间接地形校正方法及其应用  

Indirect terrain correction method and its application,

作　　者：蔡鑫[1] 王宝仁[2] 

机构地区：[1]石油地球物理勘探局第五地调处 [2]中国地质大学(武汉)物探系

出　　处：《石油地球物理勘探》1990年第1期71-85,108+126,共17页Oil Geophysical Prospecting

摘　　要：为解决鄂尔多斯盆地黄土高原区具有双层结构复杂地形1:10万重力测量的地形影响问题而提出了“间接地形校正方法”。该方法是一个综合处理过程,它包括:1.将原始的重力异常计算成自由空间重力异常;2.用三角级数法把起伏地形面上的重力异常换算成某一高度平面上的重力异常,即“曲化平”;3.用频域正演公式G(u,v)=2πfe^(-kz)计算和消除层状起伏地形质量的重力效应;4.用回归分析方法消除地形校正的残差。该方法在进行传统地形校正的同时,还能方便地解决多层结构地形的校正问题,消除中间层密度取得不准和中间层密度横向变化引起的地形校正残差问题。理论模型的试算表明方法有较高的精度。通过工区近7000km^2内4974个点的实际资料处理,得到了清晰的异常形态,收到了良好的地质效果。Indirect terrain correction method was used to remove the terrain effect on 1:100000 gravity survey on complex two-layer structure ter- rain of loess plateau in Eerduosi sedimentary basin.It is a comprehen- sive method and includes the following steps: ·Convert raw gravity anomaly into free-air gravity anomaly. ·Use triangle series to convert the gravity anomaly on an undula- tony terrain into the gravity anomaly on a plane that is above the undulatory terrain.This procedure is called“reduced to datum”. ·Calculate and remove the gravity effect of layered undulatory ter- eain mass by using frequency-domain forward formula G(u,v)=2πfe^(-kz)·Use regression analysis to remove residual terrain effect. Besides traditional terrain correction,this method can make easy gravity correction in the case of multilayered terrain,and remove the residual terrain effect which is caused because mid layer density is inaccurate and variable laterally. Theoretical roodel test shows that this method is fairly accurate. The processing of gravity data of 4974 gravity stations on 7000 km^2 resulted in clear gravity anomaly map,thus creating a fine geological result.

关 键 词：地形校正 间接地形校正 地形质量正演计算 地形校正残差的消除 

分 类 号：TE13[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]