安徽铜陵—繁昌地区深部成岩成矿作用探讨——来自综合地球物理探测的制约  

Diagenesis and mineralization in Tongling and Fanchang areas,Anhui Province:Constrains from the integrated geophysical exploration study

作　　者：王云云[1] 兰学毅 郭冬[1] 张莎莎[1] 丁文祥 陶龙[1] 张慧杰 张媛媛 叶林[1] 尤淼[1] WANG Yun-Yun;LAN Xue-Yi;GUO Dong;ZHANG Sha-Sha;DING Wen-Xiang;TAO Long;ZHANG Hui-Jie;ZHANG Yuan-Yuan;YE Lin;YOU Miao(Geological Exploration Technology Institute of Anhui Province,Hefei 230001,China)

机构地区：[1]安徽省勘查技术院,安徽合肥230001

出　　处：《物探与化探》2021年第3期590-600,共11页Geophysical and Geochemical Exploration

基　　金：安徽省自然科学基金青年项目(2008085QD177);安徽省公益性地质项目“南陵—宣城矿集区三维综合地球物理探测”(2018⁃g⁃1⁃4)。

摘　　要：长江中下游成矿带断凹区深部是否发育类似断隆区的铜金矿化引起了广泛关注。本文基于穿过铜陵断隆区和繁昌断凹区的地球物理剖面,利用重磁电震综合地球物理探测方法,厘定了铜陵和繁昌地区深部地质结构、控岩控矿构造和岩浆系统的空间分布形态,对比分析表明两地区深部岩体的岩性、侵入高度和范围明显不同,繁昌地区深部岩体较铜陵岩体偏酸性,且侵位深度浅。断裂的作用也明显不同,铜陵地区的断裂仅起到控制岩体浅部定位的作用,而繁昌盆地边界断裂则是盆地内岩浆上升的通道。同时铜陵地区岩体具有"一母多胎"的特征,衍生出来自同一岩浆房的多个岩枝或岩株,这直接表明了铜陵地区不同类型的岩浆岩为同一岩浆源区演化的产物,不同的演化程度可能是导致它们矿化差异的原因之一。本次研究运用综合地球物理探测方法探讨了铜陵和繁昌地区成岩成矿作用差异,从地球物理的角度解释了为何繁昌断凹区成矿特点不同于铜陵断隆区和繁昌盆地深部不存在"第二个铜陵"的原因,进一步深化了对长江中下游成矿带铜铁成矿作用规律的认识,为今后的找矿勘探提供了理论支持。In the Middle-Lower Yangtze River metallogenic belt, the possibility of the development of copper-gold mineralization similar to things of the fault-uplift area in the depth of volcanic basin has attracted extensive attention. Based on the geophysical profile through the Tongling fault-uplift area and Fanchang volcanic basin and using integrated geophysical exploration methods, the authors identified the deep geological structure, rock and ore-controlling structure and the distribution of intrusions. The comparative study shows that the lithology, height and distribution of intrusions are different in Tongling and Fanchang area, and the intrusions in Fanchang is more felsic and shallow than those in Tongling. The faults in Tongling area only control the shallow location of intrusions, while the boundary faults in Fanchang basin are the channels for magma rising. The intrusion in Tongling area is characterized by "one mother and multiple offspring" and different intrusive branches or strains derived from the same magma chamber, which directly proves that different types of intrusive rocks in Tongling area are the products of the evolution of the same magma source region, and different degrees of evolution may be one of the reasons for their different kinds of mineralization. In this study, the authors used integrated geophysical exploration methods to discuss the difference of diagenesis and mineralization between Tongling fault-uplift area and Fanchang volcanic basin and explain the reason why only small iron mineralization exists in Fanchang region while large copper(-gold) deposit occurs in Tongling region. In addition, large-scale intrusion of granitic magma in the depth of Fanchang region indicates that there is no "second Tongling" in the depth of the Fanchang volcanic basin. These results further deepen the understanding of the regularity of copper and iron mineralization in the Middle and Lower Yangtze River metallogenic belt and provide theoretical support for ore prospecting and exploration in the future

关 键 词：铜陵断隆区 繁昌断凹区 综合地球物理探测 控岩控矿构造 深部地质结构 

分 类 号：P631[天文地球—地质矿产勘探]