The Effect of Intracrystalline Water on the Mechanical Properties of Olivine at Room Temperature
The Effect of Intracrystalline Water on the Mechanical Properties of Olivine at Room Temperature
复制标题
室温下结晶水对橄榄石力学性能的影响
DOI：
10.1029/2023gl106325
复制
发表时间：
2024
影响因子：
5.2
通讯作者：
Wilkinson, Angus J.
中科院分区：
文献类型：
--
作者：
Kumamoto, Kathryn M.;Hansen, Lars N.;Breithaupt, Thomas;Wallis, David;Li, Bo‐Shiuan;Armstrong, David E. J.;Goldsby, David L.;Li, Yang;Warren, Jessica M.;Wilkinson, Angus J.
小浓度的晶内水对橄榄石强度的影响是显着的软流圈温度，但在较低的温度适用于浅岩石圈约束不佳。我们研究了水对橄榄石在低温塑性过程中屈服应力的影响，使用室温Berkovich纳米压痕。在不确定性范围内，橄榄石（1，600 ppm H/Si）中存在水不会影响相对于干燥橄榄石（≤40 ppm H/Si）的硬度或屈服应力，但可能会略微降低杨氏模量。与不同取向的干燥晶体之间的差异相比，相似取向的含水晶体和干燥晶体之间的差异较小。这些观察结果表明，在低同源温度下，水含量不影响橄榄石的强度。因此，在这些温度下，晶内水在橄榄石变形中不起作用，这意味着水不会导致地幔最冷部分的弱化。
The effect of small concentrations of intracrystalline water on the strength of olivine is significant at asthenospheric temperatures but is poorly constrained at lower temperatures applicable to the shallow lithosphere. We examined the effect of water on the yield stress of olivine during low‐temperature plasticity using room‐temperature Berkovich nanoindentation. The presence of water in olivine (1,600 ppm H/Si) does not affect hardness or yield stress relative to dry olivine (≤40 ppm H/Si) outside of uncertainty but may slightly reduce Young’s modulus. Differences between water‐bearing and dry crystals in similar orientations were minor compared to differences between dry crystals in different orientations. These observations suggest water content does not affect the strength of olivine at low homologous temperatures. Thus, intracrystalline water does not play a role in olivine deformation at these temperatures, implying that water does not lead to weakening in the coldest portions of the mantle.