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中生代发生在东北亚地区的蒙古-鄂霍次克造山作用一直是国内外地学界十分关注的大地构造事件.综合利用油气勘探新获取的地震反射、钻井、测井等资料,在海拉尔盆地贝尔凹陷早白垩世断陷层序之下识别出一套卷入强烈挤压变形的构造层.构造解析表明它主要由一条北东东向的逆掩断层及其相关的冲断-褶皱变形系统构成.地层岩性特征和碎屑锆石U-Pb测年结果显示,这是一套沉积于晚侏罗世末期的陆相湖盆碎屑岩建造,区域上应归属上侏罗统塔木兰沟组;结合上覆早白垩世断陷盆地的发育和邻区同期变质核杂岩体隆升剥露时代,提出海拉尔盆地这期冲断-褶皱变形事件发生在早白垩世早期(ca.145~133Ma),是晚中生代蒙古-鄂霍次克洋闭合后进入强烈陆内造山作用的构造变形记录.
The Mesozoic-Okhotsk orogeny in Mesozoic has always been a tectonic event that is of great concern to the geoscience community at home and abroad. Comprehensive utilization of newly acquired seismic reflection, drilling and well logging data in the early Belle sag of the Hailar Basin A Cretaceous fault sequence identifies a tectonic layer that is trapped in intense crustal deformation.The tectonic interpretation shows that it is mainly composed of an NE-trending inverse fault and its associated thrust-fold deformation system. Lithological features and detrital zircon U-Pb dating show that this is a set of continental lacustrine clastic sediments that were deposited in the late Jurassic and should belong to the Upper Jurassic Tamulang Formation in the area During the Early Cretaceous rifting basin and the uplifting and exhumation of the metamorphic core complex in the adjacent area, it was proposed that the thrustfold deformation event in the Hailar Basin occurred in the early Cretaceous (ca.145 ~ 133Ma) Tectonic deformation records of late Mesozoic Mongolian-Okhotsk Ocean closure into orogeny after intracontinental orogeny.