中国东北大剖面绥化-虎林段构造物理研究及意义

Today, as the geological history of the earth in northeast China as the accretion continent with the evolution of multi- block during split times, fixed in the stress field under the subducting deep Pacific plate to the Eurasian continent, formed the range and basin geomorphology, and therefore its tectonophysics characteristics and tectonic units distribution situation in the deep is the focus of attention in the Earth science community. Based on the research result of the China Geological Survey project, the experimentation of deep probing technologies and integration project (SinoProbe-02) and applicant's previous research, shallow - deep tectonophysics characteristics derived form an east - west nearly 600km length of deep seismic reflection cross-section, which from Suihua, the eastern edge of Songliao Basin, crossing Zhangguangcailing to the Hulin Basin, are the main research contents of this application. The research results from area gallery section of the crust will be referenced, frequency analysis and energy analysis and other methods are going to be applied in single shot gathers record in major tectonic units derived from Suihua - Hulin cross-section, and thus comparative analysis of seismic wave propagation law in different tectonic units inside will be discussed. Experimental methods are going to applied to study the structure of geophysical of this large cross-sectional, such as, first arrive tomographic inversion method to obtain near-surface velocity structure, common reflection surface stack method and time - depth conversion techniques to imaging deep structure, numerical simulation of seismic wave propagation to test velocity structure, the deep seismic reflection profile structure characteristics of seismic to constraints magnetotelluric sounding profile processing. Analyze and summarize the shallow crust and the deep upper mantle structural relationships and characteristics to the eastern margin of the basin-mountain region of Songliao Basin, and then explore and discuss its significances.

现今，中国东北作为多地块、多次拼合的大陆增生区，定型于太平洋板块向欧亚大陆深俯冲的应力场作用，而形成盆、山相间的地貌特征，其深部构造物理特征及构造单元的分布态势是地球科学界关注的焦点。在中国地质调查项目、深部探测技术实验与集成项目和申请者前期研究的基础上，以西起松辽盆地东缘，横过张广才岭，东至虎林盆地东西向长近600km的深反射地震剖面的浅-深构造物理特征为研究内容。参考区域廊带地壳断面的研究成果，通过对绥化-虎林剖面经过的主要构造单元区内炮集记录的时频、能量等方法，对比分析不同构造单元内部的地震波传播规律。应用初至波层析反演近地表速度结构方法、共反射面元叠加成像与时深转换技术、地震波传播数值模拟、深反射地震剖面结构特征约束下的大地电磁剖面处理与成像等实验方法，进行大剖面地球物理构造研究。分析、归纳松辽盆地东缘盆山地区地壳及上地幔的浅-深结构关系与特征，进而探讨其研究意义。

现今，中国东北作为多地块、多次拼合的大陆增生区，定型于太平洋板块向欧亚大陆深俯冲的应力场作用，而形成盆、山相间的地貌特征，其深部构造物理特征及构造单元的分布态势是地球科学界关注的焦点。在中国地质调查项目、深部探测技术实验与集成项目和申请者前期研究的基础上，以西起松辽盆地东缘，横过张广才岭，东至虎林盆地东西向长近600km的深反射地震剖面的浅-深构造物理特征为研究内容。首先，运用近地表层析建模工具，计算了深地震反射数据的初至波走时信息，进行了近地表速度结构层析成像试验研究，刻画出松辽盆地东缘深部断陷盆地的几何特征，发现七台河速度凹陷，虎林盆地及其西北部的速度凹陷值得进一步调查。共反射面元（CRS）技术应用于深地震反射剖面数据，可以有效改善并大大提高道集数据的质量，为后续研究提供高质量、高保真的基础数据。采用层速度约束反演技术，获得较准确的深度域层速度，然后采用了波动方程深度偏移技术进行深度偏移，获得了深度域剖面，为松辽盆地深层莫霍面的深度研究，提供了较好的数据参考。基于深地震反射成像结果的大地电磁测深数据处理的结构研究表明，研究区深部具有“横向分块—纵向分层”的特点，可划分为三个构造单元：松嫩地块东缘、碰撞拼合带和佳木斯地块西缘。电性结构反映的上地幔的西倾高阻体R3，与深地震反射西倾的地幔反射，指示了佳木斯地块向西俯冲到松嫩地块之下的痕迹, 为松辽盆地基底研究及成因再认识提供了地球物理学证据。