太行山片麻岩基岩裂隙富水性的金属因素特征——以易县为例

Metallic factor characteristics of water yield property in gneiss rock fissure of Taihang mountains

为研究金属矿化效应对太行山片麻岩基岩裂隙地下水勘查时的影响,依据区域地质资料,分析了易县某研究区的水文地质特征,总结了该研究区片麻岩基岩裂隙水的赋存规律。利用激发极化法获取了金属因素和极化率,分析了研究区金属因素的特征,讨论了金属因素与基岩裂隙水富水性的关系,并布置地质钻孔验证了基岩裂隙水富水性与金属因素特征之间的对应关系。结果表明:在无金属矿化效应影响的地区,金属因素曲线和极化率曲线大体上呈现水平轴对称形态;在有金属矿化效应影响的地区,金属因素曲线和极化率曲线形态基本相同;金属因素全曲线和极化率全曲线均同时快速增加,意味着研究区存在金属矿化效应影响的可能性急剧加大;金属因素大于1×102/(Ω·m),极化率大于3%,研究区存在较为明显的金属矿化效应影响;相比极化率,金属因素对地下水勘查时金属矿化效应影响的分辨能力有较大程度的提高,效果可靠,在条件类似的存在金属矿化效应影响的太行山片麻岩基岩裂隙水分布区具有推广性。

To study the metal mineralization effect on underground water survey in gneiss rock fissure of Taihang mountains,hydrogeological characteristics of a research area in Yi County were analyzed with regional geologic data,and assignment law of gneiss bedrock fissure water was summarized.Metallic factor and polarizability were acquired by induced polarization method.Metallic factor characteristics of the research area were analyzed,and the relationship between metallic factor and water yield property in rock fissure water was discussed.Geology drill was distributed to test and verify the correspondence.The results showed that curves of metallic factor and polarizability presents horizontal axisymmetric morphology in area without metal mineralization effect,and curves of metallic factor and polarizability basically present the same form in area with metal mineralization effect.When the whole curves of metallic factor and polarizability uplifted sharply,the probability of metal mineralization effect increased quickly.There was obvious metal mineralization effect with metallic factor above 1×10^2/(Ω·m)and polarizability above 3%.In comparison with polarizability,the resolution of metallic factor enhanced with reliable effect,and it had the best performance in gneiss rock fissure water area with similar metal mineralization effect in Taihang mountains.