Quantitative study of microstructures and microtextures of Ol-Diogenites (Harzburgites and Dunites). Eyewitnesses of early mantle processes in Vesta-like asteroids

老第长岩（Harzburgites 和 Dunites）微观结构和微观纹理的定量研究。

• 批准号: 248756347
• 负责人: Professor Dr. Frank Erich Brenker
• 金额: --
• 依托单位: Abteilung Petrologie und Geochemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/248756347?language=en
• 关键词: Quantitative; study; microstructures; microtextures; Ol

Based on our unpredicted finding of solid state plastic deformation via pencil glide during our preliminary work on the harzburgitic diogenite NWA 5480, which will have several far reaching consequences on the thermal history, chemical and structural equilibration in the early stages of asteroid formation, we propose to perform a comprehensive quantitative structural and textural study of olivine-rich diogenites (harzburgites and dunites) which most likely represent mantle rocks originated from the differentiated Vesta or a Vesta-type asteroid.For the first time a characterization and quantification of the complete micro and nano structural inventory of this rare rock type will be performed. This enables to unravel details of the thermal and structural evolution and some cases the effective deformation mechanism. A combination of electron backscatter diffraction (EBSD) and large area transmission electron microscopic (TEM) will be applied in order to measure details of the crystallographic preferred orientation and relate them to texture forming processes like crystallization, compaction, shock effects and deformation mechanism. In the broader framework of NASAs Dawn mission to Vesta this study will help to better understand the formation mechanism and evolution of differentiated asteroids.

基于我们在对方斜角闪长岩 NWA 5480 进行初步研究期间通过铅笔滑移意外发现的固态塑性变形，这将对小行星形成早期阶段的热历史、化学和结构平衡产生几个深远的影响，我们建议对富含橄榄石的闪长岩（方辉橄榄岩和纯橄榄岩）进行全面的定量结构和结构研究，这些闪长岩很可能代表源自分化的灶神星或灶神星的地幔岩石灶神星型小行星。将首次对这种罕见岩石类型的完整微米和纳米结构清单进行表征和量化。这使得能够揭示热和结构演化的细节以及某些情况下的有效变形机制。将应用电子背散射衍射 (EBSD) 和大面积透射电子显微镜 (TEM) 的组合来测量晶体择优取向的细节，并将其与结晶、压实、冲击效应和变形机制等织构形成过程联系起来。在美国宇航局黎明号灶神星任务的更广泛框架中，这项研究将有助于更好地了解分化小行星的形成机制和演化。