Experimental logs and analysis of olivine polymorphs and MORB (Mid-Ocean Ridge Basalt) composition garnetite samples recovered from high-pressure faulting experiments

Multi-anvil experiments were performed both in static and deformation geometries on olivine polymorphs and MORB (Mid-Ocean Ridge Basalt) -composition garnetite. Faults were induced by uniaxial compression in both garnetite and wadsleyite but only the garnetite showed evidence of thermal run away to melting. These results suggest that strain localisation by thermal feedback might be an important mechanism for triggering deep earthquakes in the crustal portion of subducted slabs in the deeper transition zone (~500-660 km depth).

针对橄榄石同质多象变体以及洋中脊玄武岩（Mid-Ocean Ridge Basalt，简称MORB）组分石榴子岩，分别采用静态几何构型与变形几何构型开展多砧实验。通过单轴压缩实验，在石榴子岩与瓦兹利石（wadsleyite）中均诱导出断裂构造，但仅石榴子岩观测到热失控熔融的迹象。上述实验结果表明，由热反馈驱动的应变局域化，或许是触发深部过渡带（约500~660千米深度）俯冲板片地壳段深源地震的重要机制。