最上部マントルかんらん岩の結晶方位ファブリックとP波速度構造 [in Japanese] Olivine Crystallographic Fabrics and Their P-wave Velocity Structures within Peridotites in the Uppermost Mantle [in Japanese]
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Olivine crystal grains have various crystallographic orientations within a peridotite, resulting in a crystallographic fabric as well as a texture. Six types of fabrics have been identified in mantle peridotites: A, B, C, D, E and AG types. These fabric types have unique seismic properties such as P-wave and S-wave velocity anisotropy. A new method is proposed to classify olivine fabrics based on P-wave velocity structure on a Vp-Flinn diagram. Three P-wave velocities (<i>V<sub>1</sub></i>, <i>V<sub>2</sub></i>, <i>V<sub>3</sub></i>) are used, two of which are the maximum (<i>V<sub>1</sub></i>) and minimum (<i>V<sub>3</sub></i>) velocities, and the third (<i>V<sub>2</sub></i>) is the velocity perpendicular to the orientations of these two velocities. Relationships between <i>V<sub>1</sub></i>/<i>V<sub>2</sub></i> and <i>V<sub>2</sub></i>/<i>V<sub>3</sub></i> classify fabrics into three types: A type (equivalent to B, C and E types), D type and AG type. Moreover, taking into account structural framework such as foliation and lineation, the Vp-Flinn diagram can be expanded to identify all types of fabrics. This method is successfully applied to fabrics previously studied in Oman ophiolite.
- Journal of Geography (Chigaku Zasshi)
Journal of Geography (Chigaku Zasshi) 124(3), 397-409, 2015
Tokyo Geographical Society