Improved tilt-depth method for fast estimation of top and bottom depths of magnetic bodies

作     者：王彦国 张瑾 葛坤朋 陈晓 聂逢君 

作者机构：东华理工大学放射性地质与勘探技术国防重点学科实验室南昌330013 

出 版 物：《Applied Geophysics》 (应用地球物理（英文版）)

年 卷 期：2016年第13卷第2期

页      面：249-256,416页

核心收录：

学科分类：081801[工学-矿产普查与勘探] 081802[工学-地球探测与信息技术] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：supported by National Natural Science Foundation of China(No.41504098 and 41504054) Natural Program on Key Basic Research Project(No.2015CB453002) 

主　　题：Tilt-depth method Buried depth Changling Fault Depression Volcanic rocks 

摘      要：The tilt-depth method can be used to make fast estimation of the top depth of magnetic bodies. However, it is unable to estimate bottom depths and its every inversion point only has a single solution. In order to resolve such weaknesses, this paper presents an improved tilt-depth method based on the magnetic anomaly expression of vertical contact with a finite depth extent, which can simultaneously estimate top and bottom depths of magnetic bodies. In addition, multiple characteristic points are selected on the tilt angle map for joint computation to improve reliability of inversion solutions. Two- and three- dimensional model tests show that this improved tilt-depth method is effective in inverting buried depths of top and bottom bodies, and has a higher inversion precision for top depths than the conventional method. The improved method is then used to process aeromagnetic data over the Changling Fault Depression in the Songliao Basin, and inversion results of top depths are found to be more accurate for actual top depths of volcanic rocks in two nearby drilled wells than those using the conventional tilt-depth method.