iTilt-Euler法在重力数据处理及断裂解释中的应用  

Application of iTilt-Euler deconvolution in gravity data processing and fault system interpretation

作　　者：陈青[1,2] 孙帅 丁成艺 黄小宇 陈浩 申鹏 罗港 魏耀聪 CHEN Qing;SUN Shuai;DING Cheng-Yi;HUANG Xiao-Yu;CHEN Hao;SHEN Peng;LUO Gang;WEI Yao-Cong(Department of Earth Science,School of Petroleum and Natural Gas Engineering,Chongqing University of Science and Technology,Chongqing 401331,China;Chongqing Key Laboratory of Complex Oil and Gas Exploration and Development,Chongqing 401331,China;Chongqing 208 Geoenvironmental Engineering Survey and Design Institute Co.,Ltd.,Chongqing 400700,China)

机构地区：[1]重庆科技学院石油与天然气工程学院,重庆401331 [2]复杂油气田勘探开发重庆市重点实验室,重庆401331 [3]重庆市二零八地质环境工程勘查设计院有限公司,重庆400700

出　　处：《物探与化探》2021年第6期1578-1587,共10页Geophysical and Geochemical Exploration

基　　金：国家自然科学基金项目(41702210);重庆市基础科学与前沿技术研究专项(cstc2017jcyjAX0370);重庆市教委科学技术研究项目(KJQN201901535);重庆科技学院博士教授科研启动基金项目(CK2016B12)。

摘　　要：为改善欧拉反演结果的收敛性,本文采用不依赖于构造指数的改进Tilt-Euler(iTilt-Euler)进行计算,并利用水平总梯度倾斜角峰值(TAHG)约束法约束反演数据,优化计算结果。模型试算结果表明,采用TAHG法约束的iTilt-Euler反演结果的收敛性得到了有效提高,且为深源地质体的位置和深度提供了更多信息。在肯尼亚ANZA盆地某区块重力数据处理中的应用表明,TAHG法约束下的iTilt-Euler反演解连续性较好,主要呈NW向,其次是NE向,且NW向展布的解延伸长、深度大,反映为控制区内构造单元边界的基底断裂,被NE向展布的盖层断裂所切割。此外,研究区东南部发育一条NNE向的深断裂,切割了NW向及NE向断裂,推测其可能控制了区域构造单元的东南边界。应用结果表明,iTilt-Euler法和TAHG法可为断裂解释提供可靠的研究手段,具有较好的实用性。In order to improve the convergence and stability of Euler inverted results,the iTilt-Euler method,which do not depend on the structure index,is used for the calculation.Furthermore,the data points are constrained by the peak values of tilt angle of the total horizontal derivative(TAHG) to optimize the solutions.The method has been demonstrated with synthetic and real data.For synthetic data,the convergence of iTilt-Euler inversion results constrained by the TAHG method is improved effectively to detect the fault structures with deeper depth.Application to gravity data for the ANZA basin in Kenya shows that the iTilt-Euler inversion results constrained by peak values of TAHG have good continuity.The results distribute generally along NW direction,followed by NE direction,and these characteristics are consistent with the identifying features of fault in the second-order vertical derivative and total horizontal derivative anomaly maps.Furthermore,the inversion depth results show that the solutions along NW direction are extend to large scale and with higher values,which is reflected as a basement fault that controls the boundary of the main tectonic units in the study area and usually cut by the superficial faults with NE extension.It is worth noting that a large deep fault with NNE extension is developed in the southeast of the study area,which cuts the north-west direction and the north-east direction fault.It is speculated that it may control the southeast boundary of the regional tectonic unit.We can conclude that the iTilt-Euler deconvolution combined with the peak constraint method can provide a reliable method for fault system interpretation,and has good practicability.

关 键 词：欧拉反褶积 重力异常 倾斜角 断裂系统 

分 类 号：P631[天文地球—地质矿产勘探]