云南某铜多金属矿激电找矿研究

发布时间：2018-03-08 10:10

本文选题：有限单元法　切入点：最小二乘法　出处：《成都理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：激发极化法是当前在寻找金属矿产中一种被广泛应用的一种方法,它以分辨率高和工作效率高的特点受到了一致的肯定。在双频激电实际工作中,常用视频散率P和视电阻率ρ来对异常进行评价,对异常有时难以做出准确的解释。因而为突出与金属矿密切相关的激电异常,压制干扰因素异常,对这两种参数进行乘除变换,得到一个新的参数,定义为视激电率J,旨在通过视激电率J来提取异常的二次信息,并在实例上进行应用研究。本文首先介绍了有限单元法正演理论和最小二乘法反演理论,并且为了研究视激电率J的可行性,应用有限单元法理论来建立正演模型,观察到明显的效果后,将视激电率J应用于云南某铜多金属矿幅频激电勘探。在对该矿区进行幅频激电扫面,得到研究区域的实测P和ρ的数据值的基础上,对这两种参数的异常特征进行分析;再将P除以ρ得到的本文需要的视激电率J参数,得到视激电率的异常特征,并与视频散率和视电阻率的异常特征进行对比,找出三种参数异常特征的异同,对比它们反映场源体特征的效果。通过对研究区物性参数和地质概况的分析,表明该地区反映铜多金属矿(化)的有效异常为低阻高极化。根据扫面获得的电阻率和极化率结果圈定了三个异常带,并推断其中一个为高阻高极化,另两个为低阻高极化带。为了判断上述异常带极化体的范围、深度及产状等特征,在异常明显而且连续的地方布置精测剖面,进行大功率中间梯度方法、磁法及偶极-偶极幅频激电测深,并对测深数据进行最小二乘法反演,绘制拟断面。在对三种异常对比分析的基础上,结合研究区地质和物性参数特征分析研究,获得如下结论:本区两个低阻高极化带矿化现象比较普遍,其中Y3异常带三种参数异常对应好,与已知矿点异常特征相似,推断其视频散率异常均由蚀变长石石英砂岩底板与粉砂质板岩接触的层间破碎带中的铜矿引起,推测成矿可能性较大,Y2异常区激电异常复杂多变,需进一步详查;高阻高极化异常带推测是由高阻体(浅部石英脉)或属于离子导体的固体电解质与周围溶液形成的双电层引起;视激电率异常对突出有意义异常、压制干扰异常有较好的效果。
[Abstract]:The method of induced polarization is a widely used method in searching for metal minerals at present. It has been confirmed by the characteristics of high resolution and high working efficiency. Video dispersion P and apparent resistivity 蟻 are commonly used to evaluate anomalies, and it is sometimes difficult to make an accurate explanation of anomalies. Therefore, in order to highlight the induced anomalies closely related to metal mines, the abnormal interference factors are suppressed. By multiplying and dividing the two parameters, a new parameter is obtained, which is defined as the apparent ionization rate (J), which is used to extract the secondary information of the anomaly through the apparent ionization rate (J). In this paper, the forward modeling theory of finite element method and the least square inversion theory are introduced, and in order to study the feasibility of apparent ionization rate J, the forward modeling is established by using the finite element method theory. The apparent ionization rate J was applied to the amplitude-frequency induced electric prospecting of a copper polymetallic ore deposit in Yunnan Province after the obvious effect was observed. On the basis of the amplitude-frequency excitation sweep surface of the mining area, the measured values of P and 蟻 in the study area were obtained. The anomalous characteristics of the two parameters are analyzed, and then the abnormal characteristics of the apparent ionization rate are obtained by dividing P by 蟻, and the anomalous characteristics of the apparent ionization rate are compared with those of the video divergence rate and the apparent resistivity. This paper finds out the similarities and differences of the abnormal characteristics of three parameters, compares their effects on reflecting the characteristics of the field source body, and analyzes the physical parameters and geological profiles of the study area. It is shown that the effective anomaly reflecting copper polymetallic ore in this area is low resistivity and high polarization. According to the results of resistivity and polarizability obtained from sweep surface, three anomalous zones are delineated, and one of them is deduced to be high resistivity and high polarization. The other two are low resistivity and high polarization zone. In order to judge the range, depth and occurrence of the polarization body in the above anomalous zone, fine profile is arranged in the place where the anomaly is obvious and continuous, and the high-power intermediate gradient method is carried out. Magnetic method and dipole-dipole amplitude-frequency induced sounding are used to invert the bathymetric data and draw the pseudo section. On the basis of the comparison and analysis of the three anomalies, the characteristics of geological and physical parameters in the study area are analyzed and studied. The results are as follows: the mineralization of two low-resistivity and high-polarization zones in this area is quite common, and the three parameter anomalies of Y3 anomaly zone correspond well, which are similar to the characteristics of known ore spot anomalies. It is inferred that the anomaly of video dispersion rate is caused by copper in the interlaminar fracture zone where the base plate of altered feldspar quartz sandstone and silty slate contact with each other. It is inferred that the possibility of mineralization is more complicated and changeable in the anomalous area of Y2 anomaly, which needs further detailed investigation. The high resistivity and high polarization anomaly zone is supposed to be caused by the double electric layer formed by the high resistivity body (shallow quartz vein) or the solid electrolyte which belongs to ionic conductor and the surrounding solution, and the abnormal apparent ionization rate has a good effect on outburst of significant anomaly and suppression of interference anomaly.
【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;P618.2

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