华北南缘古元古代末岩墙群侵位的磁组构证据  

Magnetic fabric evidences for the Late Paleoproterozoic mafic dyke swarm emplacement,southern margin of the North China craton

作　　者：侯贵廷[1] 王传成[1] 李乐[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

出　　处：《岩石学报》2010年第1期318-324,共7页Acta Petrologica Sinica

基　　金：国家973项目(2009CB219302);国家自然科学基金面上项目(40172066;40314141及40772121)资助

摘　　要：华北克拉通南缘的中条山及邻区广泛发育元古宙放射状基性岩墙群,与五台山-恒山和大同地区的北北西向基性岩墙群以及熊耳中条拗拉谷的火山岩在时空分布和地球化学方面均具有密切的相关性。中条山及邻区放射状基性岩墙群的宏观和微观流动构造(包括捕虏体、冲痕构造、矿物线理和定向斑晶)指示岩墙群以一定的仰角向北西侵位。通过该区岩墙群磁化率各向异性(AMS)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华北南缘古元古代末岩墙群从熊耳中条拗拉谷的底部向北西侵位。岩墙群的流动构造和磁组构的统计成果夯实了华北克拉通古元古代末基性岩墙群与熊耳中条拗拉谷的成生联系。In the time-space and geochemistry,the radiating Proterozoic mafic dyke swarms in the Mt.Zhongtiao are related to the mafic dyke swarms in the Mt.Wutai-Hengshan,and both of the mafic dyke swarms are related to the Xiong' er volcanic rocks in the Xiong' er-Zhongtiao aulacogen.The macro and micro flow structures(including xenolithes,scours,mineral lineations and orientation of phenocrystals) in the radiating mafic dyke swarms of the Mt.Zhongtiao indicate that the mafic dyke swarm emplaced from SE to NW at an angle.Based on measurement of the anisotropy of magnetic susceptibility(AMS),the dominant orientations of the maximum magnetic susceptilbility and analysis of susceptibility characteristics also indicate that the mafic dyke swarm emplaced from SE to NW from the bottom of the Xiong'er-Zhongtiao aulacogen,and further support that the Late Paleoproterozoic mafic dyke swarms in the North China craton are much related to the Xiong' er-Zhongtiao aulacogen.

关 键 词：华北克拉通 基性岩墙群 流动构造 磁组构 侵位机制 

分 类 号：P584[天文地球—岩石学]