کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4742997 | 1641606 | 2006 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
P-V-T equation of state of MgSiO3 perovskite and MgO periclase: Implication for lower mantle composition
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موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
فیزیک زمین (ژئو فیزیک)
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The P-V-T equation of state (EOS) for magnesium silicate perovskite (MgSiO3) and periclase (MgO) was obtained by fitting measured P, V, T data. The EOS of MgSiO3 perovskite was determined by applying the Mie-Grüneisen-Debye approach, based on three alternative bulk modulus values (KT0 = 240, 250 and 261 GPa), yielding substantially different values for high-order thermoelastic parameters such as the Grüneisen parameter (γ) and the temperature derivative of bulk modulus ((âKT/âT)P). Combined with the EOS of magnesiowüstite, we calculated the density (Ï), bulk modulus (KS) and seismic parameter (Ï) for simplified pyrolitic lower mantle along a plausible adiabat (temperature at 670 km, Ta = 1900 K), and compared these values to those of a seismological model (PREM). The results based on KT0 of 261 GPa, which has been commonly used, showed good agreement with PREM, within 0.5% for Ï, and 2-3% for KS and Ï, throughout the lower mantle. The EOS obtained using the recent KT0 data (240-250 GPa), substantially overestimated KS and Ï by 5-10%, requiring a progressive enrichment in (Mg,Fe)O with increasing depth. In addition, a more realistic vibrational density of states (VDOS) model (Kieffer-type model) was applied to calculate the EOS. The effect of VDOS on thermoelastic parameters was not large enough to modify those conclusions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physics of the Earth and Planetary Interiors - Volume 155, Issues 1â2, 14 April 2006, Pages 87-95
Journal: Physics of the Earth and Planetary Interiors - Volume 155, Issues 1â2, 14 April 2006, Pages 87-95
نویسندگان
Yoshitaka Aizawa, Akira Yoneda,