北大别穹隆变形组构一期或多期形成:来自韧性变形组构叠加数值模拟的证据  

Superimposition of Fabrics in North Dabie Dome: Constraints of Numerical Modeling

作　　者：高丽敏 向必伟[1] 程泓 徐晨 孔令竹 王润芳 李媛 GAO Limin;XIANG Biwei;CHENG Hong;XU Chen;KONG Lingzhu;WANG Runfang;LI Yuan(School of Resources and Environmental Engineering,Anhui University,Hefei 230601,Anhui,China)

机构地区：[1]安徽大学资源与环境工程学院,安徽合肥230601

出　　处：《大地构造与成矿学》2018年第4期602-611,共10页Geotectonica et Metallogenia

基　　金：国家自然科学基金资助项目(41472194;41002069)资助

摘　　要：矿物拉伸线理和面理是研究岩石韧性变形运动学的基本要素。然而自然界许多应变带内拉伸线理和面理产状分布往往并不单一。如何正确认识这类变形组构,并利用这些组构开展构造变形分析至今仍备受争议。本文基于Eshelby理论,通过数值模拟,研究了岩石经历两期不同韧性变形后面理和拉伸线理的产状特征。模拟结果显示岩石经历两期构造变形时,岩石中的较软矿物仅能保留下最后一期构造变形运动学信息。这一认识得到了北大别穹隆内变形组构的支持。北大别穹隆内产状复杂的拉伸线理只记录了造山后伸展期变形。本次数值模拟结果对野外构造观察和分析以及确定构造变形时间具有指导意义。Mineral stretching lineations and foliations are the basic kinematic factors of ductile deformation.However,the actual stretching lineations and foliations are usually inconsistent.Interpretation of these lineations and foliations is still controversial.In this paper we modeled numerically the lineations and foliations produced in two successive flowing fields.Our modeling demonstrates that the lineations defined by the softer minerals can only keep the kinematic information of the last structural deformation.Our modeling results indicate that the lineations and foliations of the North Dabie dome only recorded the post-orogenic extensional deformation.

关 键 词：叠加组构 数值模拟 流变场 韧性变形 大别造山带 

分 类 号：P542[天文地球—构造地质学]