【摘要】 滁州褶冲亚带是位于长江中下游地区重要的铜金成矿区带,以西侧黄破断裂与东侧滁河断裂为边界,深入了解本区的深部地质特征对于该区隐伏铜金矿床的矿产勘查工作具有重要意义。本文结合实测地质剖面,通过解译三条与本区主要构造方向垂直的重力、磁法和音频大地电磁测深(AMT)综合剖面,提取深部构造信息并进行解译。地质体深部解译主要依据电阻率的变化、?T化极磁异常、布格重力异常的曲线特征和实测剖面进行综合推断,获得以下结论和认识:(1)黄破断裂两侧存在较大规模的隐伏断层,在不同地区主断面的深部形态和逆冲推覆距离不同;(2)滁河主断裂倾向北西,倾角60°～70°,形态较为稳定,在苏家湾-夏阁地区除主断裂外,南东侧还发育较大规模的反冲断层;(3)区域内隐伏岩体顶界隐伏深度普遍在0.5～1.5km之间,其围岩主要为震旦系和寒武系的碳酸盐岩;(4)黄破断裂主断面西侧震旦纪地层内次级断裂较多,地层产状变化较大;南东侧深部的相对低阻特征指示深部的褶皱变形更加强烈。总体来说,重力、磁法和AMT综合剖面对该区深部构造形态具有良好的探测效果,结合区域成矿模型,推断隐伏岩体与碳酸盐岩地层的接触带部位是矽卡岩型铜金矿床的有利成矿部位,推荐以高精度重磁方法为主继续开展找矿工作;隐伏断裂形成的构造破碎带以及其与褶皱构造相交的部位是微细浸染型金矿的有利成矿位置,建议先明确隐伏次级断裂的空间位置以间接找矿。更多还原

【Abstract】 The Chuzhou fold thrust sub-belt is an important Cu-Au metallogenic zone in the Middle-Lower Yangtze Metallogenic Belt, which is bounded by the Huangpo fault in the west and the Chuhe fault in the east. A thorough understanding of the geological characteristics of this area will shed light on the exploration of concealed Cu-Au deposits. Combined with the geological background, the deep geological structures were inferred through interpretation of three gravity-magnetic-AMT composite profiles perpendicular to the mainly NE trend structures in this area. The deep geological bodies are interpreted mainly on the basis of the changes of resistivity, characteristics of reduction-to-the-pole of magnetic anomalies and bouguer gravity anomalies, as well as the features of outcrops.Macroscopically, the Huangpo fault has a relatively long nappe distance and dip angles varying from 70°, to 30° and then to 70° from shallow to deep. Interestingly, a large concealed fault is detected about 8 km to the east the main fault,which is NW inclining with a dipping angle of 50° – 60°. In the Sujiawan-Xiage area, however, the Huangpo fault dips 40°– 70° from shallow to deep, with a relatively short nappe distance. On its west side, a large concealed fault develops within the Cambrian strata, NW inclining with a dipping angle of 60° – 80°. The Chuhe fault mainly dives NW direction with a dip angle of 50° – 70°. In the Sujiawan-Xiage area, particularly, at a distance of 4 – 6 km to the SE of its main fault section, there is a concealed fault dipping SE with a dip angle of 60° – 70°.The buried depth of the intrusive rock masses is generally between 0.5 km and 1.5 km, with the Sinian and Cambrian carbonate strata as the main wall rocks. The developing subordinate faults within the Sinian strata, on the west side of the main section of the Huangpo fault, led to the significant occurrence changes of the strata. On the other hand, fold structures developed in the Cambrian carbonate strata on the southeast side of the Huangpo fault, in particular, are characterized by intensive folding deformation in the deep part as exhibited by the relatively low resistance.In general, the magnetic-gravity-AMT integrated profile has a good detection efficacy on deep geological structures in this area, and high-precision gravity and magnetic methods are recommended for future exploration. Combined with the regional metallogenic model, following favorable ore-forming zones can be inferred: 1) the contact zones between the concealed intrusive rock masses and wall rocks are favorable for skarn copper-gold deposits prospecting; 2) the fracture zones as well as in-between faults and fold-developed strata are favorable for searching of fine disseminated gold deposits.更多还原