鲁西东平—汶上成矿带航磁异常特征与找矿预测

发布时间：2018-07-13 21:31

【摘要】：东平-汶上成矿带位于华北板块东南缘的鲁西隆起区。该地区具备较好的成矿条件。全省大、中型铁矿床几乎都分布于鲁西,而东平-汶上成矿带为该区域的重要铁矿产地,张保庄、彭集、李官集等10余处大、中型铁矿均位于该矿带,具有极高的经济和研究价值。但该区区域沉积层覆盖厚、构造复杂,不利于进一步寻找具有开发效益的铁矿预测区。本文以鲁豫皖相邻地区航磁调查项目为依托,在搜集前人研究成果和理论基础之上,进而以航空磁测数据为主要依据,同时开展野外地面查证工作。本文通过处理高精度航磁数据发现,研究区整体位于正负变化磁异常带内,异常众多,磁场面貌复杂,异常走向以NW为主。多数正磁异常由泰山岩群山草峪组磁性变质岩引起,部分高值为矿致异常,负磁异常多数为应具有较厚第四系覆盖的坳陷区的反映。以航磁ΔT剖面平面图、等值线平面图、化极图、化极垂向一次导数图、上延图为主,划分三个级别断裂共27条以及磁性变质岩带若干。通过研究认为,与成矿相关的变质岩带向北可延伸至东阿县徐楼地区,北部被东阿断裂截断,向西可以延伸到梁山县南部地区,对覆盖区找矿具有重要意义。将航磁信息结合以往地质资料进行对比研究,在研究区内的提取异常174个,并对异常进行判别、分类。针对区内典型异常选择2.5D反演拟合、对重点找矿异常作了定量解释,确定磁性体的空间展布形态、埋深及磁性强弱等参数。最后根据航磁所反映的断裂构造及岩性分布特征,以局部异常解释为基础,结合已知矿床的空间分布及成矿规律分析成矿条件建立找矿标志,对重要矿种开展地、物等综合信息叠加分析和进行找矿预测区圈定。本次研究以航磁信息为基础,结合前人研究成果将东平-汶上成矿带范围进行“北延西扩”;针对5处已知矿异常和推断矿异常进行了资源量估算;建立研究区内东平式沉积变质型铁矿找矿标志;圈定三个级别的预测区8个,以期对未来的找矿勘查工作提供参考。
[Abstract]:Dongping-Wenshang metallogenic belt is located in the Luxi uplift of the southeastern margin of the North China plate. This area has better metallogenic conditions. The large and medium iron ore deposits in the whole province are almost distributed in the west of Shandong Province, and the Dongping-Wenshang metallogenic belt is an important place of iron ore production in this area. There are more than 10 large and medium-sized iron ore deposits, such as Zhang Baozhuang, Pengji, Li Guanji, etc. It is of great economic and research value. However, the sedimentary layer in this area is thick and the structure is complex, which is not conducive to the further exploration of the iron ore prediction area with development benefit. Based on the aeromagnetic survey project in the adjacent areas of Shandong, Henan and Anhui provinces, and on the basis of the previous research results and theories, and taking aeromagnetic survey data as the main basis, the field ground investigation work is carried out in this paper. By processing high precision aeromagnetic data, it is found that the study area is located in the positive and negative variation magnetic anomaly zone, with numerous anomalies, complex magnetic field features and NW anomaly strike. Most of the positive magnetic anomalies are caused by the magnetic metamorphic rocks of the Shancaoyu formation of Taishan rock group, some of the high values are mineral-induced anomalies, and the negative magnetic anomalies are mostly reflected by the depression areas covered by the thicker Quaternary system. The plane map of aeromagnetic 螖 T section, the plan of isoline, the vertical derivative diagram of the metamorphic pole and the upward extension diagram are mainly divided into 27 faults of three grades and some magnetic metamorphic rock belts. The study shows that the metamorphic rock belt related to metallogenesis can be extended north to Xulou area of Donga County, the north is cut off by Donga fault, and the westward extension can be extended to the southern area of Liangshan County, which is of great significance for prospecting in overlying area. Combining aeromagnetic information with previous geological data, 174 anomalies are extracted in the study area, and the anomalies are distinguished and classified. According to the typical anomalies in the region, 2.5D inversion fitting is selected, and the key ore prospecting anomalies are quantitatively interpreted to determine the spatial distribution shape, buried depth and magnetic strength of magnetic bodies. Finally, according to the characteristics of fault structure and lithologic distribution reflected by aeromagnetic field, based on the interpretation of local anomalies, combined with the spatial distribution of known deposits and the metallogenic law, the ore-prospecting criteria are established, and the important ore types are developed. The comprehensive information such as material and other information are superimposed and delineated for prospecting and prediction areas. Based on aeromagnetic information and combined with previous research results, the paper expands the area of Dongping-Wenshang metallogenic belt from north to west, and estimates the resource quantity of five known ore anomalies and inferred ore anomalies. The ore-prospecting markers of Dongping type sedimentary metamorphic iron ore deposits in the study area are established and 8 prediction areas of three grades are delineated in order to provide reference for the future prospecting and exploration work.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P612;P631.222

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