内蒙古中东部残山丘陵草原覆盖区化探方法研究  

GEOCHEMICAL METHODS FOR GRASSLAND-COVERED HILLY TERRAINS IN CENTRAL-EASTERN INNER MONGOLIA

作　　者：刘汉粮[1] 迟清华[1] 王玮[1] 王学求[1] 周建[1] 

机构地区：[1]中国地质科学院地球物理地球化学勘查研究所,河北廊坊065000

出　　处：《物探与化探》2013年第3期382-388,共7页Geophysical and Geochemical Exploration

基　　金：中国地质调查局地质调查项目(1212010916034)

摘　　要：在内蒙古中东部针对半干旱残山丘陵草原覆盖区开展1∶20万区域化探方法研究。在典型已知矿区进行了流长、层位和粒级方法试验,以及不同采样密度、采样粒级的面积试验。结果表明:采样深度为20～80 cm时可以有效地发现异常,但为了提高采样效率,避免风成沙干扰,建议采样深度在钙积层上方40～80 cm为宜;流长从500～3 500 m都可以有效发现区域异常,因此流长对1∶20万或1∶25万区域化探调查影响不大;-120目细粒级沉积物样品中,贫SiO2而富集各种成矿元素及伴生元素,受风成沙稀释影响较小,是1∶20万区域化探调查的最佳采样介质。根据试验结果,对该景观区进行2 000 km2的1∶20万区域化探调查示范,结果表明,在已知矿区均能获取清晰的成矿元素地球化学异常,且在其他地方也发现了多处异常,证明了所选采样介质的有效性;与1∶20万区域化探调查数据进行对比,发现本此研究圈定的成矿元素异常强度高、范围大,显著避免了风成沙对元素含量稀释的影响。因此,-120目细粒级沉积物样品可作为该景观区1∶20万区域化探调查的最佳采样介质。The authors carried out the study of geochemical methods for grassland-covered hilly terrains in Dong Ujimqin Banner, Inner Mongolia. The methodological testing of length-grade-horizon and the areal testing of different densities-grades were applied in typical deposits. The conclusions are as follows- The samples at the depth of 20 - 80 cm can effectively reflect anomalies, and soils at the depth of 40 - 80 cm are the best sampling media to improve the efficiency. The samples collected 500 - 3 500 m away from the source area can reflect anomalies. The grade of - 120 mesh which is poor in SiO2 and enriched with metallogenic elements is the effective sampling media for regional and follow-up geochemical survey. A 2 000 km2 （ at the scale of 1 ： 2 000 000） regional geochemical dem- onstration reconnaissance was conducted in this landscape, and a comparison with the previous work was carried out. The results indi- cate that the intensity and boundary of ore-forming element anomalies are clearer and the influence of aeolian sand is minimized in this case. The grade of -120 mesh is the best media for 1：2 000 000 regional geochemical

关 键 词：残山丘陵草原覆盖区 内蒙古中东部 化探方法试验 1∶20万化探调查示范 

分 类 号：P632[天文地球—地质矿产勘探]