新疆克拉玛依北西西向岩墙群侵位的磁组构证据  

Magnetic Fabric Evidence for the Emplacement of Karamay NWW Dyke Swarm , Xinjiang

作　　者：李乐[1,2] 侯贵廷[1,3] 杨彦平 肖芳锋[1] 王延欣[1] 

机构地区：[1]教育部造山带与地壳演化重点实验室,北京大学地球与空间科学学院,北京100871 [2]新兴铸管股份有限公司,新兴际华集团有限公司,北京100020 [3]北京大学石油与天然气研究中心,北京100871

出　　处：《地质学报》2013年第6期814-822,共9页Acta Geologica Sinica

基　　金：国家973项目(编号2009CB219302);国家自然科学基金项目(编号40772121)资助的成果

摘　　要：准噶尔盆地西北缘克拉玛依地区广泛发育二叠纪中基性岩墙群,该区岩墙被认为是碰撞后伸展的典型产物。本文根据岩墙宏观野外特征和镜下显微构造分析(岩墙分支、捕虏体、矿物线理和定向斑晶)得出研究区北西西—南东东向岩墙侵位方向由北西西向南东东侵位。通过对该区岩墙边界采样后进行磁化率各向异性测量得到磁组构的最大磁化率长轴优势方位分布图和磁组构各向异性特征分析,进一步指示其岩浆以一定仰角由北西西向南东东侵位。结合克拉玛依地区岩墙群与达拉布特深大断裂的时空分布特征推测该区北西西向岩墙岩浆来源于北西侧的达拉布特断裂,岩浆沿着达拉布特深大断裂上侵到先存裂隙而形成岩墙。The mafic-intermediate Permian dykes widely spread in parallel around the Karamay region , northwestern Junggar , are considered as a typical product of late-collision tension.Based on outcrop features and microscope observation , including the dyke branches , oriental xenolith , mineral lineation and oriental porphyrotope , this study concludes that NWW-SEE dykes emplaced from west to east.The measurement of the anisotropy of magnetic susceptibility （ AMS ）, the dominant orientations of the maximum magnetic susceptibility and analysis of susceptibility characteristics also indicate that the mafic dyke swarm emplaced from NWW to SEE.Combined with the space-time distribution characteristics of Dalabute fault , the results shows that the magma transported through the deep fault system of Dalabute to the subsurface and emplaced into the pre-exist fractures system to form dyke swarms.

关 键 词：岩墙群 流动构造 磁组构 侵位机制 新疆克拉玛依 

分 类 号：P548[天文地球—构造地质学]