北方干旱区水地球化学方法应用效果

Applied Effect of the Hydrogeochemical Method in the Dry District of North China

北方干旱区由于雨水稀少，地下水多以井水（或泉水）的形式分布。取样宜于同一季节，以旱季最佳，该季节的地下水中元素含量相对较高。水中微量元素含量很低，多为10－9级，野外取水样时多采用元素预富集技术，如共沉淀技术和聚氨脂泡塑吸附技术等，分析测试主要采用光谱定量分析。水地球化学异常解释时必须紧密结合地质特征和水文地质条件，对异常作出正确解释和恰当评价。通过几个已知点试验研究，并扩大调查面积，对铜铅锌等有色金属矿、金银等贵金属矿、放射性铀矿以及地热等矿产资源，均取得了明显的应用效果，指出了试验区外围具有普查找矿价值的异常多处，特别在厚层疏松复盖层地区开展水地球化学调查应用效果尤为独特。水地球化学方法一般适用于区域普查阶段。

Because of few rainfall, the groundwater in the dry district of North China distributs mainly in form of. well or spring water. Samples collection need to be completed in the same season, panic.ularly, the dry season is very good. The reason is element contents higher than other season in the groundwatet of the dry season. The trace element contents of the water is quite low, it is generally 10-9 level. When samples were collected from the water in field, some element preconcentration techniques should be usually used, such as the together sediment and the polyurethane foamed plastics absorption technologies and so on. The spectral quantitative analysis are mainly used as measurement means. When hydrogeochemical anomalies are interpreted, geological characteristics and hydrological data must be closely combined, in this way, the anomalies can be rationally explained and properly evaluated. By means of experimental studies on the several known points, and by way of expansion in the investigation areas, the obvious applied effect of the hydrogeochemical method was already obtained in exploration of dineral resouces of copper, lead, zinc,gold, silver, uranium and geothermal energy etc., and may be especially made distinctive effect in the loose thick overburden area to develop hydrogeochethemical survey. Some anomalies be provided with value of general survey and prospecting ore are pesented in the periphery of the experimental study area. The hydrogeochemical method is usually applicable to general survey of region.