کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6447568 1641508 2014 46 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structure and elasticity of phlogopite under compression: Geophysical implications
ترجمه فارسی عنوان
ساختار و کشش فلوگوپیت تحت فشرده سازی: پیامدهای ژئوفیزیکی
کلمات کلیدی
قابلیت ارتجاعی، آنیزوتروپیک لرزه ای، فازهای هیدرولیکی، منطقه فرونشانی،
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فیزیک زمین (ژئو فیزیک)
چکیده انگلیسی
We investigated the response of the crystal structure, lattice parameters, and unit-cell volume of hydrous layered silicate phlogopite at conditions relevant to subduction zone settings. We have used first principles simulation based on density functional theory to calculate the equation of state and full elastic constant tensor. Based on the generalized gradient approximation, the full single crystal elastic constant tensor with monoclinic symmetry shows significant anisotropy with the compressional elastic constants: c11 = 181 GPa, c22 = 185 GPa, c33 = 62 GPa, the shear elastic constants c44 = 14 GPa, c55 = 20 GPa, c66 = 68 Ga, and c46 = −6 GPa; the off diagonal elastic constants c12 = 48 GPa, c13 = 12 GPa, c23 = 12 GPa, c15 = −16 GPa, c25 = −5 GPa and c35 = −1 GPa at zero pressure. The elastic anisotropy of phlogopite is larger than most of the layered hydrous phases relevant in the subduction zone conditions. The shear anisotropy, AVS for phlogopite is ∼77% at zero pressure condition and although it decreases upon compression it remains relatively high compared to other hydrous phases relevant in the subduction zone settings. We also note that the shear elastic constants for phlogopite are relatively low. Phlogopite also has a high isotropic bulk VP/VS ratio ∼2.0. However, the VP/VS ratio also exhibits significant anisotropy with values as low as 1.49. Thus, phlogopite bearing metasomatized mantle could readily explain unusual VP/VS ratio as observed from seismological studies from the mantle wedge regions of the subduction zone.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physics of the Earth and Planetary Interiors - Volume 233, August 2014, Pages 1-12
نویسندگان
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