CSAMT与激电综合寻找铅锌矿研究

发布时间：2018-05-15 19:08

本文选题：CSAMT + 激发极化法　；参考：《成都理工大学》2015年硕士论文

【摘要】：激电是常用的电法勘探方法,但针对一些构造和岩性复杂地区的深部目标体存在的测量噪声严重、电磁信号弱的特点,单一的电法勘探手段在解释推断时存在误差且可信度低、抗干扰能力弱等问题,这严重影响了其在深部矿产资源的探测效果,因而在复杂构造和岩性地区寻找隐伏型铅锌矿急需合适、有效的技术方法指导找矿,而CSAMT法正好弥补了单一使用激电方法的不足,因此本文对CSAMT与激电综合寻找铅锌矿的应用作了研究。本文首先阐述了CSAMT和激发极化法的发展状况,再就CSAMT测量中产生畸形数据的原因作了分析,并讨论了场源效应、静态效应、近场效应的校正方法。同时,介绍了Bostick方法与非线性共轭梯度法求解反问题,通过软件建立不同理论模型,对比分析TE、TM模式的成像规律,确立以TM模式作为实测资料的反演模式,验证了所用软件对解释推断的可靠性。然后利用有限单元法建立激发极化理论正演模型,对正演计算结果进行阻尼最小二乘反演,分析反演结果的异常特征及走向,总结电阻率和极化率成像规律,为实测资料反演提供依据。论文最后以贵州某铅锌矿区为例,结合矿区地质资料和岩(矿)石物性,确定矿区三条CSAMT法反演剖面的断裂构造倾向和蚀变带的位置;根据激电普查结果,选取一条拟断面进行激电测深,确定低阻高极化体的异常特征及走向,综合推断出可能存在的铅锌矿带或成矿远景区。通过CSAMT和激发极化法在复杂构造和岩性矿区的应用得到如下结论:1、CSAMT法中存在的数据畸变主要是由静态效应引起的,通过曲线平移和空间滤波进行校正。2、CSAMT层析成像结果能较好地区分存在电性差异的岩体、蚀变带、断层等异常体,为分析成矿机制和控矿因素提供依据。3、激发极化法反演结果中电阻率与CSAMT视电阻率剖面的对比可增加异常解释推断的依据,极化率为岩(矿石)的异常特征走向提供丰富的信息。4、CSAMT与激发极化法综合探测,提高了探测结果解释推断的可信度,体现了综合模式在复杂构造和岩性地区探测深部铅锌矿的有效性和可行性。
[Abstract]:Induced electricity is a commonly used method of electrical exploration. However, in view of the serious measurement noise and weak electromagnetic signal in some deep target bodies in complex structural and lithologic areas, the single method of electrical exploration has errors and low reliability in interpreting and inferring. The ability of anti-interference is weak, which seriously affects the exploration effect of deep mineral resources. Therefore, it is urgent to find hidden lead-zinc ore in complex tectonic and lithologic areas, which is in urgent need of appropriate and effective technical methods to guide prospecting. The CSAMT method can make up for the shortage of the single IP method, so this paper studies the application of CSAMT and IP to find lead-zinc ore. In this paper, the development of CSAMT and induced polarization method is described, then the causes of abnormal data in CSAMT measurement are analyzed, and the correction methods of field source effect, static effect and near field effect are discussed. At the same time, the Bostick method and the nonlinear conjugate gradient method are introduced to solve the inverse problem. Different theoretical models are established by software, and the imaging laws of the TM model are compared and analyzed, and the inversion model using TM model as the measured data is established. The reliability of the software is verified. Then the forward model of induced polarization theory is established by finite element method, and the damping least square inversion of forward calculation results is carried out. The anomalous characteristics and trend of inversion results are analyzed, and the law of resistivity and polarizability imaging is summarized. It provides the basis for inversion of measured data. Finally, taking a lead-zinc mine area in Guizhou as an example, combined with geological data and petrophysical properties of the mining area, the fault structural tendency and the location of alteration zone of three CSAMT inversion sections in mining area are determined, and according to the results of induced electric survey, A pseudo section is selected for IP sounding to determine the anomalous characteristics and direction of low resistivity and high polarimetric bodies and to infer synthetically the possible lead and zinc ore belts or metallogenic scenic spots. Through the application of CSAMT and induced polarization method in complex tectonic and lithologic mining areas, it is concluded that the data distortion in the 1: 1 CSAMT method is mainly caused by static effects. By means of curve translation and spatial filtering, the results of CSAMT tomography can be used to distinguish the abnormal bodies, such as rock mass, altered zone, fault and so on, which have different electrical properties. For the analysis of ore-forming mechanism and ore-controlling factors, the correlation between resistivity and CSAMT apparent resistivity profile in the inversion result of induced polarization method can increase the basis of abnormal interpretation and inference. The polarizability provides abundant information for the abnormal characteristic trend of rock (ore) .4CSAMT and the induced polarization method, which improves the reliability of the interpretation and inference of the exploration results. The effectiveness and feasibility of the integrated model in the exploration of deep lead-zinc deposits in complex tectonic and lithologic areas are demonstrated.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.3;P618.4

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