氡气测量与CSAMT联合探测地下地质构造——以滇西潞西地区帕连、法帕剖面探测为例

The utilization of combined radon and CSAMT methods to detect underground geological structures:a case study of detection in Palian and Fapa profiles,Luxi area,western Yunnan Province

利用地球物理方法探测地下的地质构造,是工程地质、水文地质、地热调查等领域所考虑的重点之一。通常氡气测量的异常一般直接与地下的构造属性相对应,但无深度信息。CSAMT虽无法确定地质属性,但在确定地下构造的位置、宽度、产状方面具有较高的分辨率。在帕连和法帕进行探测的2个实例表明,组合探测分析可解决花岗岩体的侵入接触关系、背斜轴部灰岩与两翼碎屑岩的断层接触关系,查明发育于可溶岩与非可溶岩的接触面和温泉形成的地质条件,为工程地质病害评价、地热成因分析提供详细的地下地质构造信息。

Detecting underground geological structures is one of the key considerations for such work as engineering geology,hydrology and geothermic survey by using geophysical prospecting methods.Generally the anomalies of radon measurement directly determine the attributes of underground geological structures,but without penetrating depth information.CSAMT,though incapable of attributes identification,has high resolution in exploring the positions,widths and attitudes of geological structures.Two practical examples show that combined exploration analysis can solve such problems as intruding contact of the granite body,fault contact between limestone in the anticline center and clastic rocks in anticline limbs and can also explore geological conditions controlling thermal springs developed on the boundary between soluble and non-soluble rocks.All these data can be used to evaluate engineering geological disasters,analyze geothermal formation and provide detailed information of underground geological structures.