物探数据在三维地质建模中的应用--以新疆哈密盆地为例

摘要

3D Geological structural model plays a major role in showing the geological information,and has been an essential part of hydrogeology engineering proj ects.For the lack of borehole data in most regions and the advantages of geophysical technology,this paper takes Hami Basin of Xinjiang where the geophysical data is rich for example, according to the theoretical basis of crusting weathering crust and the change trend of apparent resistivity from geophysical data,the determination method of discrete data inflexion point is applied to classify geological structure,and the classification is verified using drilling hole data;then,to divide the regional geological structure more detailedly,virtual geophysical measurement points are set in deleted regions of geophysical data,and virtual geophysical measurement points are assigned using the distribution of surface quaternary thickness,and according to the layered location of nearby geophysical measurement points;finally,the more accurate 3D geological section model of study area is established using GOCAD.3D geological section model provides the theoretical basis for further groundwater flow study and water balance calculation,and through showing the modeling process,this paper provides a new idea of regional 3D geological modeling using geophysical data.%在地质信息应用方面，三维地质结构模型有着重大表现能力，成为水文地质工程项目中不可缺的部分。目前，多数地区钻孔资料不足，针对物探技术的优势，笔者以物探资料丰富的新疆哈密盆地为例，根据风化壳划分理论基础和物探数据中视电阻率的变化趋势，利用离散数据拐点确定方法进行物探测量点的地质结构划分，并利用钻孔资料对分层结果进行验证；然后在物探数据缺失区设置虚拟物探测量点，根据地表第四系厚度分布情况，按照就近物探测量点的分层位置对虚拟物探测量点进行分层，使得全区地质结构的划分更加细致；最后在 GOCAD软件中建立了研究区较为准确的三维地质模型。三维地质结构模型为进一步的地下水流动研究及水均衡计算提供了理论依据。通过对建模过程的展示，提供了利用物探数据进行区域三维地质建模的一种新思路。