基于重磁联合反演的麻姑山地区深部地质结构解析研究

A study on deep geological structure analysis of Magushan area based on gravity and magnetic joint inversion

近年来,随着茶亭铜金矿床等多处新矿床被相继发现,南陵—宣城地区有望成为长江中下游成矿带的新矿集区。其南部的麻姑山地区发育有麻姑山铜矿床,但由于本区第四系地层覆盖面积大、地质勘探程度浅,其深部地质结构尚不清晰,影响了本区隐伏矿床地质找矿工作的深入开展。本文基于地球物理重、磁数据,以已知地质填图和勘探数据为约束,对麻姑山地区深部地质结构进行了2.5D联合反演和深入解析;同时,结合三维地质建模技术和三维地球物理正演方法对解译结果进行了修正和厘定。研究结果表明,三维地质建模技术和三维地球物理正演方法可为2.5D重磁联合反演结果提供修正依据和手段;解析结果能够较好的阐明麻姑山地区的深部地质结构,结合找矿预测条件,能够圈定隐伏找矿预测靶区,可进一步为找矿工作提供更多参考信息。

In recent years, with the discovery of many new deposits such as Chating copper-gold deposits, Nanling-Xuancheng area is expected to be a new ore district in the middle and lower reaches of the Yangtze river. Magushan copper deposit is developed in Magushan area of southern Nanling-Xuancheng, but due to the large quaternary strata coverage and shallow geological exploration, its deep geological structure is not clear, which has affected the deep exploration of hidden deposits in this area. Based on geophysical gravity and magnetic data, and constrained by known geological mapping and exploration data, this paper conducted 2.5D joint inversion and in-depth analysis of the deep geological structure of Magushan area. At the same time, the interpretation results are corrected and determined by combining the 3D geological modeling technology and the 3D geophysical forward modeling method. The results show that the 3D geological modeling technology and the 3D geophysical forward modeling method can provide the basis and means for correcting the 2.5D gravity and magnetic joint inversion results. The analytical results can better elucidate the deep geological structure of Magushan area, and combined with the analytical results and the ore-prospecting prediction conditions, it can delineate the hidden ore-prospecting prediction target area and provide more reference information for ore-prospecting work.