吉林省区域重、磁场综合信息解析及地质意义探讨

Research on regional gravity and magnetic field based on synthetic information and discuss its geological significance in Jilin Province

吉林省区域重力场特征可分为三级:一级异常为全区的背景场;二级异常为研究区内部大型重力高和重力低以及延伸较大的重力梯级带;三级异常表现为地块内部隆起与断陷引起的异常。区域磁场特征总体可分为三种:正异常区、负异常区、异常陡变带。对重力、区域磁场数据进行了上延5 km、10 km、20 km、50 km高度延拓,分别计算四个方向(0°、45°、90°、135°)的水平一阶导数、垂向二阶导数,在此基础上解析了区域线性构造、环形构造、基底构造特征。对区域断裂特征及分布进行了研究,提出7、8号断裂带是华北板块构造单元界线。区域矿产资源分布受线性构造、环形构造、基底构造控制。

The characteristics of regional gravity field in Jilin Province can be divided into three levels:the first-order anomaly is the background field of the whole region;the second-order anomaly are the large-scale gravity highs and gravity lows and gravity gradient belts within the study area;the third-order anomaly are some internal uplifts and faults in block.Regional magnetic field characteristics can be divided into three types:positive anomalies,negative anomalies and mutation belts.The regional gravity and magnetic field data was analytical continuation at 5 km,10 km,20 km,and 50 km height,horizontal first stage derivative and vertical second stage derivative on the four directions(0°,45°,90°,and 135°)were calculated.The regional linear structure,the ring structure,and the base structure characteristics are resolved on this basis.On the study of characteristics and distribution of the regional faults,we think the No.7 and No.8 fault zones are the structural unit boundary of the North China plate.The distribution of regional mineral resources is controlled by linear structures,ring structures,and base structures.