Deformation Mechanisms, Microstructures, and Flow Laws for Quartzo-Feldspathic Aggregates

本研究将探讨石英长石的变形机制，以提高我们对地壳变形历史的认识，并促进在不同构造环境下应力水平和染色划分的准确建模。调查人员将进行3个研究项目。首先，他们将完成先前在石英中确定的3种再结晶机制和相应的位错蠕变机制的再结晶晶粒尺寸压力表的实验校准，并将在跨越所有3种机制的宽温度范围的自然剪切区应用它们进行测试。其次，他们将完成一项实验研究，通过该过程，石英长石骨料中相对少量的弱云母相互连接和分散，导致深刻的应变减弱和局部化到韧性剪切带。第三，完成斜长石固溶体系列变形机制和强度变化的侦察实验研究。在此基础上，研究人员将选择2或3个关键成分进行熔盐组件的进一步步进实验，以确定流动规律参数。

Tullis0106859This research will investigate deformation mechanisms in quartzo-feldspathic rocks with the aim of enhancing our understanding of deformation history of the crust as well as to facilitate accurate modeling of the stress levels and stain partitioning in different tectonic settings. The investigators will work on 3 research projects. First they will complete an experimental calibration of the recrystallized grain size piezometer for the 3 recrystallization mechanisms and corresponding dislocation creep regimes previously identified in quartz, and will test them with application to a natural shear zone which spanned a wide temperature range including all 3 regimes. Second, they will complete an experimental study of the processes by which a relatively small amount of weak mica in a quartza-feldspathic aggregate becomes interconnected and dispersed, leading to profound strain weakening and localization into ductile shear zones. Third, they will complete a reconnaissance experimental study of the variation in deformation mechanisms and strength across the plagioclase solid solution series. Based on that study the investigators will choose 2 or 3 key compositions for further stepping experiments in a molten salt assembly to determine flow law parameters.