阿尔金北缘岩石变形机制——来自X光组构分析的证据  

Rock deformation mechanism of northern Altun margin—Evidence from X-ray fabric analysis

作　　者：何江涛[1,2] 陈柏林[2] 王永[2] 孟令通[2] 吴玉[2] 韩梅梅[1,2] 王斌[1] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国地质科学院地质力学研究所,北京100081

出　　处：《地质通报》2016年第1期123-129,共7页Geological Bulletin of China

基　　金："十一五";"十二五"国家科技支撑计划重点项目(编号:2006BAB07B02-04;2011BAB06B08-04);中国地质调查局项目(编号:1212011085043);国家自然科学基金项目(批准号:41502086)

摘　　要：对阿尔金北缘地区变形蚀变花岗岩、花岗质糜棱岩、变形酸性火山岩和变形英安质凝灰岩中石英和绢云母2种矿物进行X光岩石组构分析,认为本区岩石变形比较明显,宏观面理近于东西向展布,绢云母变形较强,平行于面理定向排列;而石英以底面或近底面滑移为主,部分样品兼有柱面Ⅰ型滑移和柱面Ⅱ型滑移,反映本区岩石变形机制为中浅层次的脆-韧性变形（10~15km、250~350℃、0.25~0.40GPa）。通过岩石组构特征与宏观面理产状,推断本区韧性变形以右行运动为主,与板块碰撞在阿尔金北缘大平沟地区产生的韧性变形带特征一致。This paper reports the geological tectonic settings and regional stratigraphic rocks of northern Altun marginal area. Based on the quartz and sericite X-ray perofabrics analysis of altered deformed granite, granitic mylotite, deformed acidic volcanic rock and deformed dacitic tufffrom this area, the authors have drawn the following conclusions： ①The rock deformation of this area is relatively apparent; ②Sericite is parallel to the schistosity and shows a great orientation in the alignment which reflects the strong deformation along the EW-trending tectonic deformed belt; ③Quartz is mainly deformed along its basal or basal-near glide system and is combined with prismatic I and 1I glide system; ④The deformation mechanism of northern Altun area happened at a medium-shal- low depth of 10-15km with a low-middle temperature of 250-350℃ and a low pressure of 0.25-0.40GPa;According to the fea- tures of X-ray perofabrics analysis and schistosity, the authors hold that this ductile deformation moved in a right-lateral way. All this is consistent with the features of ductile-britde deformation zone formed by plate collision belt and oceanic crust closure in Dapinggou area of northern Altun.

关 键 词：X光衍射 组构分析 变形机制 阿尔金北缘 

分 类 号：P583[天文地球—岩石学] P588.1[天文地球—地质学]