摘要
稀有金属资源是我国各类高新技术产业的重中之重,为了摆脱这些资源被其他国家的限制,加强稀有金属找矿是我们地质工作者目前需加紧解决的问题,与稀有金属矿化密切相关的伟晶岩是我们需要重点关注的类型。伟晶岩稀有金属矿床中的矿物复杂多样,主要是由于复杂的岩浆期后热液作用,以及不同阶段成矿流体成分和温度的差异导致的。主要有两种模式:1、花岗质岩浆演化后期富挥发分(H2O、F等)的残余熔体沿裂隙贯入到相对封闭的围岩中结晶而成赋矿伟晶岩;2、超变质的深熔作用或选择重熔作用形成的深熔流体对固态岩石发生重结晶作用及交代作用或沿构造裂隙贯入而形成伟晶岩脉。在成矿地质背景上,伟晶岩型稀有金属矿床的形成通常与造山作用密切相关。桂东南地区地处华南板块西南部,正处于华夏地块和扬子地块的交接部位,碰撞造山作用导致的构造–岩浆作用活跃,是广西乃至华南地区一个重要的有色金属成矿带,同时也是一个重要的新兴矿产成矿区。稀有金属广泛地分布在桂东南地区,此类矿种的发育与博白、北流、容县一带大面积出露的高度演化的花岗岩体中分异出来的伟晶岩有关,出现伟晶岩型稀有金属矿化。主要赋存于桂南晚志留世宁潭超单元及其外接触带中。区内伟晶岩发育集中区主要有4处,1、桂东地区昙容伟晶岩群,2、云开地区石垌伟晶岩群,3、云开地区双旺伟晶岩群,4、云开地区北流六靖伟晶岩群。可以预见,这些伟晶岩中蕴藏了丰富的稀有金属资源,亟待我们去勘察开发。
Rare metal resources are the top priority of various high-tech industries in China. In order to break away from the constraints of these resources by other countries, strengthening the exploration of rare metals is a problem that our geologists need to urgently address. Pegmatite, which is closely related to rare metal mineralization, is a type that we need to focus on. The complexity and diversity of minerals in pegmatite rare metal deposits are mainly due to complex post magmatic hydrothermal processes, as well as differences in the composition and temperature of ore-forming fluids at different stages. There are two main modes: 1. The residual melt rich in volatiles (H2O, F, etc.) in the late stage of the evolution of granitic magma penetrates along the fractures into relatively closed surrounding rocks and crystallizes into ore-bearing pegmatite;2. Hypermetamorphic deep melting or selective remelting formed deep melting fluids recrystallize and metasomatize solid rocks or penetrate along structural fractures to form pegmatite veins. In the metallogenic geological setting, the formation of pegmatite type rare metal deposits is usually closely related to orogeny. Southeast Guangxi is located in the southwest of the South China Plate, at the junction of the Cathaysian and Yangtze blocks. Tectonic magmatism caused by collision orogeny is active, making it an important nonferrous metal metallogenic belt in Guangxi and even South China, as well as an important emerging mineral metallogenic area. Rare metals are widely distributed in southeastern Guangxi, and the development of such minerals is related to pegmatite differentiated from highly evolved granite outcrops in a large area in the areas of Bobai, Beiliu, and Rongxian, resulting in pegmatite type rare metal mineralization. It mainly occurs in the Late Silurian Ningtansuperunit and its outer contact zone in southern Guangxi. There are mainly four areas where pegmatite development is concentrated, namely, the Tanrong pegmatite group in Eastern Guangxi, the Shido
出处
《地球科学前沿(汉斯)》
2023年第5期506-515,共10页
Advances in Geosciences