随着浅地表矿床发现的难度增大,资源勘查深度增加,三维建模技术在深部找矿中作用更加突出。三维地质模型的精确程度直接决定了对地质背景及成矿条件的认知程度,为此提出了一套基于航磁资料处理与三维可视化相结合的三维地质建模技术。对研究区选取适当剖面进行二维反演,获得各剖面地质模型。通过剖面相连法构建各地质单元的三维地质模型后,引入起伏地形三维块体磁场正演技术,对构建的三维初始模型正演计算,从而获取全区三维地质模型及各地质单元的航磁异常理论响应。与实测结果对比分析后,合理添加地质约束条件,重新修正模型,使得构建的模型最大程度接近实际情况,这样模型既能很好地反映地质信息,又能满足观测场与理论场的拟合误差最小,最大限度发挥地质学家的经验和对区域地质的理解。利用主块体和次级块体思想对地质体进行剖分建模,在保证模型精度的同时,减少总的模型块体个数,大幅提高模型正演运算速度,有效解决三维反演建模方法在建模过程中对模型复杂度和规模的限制,可方便构建形态复杂、不同规模的三维地质模型。并将该方法应用于湖北大冶铁矿区,构建大冶铁矿研究区三维地质模型,验证了该方法的可行性及合理性。

With the increasing difficulty of finding the shallow surface deposit and the increasing depth of resources exploration, three-dimensional modeling technology is more apparent in deep prospecting, and its accuracy directly determines the cognitive degree of geological body and metallogenic condition. For this, we put forward a set of the extraction technology of abnormal information combined with aeromagnetic data processing with three-dimensional geological modeling. Inversing the selected profile of the study area and obtaining each profile geological model, we built three-dimensional geological model of geological units by the method of profile linked, using undulating terrain three-dimensional block magnetic field forward techniques to model the three-dimensional geological model of the whole area, and obtained the forward modeling results of the whole three-dimensional geological model and the geological unit. After the comparative analysis with the test result, adding reasonable geological constraints and revising model, through adjusting for many times, we made the model maximum close to the actual situation. The model can well reflect the geological information and make minimum fitting error of observations and theoretical field, with which geologists can use the most of their experience and get more regional geological understanding. Using the thought of main block and secondary block to subdivision modeling of geological body, on the condition of ensuring the accuracy of model, the number of the total model block decreased and the multi-window and multi-geological body parallel computing method were used to improve the modeling speed, effectively solve the limitation problem of the model complexity in the process of the three-dimensional inversion modeling method, and easily form complex and different sizes three-dimensional geological model. We applied this method to the Hubei Daye area, constructed the three-dimensional geological model of Daye Iron Mine, and verified the feasibility and rationality of this method.