标题： 橄榄石在上地幔条件下的粒生长压力依赖性 显示英文标题

标题： Pressure dependence of olivine grain growth at upper mantle conditions

摘要： 橄榄石的粒度影响地球软流圈的物质和热通量。我们在1至12 GPa和1323至1793 K条件下对合成橄榄石-辉石混合物（体积分数6%-13%）进行了退火实验。通过电子背散射衍射（EBSD）分析粒度，得到一个激活体积为$4.8 \times 10^{-6}\ \mathrm{m}^3/\mathrm{mol}$，与硅的晶界扩散值相匹配。 这表明压力驱动下橄榄石生长速率的降低可能会抵消深部温度的影响，在比之前模型预测的更浅的软流圈深度上实现粒度敏感型蠕变。 显示英文摘要

摘要： The grain size of olivine influences mass and heat flux in Earth's upper mantle. We performed annealing experiments on synthetic olivine-pyroxene aggregates (6-13 vol.%) at 1-12 GPa and 1323-1793 K. Grain-size analysis via EBSD reveal an activation volume of $4.8 \times 10^{-6}\ \mathrm{m}^3/\mathrm{mol}$, matching silicon grain-boundary diffusion values. This suggests pressure-driven reduction in olivine growth rates may offset temperature effects at depth, enabling grain-size-sensitive creep at shallower mantle depths than previously modeled.