松辽盆地外围通化地区高精度重磁电特征及其构造格架

通化地区是松辽盆地东部外围的油气调查新区,油气勘探程度极低,关键问题是沉积地层展布形态、盆地深部结构等关键基础地质问题未知。笔者通过高精度重力、磁力和大地电磁等地球物理方法,获取了通化地区岩石地球物理和重磁异常变化特征,揭示了通化地区深部地球物理结构形态;认为通化地区存在4条Ⅰ级断裂和46条次级断裂,主要断裂控制着研究区的基本构造格架;首次圈定出红庙子、桓仁、沙尖子、拐磨子和木齐盆地5个断陷盆地,查明了盆地规模、中生界底面最大埋深和中侏罗统侯家屯组地层的展布形态等深部结构特征;并进一步对桓仁盆地和拐磨子盆地进行构造单元的划分。该研究成果为下一步油气勘探提供重要基础地质信息,亦对松辽盆地东部外围新区的油气勘探部署提供重要的指导意义。

Lithofacies identification and deep structure of Tonghua area in the periphery of Songliao Basin based on high-precision gravity-magnetic electrical survey

Tonghua area is a new oil and gas exploration area in the periphery of eastern Songliao Basin and is characterized by low-grade degree oil and gas exploration. The key geological problems such as sedimentary stratigraphic distribution features and deep structure characteristics of the basin remain unknown. Gravity-magnetic-electrical exploration is an important method for revealing the deep structural features and structural framework of the basin. Based on several gravity-magnetic-electrical survey lines, the authors obtained the comprehensive interpretation of Tonghua area tectonic framework. There are 4 class-I faults and 46 secondary faults in the Tonghua area, which control the basic tectonic framework in the study area. For the first time, five faulted basins were identified, namely Hongmiaozi, Huanren, Shajianzi, Guanmozi and Muqi basin. The scale of the basin, the maximum buried depth of the Mesozoic strata, the features of Houjiatun Formation and deep structural framework were determined in this study. In addition, the authors carried out the division of tectonic units in the Huanren Basin and the Guaimozi Basin. This study would provide important basic geological information for further oil and gas exploration, and also have great guiding significance for exploration and deployment in the new periphery areas of eastern Songliao Basin.