松辽盆地南缘基性岩脉中捕获锆石U-Pb年龄及其对基底岩浆事件的制约

发布时间：2018-05-31 13:19

本文选题：松辽盆地 + 基性脉岩　；参考：《岩石学报》2016年09期

【摘要】：团山子基性脉岩为松辽盆地南缘晚中生代最后一期岩浆活动,在其中获得了较多的捕获锆石。为了反映松辽盆地基底岩浆活动事件,对基性脉岩中捕获锆石进行了锆石LA-ICP-MS U-Pb定年。捕获锆石阴极发光(CL)图像和Th/U比值显示具有岩浆成因的特点。从锆石定年结果得到8组年龄,反映出早侏罗世晚期(176Ma)、海西期(291Ma)、加里东期(467Ma)、新元古代(942Ma)、中元古代(1368Ma)、古元古代(1886Ma和2165Ma)、新太古代(2458Ma)岩浆事件记录。松辽盆地南部基底组成以古生代和早中生代岩浆岩为主,并可能存在西保安群前寒武纪结晶基底(942Ma),并经历了复杂的岩浆演化。中元古代、古元古代、新太古代年龄的锆石具有磨圆和反应边,可能为与华北克拉通岩浆事件形成的锆石被搬运到松辽盆地南部,并被再次捕获的结果,反映松辽盆地南部与华北大陆具有一定的联系,但不确定存在该期的结晶基底。
[Abstract]:Tuanshanzi basic dike rock is the last late Mesozoic magmatic activity in the southern margin of Songliao Basin, in which more zircon traps have been obtained. In order to reflect the event of magmatic activity in the basement of Songliao Basin, zircon LA-ICP-MS U-Pb dating was carried out for the capture of zircon from the basic dike rocks. The captured zircon cathodoluminescence (CLL) images and Th/U ratios show magmatic genesis. Eight ages were obtained from zircon dating, reflecting the records of magmatic events in late early Jurassic, Hercynian, Caledonian, Neoproterozoic, Neoproterozoic, Mesoproterozoic, Paleoproterozoic, and NeoArchean, respectively. The basement composition of the southern Songliao Basin is mainly Paleozoic and early Mesozoic magmatic rocks, and there may be Precambrian crystalline basement of Xianan Group, which has undergone complex magmatic evolution. The zircon of Mesoproterozoic, Paleoproterozoic and NeoArchean ages has a round and reactive edge, which may be the result of the zircon formed by the North China Craton magma event being transported to the south of Songliao Basin and captured again. It shows that the southern part of Songliao Basin is related to the North China continent to some extent, but it is uncertain that the crystalline basement exists in this period.
【作者单位】：吉林大学地球科学学院;吉林大学地球探测科学与技术学院;桂林理工大学地球科学学院;
【基金】：国家自然科学基金项目(40973019) 中国地质调查局项目(科[2012]D2-02,1212010911084)联合资助
【分类号】：P588.1;P597

【相似文献】