron X-ray radiation. Its P-V data, fitted to the third-order Birch-Murnaghan equation, yield an isothermal bulk modulus (K'{sub T}) of 185 (9) GPa and first pressure derivative (K'{sub T} ) of 7.2 (12). If K'{sub T} is fixed at 4, the derived K{sub T} is 212 (4) GPa. Additionally, the CAS phase is strongly elastically anisotropic, with its a-axis direction much less compressible than c-axis direction: K{sub T-a}:K{sub T-c} = 2.19.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE SC OFFICE OF SCIENCE (SC)
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1042334
- Report Number(s):
- BNL-98012-2012-JA; TRN: US201212%%744
- Journal Information:
- Science China Earth Sciences, Vol. 54, Issue 9; ISSN 1674-7313
- Country of Publication:
- United States
- Language:
- English
Similar Records
Subduction recycling of continental sediments and the origin of geochemically enriched reservoirs in the deep mantle
Thermal Equation of State of Natural Ti-Bearing Clinohumite