【作者】 马腾飞；

【导师】 吕庆田；

【作者基本信息】 中国地质科学院 ， 固体地球物理学， 2013， 硕士

【摘要】 地下地质体三维结构、构造形态的正确认识是我们认识地质与成矿过程、指导找矿实践的重要基础,而矿集区三维地质-地球物理建模技术为了解一定深度(3km-5km)地下精细结构以及地层、岩体的空间展布关系即地下结构的“透明化”提供了可能性。论文以国家科技专项“深部矿产资源立体探测技术与实验(SinoProbe-03)"专项为依托,选择庐枞矿集区作为研究对象,通过利用研究区内的综合地质地球物理资料,以反射地震剖面、重磁数据为基础,进行矿集区三维地质地球物理建模研究,进而了解矿集区深部三维构造特征,为庐枞矿集区“第二找矿空间”提供深部认识,具有重要科学研究意义和实际意义。通过对庐枞矿集区区域地质资料、重磁场数据、反射地震剖面深入认识,并利用人机交互反演,初步实现了庐枞矿集区5km以内的地质结构“透明化”,深化了对该地区成矿、控矿结构的认识,论文取得了如下进展：本次研究提出了一种新的矿集区三维地质-地球物理建模的思路和技术流程,即通过充分理解研究区区域地质概况,深入挖掘重磁场特征,以反射地震剖面作为骨干剖面,利用全三维建模平台,首先建立骨干剖面约束的三维模型,在此基础上将该模型垂直构造走向切分成多条二维剖面,逐条修改直到完全符合地表地质形态以及对研究区的基本地质认识及物性特征,初始模型建立后,对初始模型逐条剖面进行重力反演拟合,通过人机交互进一步修正三维模型。该方法最大的优势就在于无论在三维初始模型建立过程中,还是在反演拟合过程中,都可以最大限度融合建模人员对矿集区地质地球物理特征的理解。在建模过程中,对不同时期地层划分方案进行了整合和归并,开展了物性统计研究,并确定地层及侵入岩密度作为反演拟合的基础。开展了位场分离方法试验研究,对庐枞地区重力数据采用多种不同位场分离方法求取剩余异常,最终采用高通滤波位场分离结果作为反演建模数据。对矿集区内五条地震剖面进行系统认识,分析了庐枞火山岩盆地的边界结构框架,根据地震剖面反射特征,将盆地分为南北两部分,推测平行于反射地震2线的区域性断裂是南北两部分的分界线。在地震剖面上所识别出的盆地北面下部的三叠和白垩系地层的空间展布特征,为斑岩型及矽卡岩型矿床的预测提供了目标。通过在反射地震骨干剖面约束下进行重力反演拟合,推测得到了研究区内主要的岩体深部延伸范围,以及主要隐伏岩体的空间形态。三维模型展示了庐枞盆地的精细结构,尤其是与成矿有关地层及岩体的空间展布规律,为进一步找矿工作提供了参考。更多还原

【Abstract】 Understanding of three-dimensional underground geologic structure is an important basis for recognize geology and mineralization processes.The three-dimensional geological geophysical modeling techniques provides an opportunity to understand certain depth (3km-5km) and the structure of underground formations, rock spatial distribution relations.The study as the basis of special of national science and technology projects,"Three-dimensional exploration of mineral resources in deep technical and experimental (SinoProbe-03)".Lujiang-Zongyang ore district was selected as the study area in this paper, we using integrated geological and geophysical data as the basis for ore district dimensional modeling in order to understand deep three-dimensional structural characteristics of ore district.In this paper the geological data, gravity and magnetic data, seismic reflection profiles of Lujiang-Zongyang ore district had been used to construct the3D geological and geophysical model. The initial realization of Lujiang-Zongyang ore district5km depth geological structure had been deepened the region mineralization, ore understanding of the structure and some progress had been made in this study:This study presents appropriate technical processes for three-dimensional geological and geophysical modeling for Lujiang-Zongyang ore district. Firstly, the seismic profiles are prepared for construct the initial3D model, then the initial model was cut into the two-dimensional sections modified one by one until full compliance with the surface geology of the study area. Then the initial model for gravity inversion fitting profiles one by one, through further amendments interactive3D models. The biggest advantage of this method is that one can maximize the integration understand of modelling ore district geological and geophysical characteristics.In the modelling process, the different periods were integrated stratigraphic division and merging programs, carried out statistical studies the physical properties and determine the stratigraphic and intrusive rocks density inversion fitting as the basis. Various regional-residual separation methods had been used to carry out and finally high-pass filtering been choosed to the final separation results as potential field inversion modeling data. According to interpretation of five seismic profiles acrossed Lujiang-Zongyang ore district, the volcanic basin boundary structural framework based on seismic reflection characteristics was divided into two parts, north and south, suggesting that two lines parallel to the reflection seismic fault is the north-south regional dividing line between the two parts. The distribution characteristics of seismic profiles contribute to provide information to target porphyry and skarn deposits.Finally, the deformation range of rock in depth and key fault strike had been revealed by using seismic reflection profiles under gravity inversion constrained fitting inversion. The3D geological and geophysical model of Lujiang-Zongyang shows the3D structure of the basin, particularly related to mineralization of rock formations and spatial distribution law for further prospecting work.更多还原