多种重磁位场边缘识别方法及在南黄海北部断裂构造识别中的应用研究

Multiple gravity and magnetic potential field edge detection methods and their application to the boundary of fault structures in northern South Yellow Sea

为了研究南黄海北部盆地及邻区的地质体接触关系和断裂构造在平面上的分布位置和走向,以解决研究区相关地质构造等问题。本次研究系统分析了多种重磁位场边界识别方法原理,应用各方法对研究区的重力资料进行处理,结合地震资料和相关地质认识,重新对研究区断裂构造进行识别和提取,确定研究区断裂体系和分析断裂特征,进行构造分区。研究结果表明,在传统处理方法基础上,联合归一化Theta图垂向导数、归一化标准差和归一化总水平导数垂向导数是划分断裂的一种有效方法,更能快速、有效、准确地反映出研究区断裂构造的平面特征。研究区发育NE(NNE)、NW、近EW和近SN向断裂构造,具有层次性、区域性和不同的活动性。NE(NNE)向断裂构成该区的主要构造格架,是研究区的构造主体,在长期剧烈活动作用下,NE(NNE)向断裂全区皆有分布,且主要分布于北部盆地及盆地以外的西北一带,而近EW向断裂主要分布于中部隆起一带。在特殊的构造应力环境下,北部盆地形成了前陆盆地的构造和地层展布特征,结合重力异常和地震资料认为,研究区可划分为鲁西隆起带、胶莱盆地、胶南隆起带、千里岩隆起带、南黄海北部盆地、南黄海盆地中部隆起带等6个构造单元。

In order to study the contact relationship of geological bodies and the distribution locations and trends of fault structures on the plane in the northern basin of the South Yellow Sea and its adjacent areas, the authors studied the related means used to solve the related geological structures in the study area. The principles of multiple gravity and magnetic potential field boundary detection methods were systematically analyzed, and the gravity data was processed by various methods in the study area. The fault structure was re-identified and re-extracted to study the system of faults and analyze the characteristics of faults, and the tectonic zoning was conducted in combination with seismic data and related geological recognition in the study area. The results indicate that the joint NVDR-Theta, normalized standard deviations and NVDR-THDR, based on the traditional processing methods, are effective methods for dividing faults. The planar characteristics and depth information of the faults can be more quickly, effectively and accurately reflected by the methods in the study area. NE(NNE)-, NW-, nearly EW-and nearly SN-trending fault structures are developed in the study area, which are hierarchical, regional, and different in activity. The NE(NNE)-trending faults form the main structural framework of the area are the main tectonic bodies of the study area. Under the action of long-term severe activity, NE(NNE)-trending faults are distributed throughout the fault area, and are mainly spread in the northern basin and the northwestern area outside the basin, while nearly EW-trending faults are mainly distributed in the central uplift area. The structure and stratigraphic distribution of the foreland basin were formed in the northern basin under the special tectonic stress environment. Six tectonic zones were recognized in combination with the gravity anomalies and seismic data in the study area, which include Luxi uplift, Jiaolai basin, Jiaonan uplift, Qianliyan uplift, the northern basin of the South Yellow Sea, and the central uplift of the South Yellow Sea.