高密度电阻率法的异常识别和推断——以溶洞探测和寻找地下水为例  

Anomaly identification and inference of high density resistivity method:take karst cave exploration and groundwater exploration as an example

作　　者：马吉静 MA Ji-jing(Institute 290 of Nuclear Industry,Guangdong Shaoguan 512029,China)

机构地区：[1]核工业二九○研究所

出　　处：《地球物理学进展》2019年第4期1489-1498,共10页Progress in Geophysics

摘　　要：文章结合大量的探测实践,构设了探测深度h与供电极距AB的经验关系式,关系式不仅说明深度与供电极距的关系,同时也说明了地质性质对深度的影响,并因此引入测深调整因子.在此基础上,由深度的经验计算式导出了视电阻率计算式,视电阻率计算式表明,均质完整大地或岩层断面电阻率场的分布规律是:从上(浅)到下(深)等值线规则分布、阻值规则增大;而不均质和不完整的地质岩层断面电阻率场的分布特点是:断面电阻率等值线杂乱不规则,有阻值不同的异常区域或圈闭异常,异常区域或圈闭异常大小、位置、形态无确定性.这两者是高密度电阻率法识别和推断目标地质体的基础.与不均质大地相比,目标地质体异常有其属性包括产生形成条件的一定的确定性,如溶洞有电性、大小、位置、形态上的确定性,富含水地层有电性和条件上的相应确定性.因此,依据均质大地、不均质大地和目标地质体各自的电阻率特点,以及实际的地质情况和成因条件,可对目标地质体的异常进行识别和推断.Combined with a large number of exploration practices,the empirical formula between exploration depth h and power supply polar distance AB is established in this Article,which indicates not only the relationship between the depth and the power supply polar distance,but also the influence of geological properties(αandβrepresent geological properties)on the depth.In addition,and the formula introduces adjustment factor(0.1~0.3).The apparent resistivity calculation formula is derived from the empirical formula of depth,which demonstrates the distribution law of resistivity field of homogeneous earth cross section:regular contour distribution from top(shallow)to bottom(deep),and regular increase of resistance value.The distribution characteristics of resistivity field of inhomogeneous earth cross section are as follows:The resistivity contour of earth cross section is disorderly and irregular;there are abnormal regions or closed circles with different resistances;and the size,position and shape of abnormal regions or closed circles are uncertain.These two methods are the basis of anomaly recognition and inference in detecting target geological bodies using high-density resistivity method.Compared with inhomogeneous earth,The resistivity anomalies of many geological bodies have their certainties in their properties,such as the certainty in electricity,size,location and morphology of karst caves,and the certainty of the electricity and conditions or morphology of water-rich strata.Therefore,anomalies of the target geological body can be recognized and inferred according to the resistivity characteristics of homogeneous earth,inhomogeneous earth and target geology,as well as the actual geological conditions.

关 键 词：完整均质大地 不均质大地 规整等值线 不规整等值线 异常区域 圈闭异常 

分 类 号：P631[天文地球—地质矿产勘探]