【摘要】 松辽盆地北部发育的中-新生代反转构造代表着盆地继伸展裂陷阶段、热冷却拗陷阶段之后的第3个构造演化阶段。系统收集了布设在覆盖大安-德都断裂及其附近的14个3维地震工区,30条区域地震反射大剖面,在此基础上准确追踪解释了T06、T1、T11、T2、T3、T4、T5等7个地震反射层位。同时基于52口钻孔的资料对重点反射层的地质年代进行了重新厘定,分析了不同时期断层展布特征及分布规律,重点就松辽盆地中新生代反转构造的几何学形态、变形特征与机制进行了研究。研究结果认为,该反转构造为大安-德都断裂在中生代末期和新生代早期的主要变形模式,符合"逆断层-褶皱"构造的几何形态和变形机制。松辽盆地内部的构造变形主要集中在该构造反转带上。此外,重点选择了2条典型剖面开展了野外实验性浅层人工地震勘探。根据勘探结果并结合该地区第四纪地层厚度分析认为,广泛发育在背斜顶部且断错T06界面的小断裂可能代表了大安-德都断裂强变形带的最新活动性,勘探剖面揭示的上断点断错最年轻地层为中更新统,并据此初步判定该断裂最新活动时代可能为中更新世。此外,综合人工地震勘探结果、现代地震活动性和震源机制解研究结果认为,大安-德都断裂的"逆断层-褶皱"构造反转带最新的活动已明显影响到了近地表的反射层,清楚断错了早-中更新世地层,控制着断裂附近中强地震的发生,是松辽盆地内部或整个东北地区重要和典型的发震构造之一。更多还原

【Abstract】 Meso-Cenozoic inversion structures developed in northern Songliao Basin represent the third tectonic evolution stage of the basin following the rifting stage and the depression stage of thermal cooling. The paper collects systematically 30 regional seismic reflection profiles laid out to cover the Da’an-Dedu Fault and its adjacent14 3-D seismic projects,and on this basis,accurately tracks and interprets a total of seven seismic reflection horizons of T06,T1,T11,T2,T3,T4 and T5. At the same time,geological age of key reflection horizons is re-determined based on 52 boreholes data,the distribution characteristics and pattern of different periods are analyzed,and the geometric configuration and deformation characteristics and mechanisms of Meso-Cenozoic inversion structures developed in the northern Songliao Basin are discussed in particular. The study concludes that the inversion structure is the main deformation model of Da’ anDedu Fault in the late Mesozoic and early Cenozoic,which coincides to the geometric shape and deformation mechanism of the "thrust-fold"structures.Based on the experimental shallow seismic exploration results of section line No. 10 and No. 11 in the research area,we find that the small faults,which are widely developed on the top of anticline and disconnect the reflection interface of T06,represent the latest activity of Da’an-Dedu Fault,and the deformed layer formed in mid-Pleistocene may indicate the latest activity time of Da’ an-Dedu Fault,which is mid-Pleistocene.In addition,according to the study on shallow seismic exploration results,modern earthquake activity and focal mechanism solutions,we strongly believe that the latest activity of "thrust-fold "inversion structures of the Da’an-Dedu Fault has an obvious effect on the near surface reflection layers,which offsets the lower-middle Pliocene and controls the moderate-strong earthquake activity of the research area and the adjacent areas. These structures should be regarded as one of the most important and typical seismogenic structures in the interior of Songliao Basin and in the Northeast China region. Based on this,we can understand scientifically the deformation process of the interior of Songliao tectonic block through the research of structural deformation of Da’an-Dedu Fault developed inside the block after the late Cenozoic era,and the future earthquake activities controlled by the Da’an-Dedu Fault.更多还原