Synthesis and high-temperature deformation experiments on polycrystalline Fe-bearing olivine

Abstract

Experimental results of high-temperature creep of polycrystalline Fe-bearing olivine have been used to understand the upper mantle rheology. In this study, we synthesized Fe-bearing olivine (Mg_1.8Fe_0.2SiO₄) aggregate by using a new method and investigated the effect of impurities on the strength of olivine aggregate. Deformation tests on doped 0.1wt% Al₂O₃, CaO, NiO, TiO₂, or both Al₂O₃ and CaO) samples showed no major difference in their strength under diffusion creep. Further, we found that Fe-bearing aggregate exhibited one order of magnitude lower strength compared to Fe-free olivine aggregate.