重力梯度数据协克里金三维反演确定岩脉倾向  

Identify the Dip Angle of the Dipping Dike Model Based on Cokriging Inversion of Gravity Gradient Data

作　　者：高秀鹤 黄大年[1] 孙思源[1] 于平[1] 

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026

出　　处：《吉林大学学报（地球科学版）》2017年第2期589-596,共8页Journal of Jilin University：Earth Science Edition

基　　金：国家高技术研究发展计划("863"计划)项目(2014AA06A613);吉林大学研究生创新基金资助项目(2016095)~~

摘　　要：采用协克里金法处理重力或重力梯度数据反演地下3D密度时,岩脉倾角的先验信息是否合理决定了反演结果的好坏。为了使协克里金法在先验信息不充足时也能得到理想的反演效果,我们提出角度扫描的方法来获取岩脉倾角信息:在保持其他反演参数不变的前提下,假设模型的倾斜角度未知,每次引入不同角度进行协克里金反演,再根据先验信息剔除不合理密度值,得到密度分布;统计预测数据与测量数据拟合残差的标准差,根据极小值对应的角度估计岩脉的倾角。本文基于4种不同倾斜角度(0°,45°,90°,135°)岩脉模型的重力梯度垂直分量Tzz验证方法有效性,都能够准确地估计出岩脉倾斜角度。这使得协克里金法在岩脉倾角未知的情况下,也能得到较好的反演结果。When we invert gravity gradient data to recover 3Ddensity distributions by cokriging,the dip angle impacts the recovered results seriously.Where there is a lack of the prior information about dip angle,to obtain reasonable results we present a method to determine the angle.Keeping the parameters same in cokriging,we introduce some different angles,then according to the prior information,only zero or positive density contrast is chosen.The standard deviation of the residuals between the observed and predicted data changes with the angle changing.The evaluated angle of this method is the corresponding angle to the minimum standard.In this paper,we choose four typical dipping dike modelswith the dip angle of 0°,45°,90°,135°respectively.The vertical component Tzzof the gravity gradient data is inverted to test the valid of the method,and it shows the correct dip angles of the dipping dike.This result makes cokriging can be applied in more conditions that the dip angle is unavailable.

关 键 词：协克里金 三维反演 重力梯度 岩脉模型 

分 类 号：P631.1[天文地球—地质矿产勘探]