黑龙江省虎林盆地单元结构的地质-地球物理研究

Study on Geology and Geophysics on Structural Units of Hulin Basin in Heilongjiang Province

采用基于余弦变换的重力异常向上延拓及常密度单界面重力异常反演方法对虎林盆地布格重力异常进行了处理,反演了基底深度。结合穿过盆地的重力和大地电磁测深剖面资料及俄罗斯一侧的阿尔昌盆地的地质资料,分析了虎林盆地地质-地球物理所反映的盆地南部和北部基底结构的差异性。研究结果表明:敦密断裂(由2支断裂组成)中的南支断裂倾向直立,走滑特征明显,控制着其两侧断块的走滑及盆地的形成和演化过程,为主干断裂;以其为分界线,虎林盆地由地质和地球物理性质完全不同的2个盆地(南部盆地和北部盆地)组成,北部盆地为大三江盆地的一部分,南部盆地则属于另外一个独立的盆地体系。

Based on the cosine transform method,and using the method of upward continuation and computed base depth of the basin using the inverse technique of even（density） and single interface,the authors had processed the Hulin basin Bouguer gravity anomalies and inversed the base depth.At the same time,by analyzing integrated interpretation results of gravity and magnetotelluric sounding profile in Hulin basin and neighbouring geologic information in Russia,We studied differences of underlying structure between south and north of the basin reflected by geology and geophysics,and redistricted its structural units.It is shown that the south fracture of Dunmi fault,which was composed of two faults,is vertical and strike-slip fault,it controls strike-slip movement of its bilateral fault block and the formation and evolution of the basin.If let Dunmi south fault as dividing line,the Hulin basin can be divided into two basins,i.e.south basin and north basin,and their geology and geophysics properties are totally different.The north basin is part of large Sanjiang basin,whereas the south basin is an independent basin system.