地球物理技术在海砂矿资源评价及选址中的应用

The application of geophysical technology in the evaluation and site selection of sea sand mineral resources

为进一步提高海砂资源勘查的效率与精度,以某海域经济开发区海砂矿资源评价及选址项目为例,采用多波束测深、单道地震系统、侧扫声呐及钻探等技术,较为精细地刻画海底地形、微地貌及浅部地层特征,探明了砂体的沉积格局及平面展布规律,厘清了工程区海砂资源的分布范围和厚度特征。以单道地震剖面及钻孔约束数据为基础,结合高分辨率地形水深数据,建立海砂体的DEM模型对工程区海砂资源量进行评价,并采用地质块段法对矿体进行验证性估算。模型计算结果表明:海砂的总资源量约为2.017×10~7 m^(3),地质块段法计算海砂矿总资源量约为1.905×10~7 m^(3),两者相差5.55%,,两者相互验证,满足估算精度要求,有效保障海砂体积的计算精度;地球物理方法的应用能有效提高海砂资源量探测精度,降低探测成本,可广泛应用于海域海砂资源量探测,应用前景广阔。

In order to further improve the efficiency and accuracy of sea sand resource exploration,taking the evaluation and site selection project of sea sand mineral resources in a certain sea economic development zone as an example,techniques such as multi beam bathymetry,single channel seismic system,side scan sonar,and drilling were used to accurately depict the seabed topography,micro topography,and shallow stratigraphic characteristics.The sedimentary pattern and plane distribution pattern of sand bodies were explored,and the distribution range and thickness characteristics of sea sand resources in the engineering area were clarified.Based on single channel seismic profiles and borehole constraint data,combined with high-resolution topographic water depth data,a DEM model of sea sand bodies is established to evaluate the amount of sea sand resources in the engineering area,and the geological block method is used to validate the estimation of the ore body.The model calculation results indicate that the total resource of sea sand is approximately 2.017×10~7 m~3,calculated by the geological block method,the total resource of the sea sand mine is approximately 1.905×10~7 m~3,the difference between the two is 5.55%,and the two are mutually verified to meet the estimation accuracy requirements,effectively ensuring the calculation accuracy of sea sand volume;The application of geophysical methods can effectively improve the accuracy of detecting sea sand resources,reduce detection costs,and can be widely applied in detecting sea sand resources in the sea,with broad application prospects.