松辽盆地西缘边界断裂带中北段尼尔基L型构造岩构造年代学及其构造意义  

Chronology of L-Type tectonite from Nierji area in the northern-middle segment of the western boundary fault of the Songliao Basin and its tectonic implications

作　　者：韩国卿[1,2,3] 刘永江[1] Franz NEUBAUER Johann GENSER 梁琛岳[1,3] 温泉波[1] 赵英利[1,4] 

机构地区：[1]吉林大学地球科学学院,长春130061 [2]西北大学大陆动力学重点实验室,西安710069 [3]萨尔茨堡大学地质地理系 [4]吉林大学古生物学与地层学研究中心,长春130061

出　　处：《岩石学报》2014年第7期1922-1934,共13页Acta Petrologica Sinica

基　　金：国家"973"项目(2013CB429802);国家自然科学基金重点项目(41302163;41230206);吉林大学基本科研业务经费(450060491393);中国博士后基金面上项目(2013M540244);国家留学基金建设高水平大学公派研究生项目(2008617114);西北大学大陆动力学国家重点实验室开放课题基金联合资助

摘　　要：松辽盆地西缘与大兴安岭东缘的边界断裂带,又称嫩江-八里罕断裂带,位于东北地区中部,中亚造山带东段。断裂带呈NNE走向,沿内蒙古自治区、黑龙江省与吉林省的交界,一直向南延伸至河北省境内与平场-桑园大断裂相接,全长1200km。该断裂带传统认识上被认为是一条NNE向的大型正断层或拆离断层。目前对于断裂带性质的研究主要集中在其北段的嫩江断裂,但侧重区域地球物理方面,通过布格重力异常、航磁异常、深反射剖面研究确定了断裂带的走向、展布位置,及伸展拆离断层或大型低角度正断层的性质;其南段断裂带（红山-八里罕断裂）的研究,主要与喀喇沁隆起的形成时间、性质、演化阶段等方面相联系;然而对断裂带中段的嫩江-八里罕断裂的研究少有报道。近期,我们报导了嫩江-白令海断裂带岭下及白城地区发现的具有左旋走滑性质的韧性剪切带,并同断裂带南段的红山-八里罕断裂带楼子店地区进行系统的对比。通过对岭下地区韧性剪切带详细的野外调查、构造要素测量、显微构造研究、同构造变形岩石的有限应变分析、石英EBSD组构分析以及白云母40Ar/39Ar年代学研究,我们认为岭下韧性剪切带与楼子店韧性剪切带的变形特征一致,证实了红山-八里罕断裂带至少可以向北延伸至中段岭下地区,其性质同为左行走滑韧性剪切带,并具有相同的早期走滑时限（~130Ma）。本次,我们进一步对嫩江-白令海断裂带中北段尼尔基地区韧性剪切带进行研究,通过对带内韧性变形岩石构造要素系统测量和统计、显微构造观察、有限应变测量等方面的研究,表明其岩石类型属L型构造岩,具左行剪切特征。综合分析发现除构造岩的类型（岭下与楼子店地区发育S-L型构造岩）,其余与岭下与楼子店地区韧性剪切带性质相同。另外,年代学表明L型花岗质岩石中发育的锆As the western boundary fault of the Songliao Basin and the eastern margin of the Da Xing＇ an Mountains, Nenjiang- Balihan Fault Beh is located in the central part of northeastern China, the eastern segment of the Central Asian Orogenic Belt. It extends along the boundary between the Heilongjiang and Jilin provinces, and the Inner Mongolia Autonomous Region, with the NNE striking, and then goes into the Hebei Province to the south, connecting with the Pingchang-Sangyuan Fault, with a total length over 1200km. The Nenjiang-Balihan Fault Belt is considered traditionally to be a huge deep-seated fauh, and characterized by a normal fault or detachment fault. So far, some regional geophysical research on this fault zone is focused on its northern segment, the Nenjiang Fault, including the bouguer gravity anomaly, the aeromagnetic anomaly, and the deep reflection seismic profile, which revealed the regional distribution of the Nenjiang Fault System and indicated that Nenjiang Fault System should be a huge low-angle normal fault or detachment fault. In the southern segment of this fault belt, it is called the Hongshan-Balihan Fault, which has been studied as the eastern margin detachment fault of the Kalaqin （Harkin） Uplift. The study on the middle part of the Nenjiang-Balihan Fault Belt is rare. We newly found a S-L typed ductile shear zone at the Lingxia, Baicheng City, the middle-southern part of the Nenjiang-Balihan Fault belt, and compared this ductile shear zone with that at the Louzidian area, in the southern part of the Nenjiang-Balihan Fault belt. Based on the field investigation, measurements of structures in the field, micro-structural studies, finite strain measurements, a study on preferred crystal orientations of quartz determined by Electron Back Scatter Diffraction and muscovite 40Ar/39Ar chronology of the deformed rocks in the ductile shear zone, we suggested that the deformation features of the Lingxia and Louzidian ductile shear zones are similar, and that they represent one continuous fault, i.

关 键 词：L构造岩 左行剪切 尼尔基地区 松辽盆地 松辽盆地西缘边界断裂带 

分 类 号：P542[天文地球—构造地质学] P597.3[天文地球—地质学]