Dislocation microstructures in majorite garnet ex
- journal_title：American Mineralogist
- Contributor：Hélène Couvy ; Patrick Cordier ; Jiuhua Chen
- Publisher：Mineralogical Society of America
- Date：2011-
- Format：text/html
- Language：en
- Identifier：10.2138/am.2011.3671
- journal_abbrev：American Mineralogist
- issn：0003-004X
- volume：96
- issue：4
- firstpage：549
- section：Articles
摘要
Majorite garnets with the composition Mj70Py30 have been deformed in the multi-anvil apparatus at 17 GPa and 2000 °C. The microstructure has been characterized by transmission electron microscopy. It is shown that under these conditions majorite garnet is ductile. Dislocations with <100> and ½<111> Burgers vectors are observed with a density 1–5 × 1012 m−2. The absence of clear glide planes and the occurrence of subgrain boundaries suggest the importance of diffusion and climb in the plasticity of majorite garnets in mantle transition zone conditions.