Flow Laws for Quartzo-Feldspathic Aggregates

PIS将对石英和长石的单相和多相集合体的位错和扩散蠕变的流动规律进行实验测定，这可以可靠地外推到地壳条件。这项研究的一个关键因素将是使用Green和Borch(1989)最近开发的熔盐样品组件，该组件为气体仪器的应力敏感性提供了诱导石英和长石中位错蠕变所需的高压实验的能力。他们将通过在气体装置中对长石中的扩散蠕变进行重复实验来检查这种组件。这项研究的其他主要特点是：(1)确定了石英集合体中位错攀升和蠕变的fH2O(H+)依赖关系，这应该允许人们在将流动规律外推到自然中考虑到先前观察到的水解性减弱的压力依赖关系，以及(2)描述了石英中不同位错蠕变机制占主导地位的条件，以及确保每种机制处于力学稳定状态所需的实验材料和条件。

The PIs will carry out an experimental determination of flow laws for dislocation and diffusion creep of mono- and polyphase aggregates of quartz of and feldspar which can be reliably extrapolated to crustal conditions. A key element of this study will be use of the molten salt sample assembly developed recently by Green and Borch (1989), which provides the stress sensitivity of a gas apparatus with the capability for high pressure experiments required to induce dislocation creep in quartz and feldspar. They will check this assembly by doing duplicate experiments, on diffusion creep in feldspars, in a gas apparatus. Additional key features of the study are (1) a determination of the fH2O (H+) dependence of dislocation climb and creep in quartz aggregates, which should allow one to take account of the previously observed pressure dependence of hydrolytic weakening in extrapolating flow laws to nature, and (2) delineation of the conditions where different regimes of dislocation creep in quartz are dominant and the experimental materials and conditions necessary to ensure mechanical steady state in each.