复杂地形条件下高精度重力勘探的地质效果

Geological effect of high-accuracy gravity prospecting in complicated landforms

分别用斜顶三棱柱体及方柱体模型分近、中、远区对某山区1：5万高精度重力勘探成果进行地形改正。用常规方法对地改后的布格重力异常进行处理效果不佳。本文提出了一种二维视深度滤波法，其实现过程为：首先利用解析法对观测数据向上延拓，然后利用差分法向下延拓，重复进行上、下延拓一定的次数，再用差分法向下延拓一次，达到滤波的目的。用此法对某山区资料进行处理，并与地震及钻井资料对比分析，取得了令人满意的效果。

Terrain effect of 1: 50000 gravity prospecting result in mountainous region is removed by respectively using slope-top trihedral prism model and rectangular prism model in near, mid and far areas. Conventional methods fail to bring good processing result of gravity anomaly which has undergone terrain correction. 2-D apparent depth filtering method is taken, which includes following steps: upward continuation of observed data by analytic way, downward continuation using difference means, repeated upward and downward continuations in several times, and last downward continuation using difference means to achieve this filtering. The method has been used to process gravity data in a mountainous region. The processed result has been cornpared with corresponding seismic data and borehole data to show satisfactory effect.