日時 ： ２００９年１２月４日（金）※16：30～
場所 ： 愛媛大学総合研究棟Ⅰ 4F 共通会議室（理学部構内）
要 旨
Knowledge of rheological properties of deep Earth materials is important for understanding the dynamics of the Earth's interiors. Among the upper mantle minerals, olivine is the most abundant phase and is considered to be the weakest phase, with the lowest viscosity. Therefore, the rheology of the upper mantle is most probably dominated by that of olivine. Many experimental studies have been conducted to understand rheology of olivine, and the influence of many factors, such as stress, temperature, grain-size, water fugacity, on olivine rheology have been determined quantitatively. However, since most of the previous rheological studies have been conducted at relatively low pressures, effect of pressure on olivine rheology is still under debate. The reported values of activation volume for power-law creep based on recent high-pressure deformation experiments of olivine using D-DIA and RDA are scattered. There is no general consensus about the transition of lattice preferred orientation in the Earth's upper mantle condition. In this seminar, I review recent studies on high-pressure olivine rheology, including the stress relaxation test conducted by ourselves, and discuss problems to be solved.
問い合わせ先：土屋 卓久 TEL （089）927-8198
E-mail takut@sci.ehime-u.ac.jp
