【作者】 胡宗军；

【导师】 白嘉楠； 李和平；

【作者基本信息】 合肥工业大学 ， 固体力学， 2002， 硕士

【摘要】 糜棱岩是一种动力变质岩，其独特的形成机制使其成为一种具有丰富地质信息的载体。糜棱岩研究在理论和实践上都具有重要意义，对其观测研究越来越受到地质界学者的广泛关注。 针对糜棱岩成因研究中的一些难以解释的现象，本文根据文献[40]的多孔介质模型，建立了糜棱岩原岩的细观损伤力学的体胞单元。认为糜棱岩是原岩韧性孔洞损伤后脆性破碎的结果。本文还对体胞单元进行了有限元计算，并应用莫尔——库仑破碎准则对计算结果进行分析。分析发现：在糜棱岩的产出条件下多孔介质破碎是完全可能的，其中构造剪应力是影响破碎的主要因素，围压是影响原岩塑性行为的主要因素。 根据计算结果解释了糜棱岩中的一系列地质现象，如：塑脆变形特征、晶粒细化、流变构造、带状产出等。应用原岩韧性孔洞损伤模型还解释了超糜棱岩、糜棱岩和初糜棱岩显微结构和构造中的巨大差异现象。 文章最后在有限元计算结果基础上对糜棱岩晶粒细化现象作了半定量分析，对糜棱岩中残晶比例进行了计算，并对计算结果与显微观测的差异做出了解释。更多还原

【Abstract】 Mylonite is a kind of dynamometamorphic rock. Its’ particular formation mechanism makes itself a carrier of rich geology information. The study and research of mylonite is significant not only in theory but also in practice. Many geology scholars are being absorbed in observing and investigating it.Aimed at some bewildering phenomena of mylonite formation study, this thesis theorizes the meso-damage mechanical RVE (representative volume element). of mylonite parent rock according to the porous media which are put forward in literature [40]. Mylonite is thought as the result of mylonite parent rock’s brittle crush after it is porosity damaged plastically. RVE is calculated with the finite element method and the Mohr-Coulomb damage rules are employed to analyse the calculation result. It is fined that the porous media’s crush is completely possible on the condition that mylonite is formed and that the tectonic stress is the major factor but the confining is the minor factor on porous media’s crush.Based on the result, a series geology phenomena are explained such as plastic and brittle distortion, plastic flow structure, strip-shaped output and so on. The great difference of micro-texture among ultramylonite, mylonite and early mylonite can be well explained in this thesis.Crystal diminish phenomenon is given a half quantitative analysis at the end of the thesis. The proportion of porphyroclast in mylonite micro-texture is also calculated and the explanation of the difference between the final result and the micro-observation is presented.更多还原