摘要
介绍了近年来在四川甲基卡稀土金属矿区外围北部发现的新三号(X03号)超大型矿脉特征,通过对ZK1101钻孔岩心的详细研究,初步查明:甲基卡新三号脉的稀有金属矿化以锂为主,共伴生有铍、铌钽、锡等金属,在顶底板围岩中存在红柱石矿化和铯的金属矿化;金属矿物主要是锂辉石,少量绿柱石、铌钽铁矿等;矿石类型主要有伟晶型、细晶型和混合型;矿化分带不太发育,主要是由于多阶段的交代和充填结晶作用反复进行而使得结构带复杂化;围岩蚀变主要是红柱石化、堇青石化、电气石化等。综合分析,甲基卡新三号脉在成因上与新疆的可可托海三号脉既有共性也有区别:前者在成因上受控于甲基卡热-变质-岩浆穹窿构造,后者主要定位于辉长角闪岩内部的封闭环境。
The largest lithium-bearing pegmatite reported in Jiajika is in the eastern part of Tibet plateau,which is also the largest spodumene deposit in Asia. With the newly discovery of X03 Li-bearing pegmatite in Jiajika ore field,the total lithium reserves are generally larger than that of Greenbushes in Australia and rank at the top of the world. By the study of the cores from ZK1101 drilling of X03 pegmatite,it is clear that X03 pegmatite is featured by Li-dorminated mineralization,associated with beryllium,niobium,tantalum and tin,with the presence of andalusite and cesium mineralization in the hanging wall and foot wall. The major economic minerals include spodumene and a small amount of beryl,niobium tantalite. Rare metal ores can be divided into three types： the main types of pegmatite type,fine grain type and mixed type. Mineralization zoning is not very developed,mainly due to the multi-stage metasomatism and filling crystallization repeatedly and makes the structure complicated. Wall rock alteration is featured by tourmalinization aorund the pegmatite and in the andalusite and cordierite hornfels replaced by sericite and others. In general,comparing with the No. 3 vein in Keketuohai of Xinjiang and Li-bearing pegmatites in Greenbushes in Australia,the X03 super-large Li-bearing pegmatite in Jiajiaka is formed by infill and metasomatism of magma-fluids originated from granitic magma chamber,trapped with the thermal-metamorphism-magmatic dome,while the latter mainly concentrated within the enclosing metamorphic rocks of hornblendite.
出处
《桂林理工大学学报》
CAS
北大核心
2016年第1期50-59,共10页
Journal of Guilin University of Technology
基金
中国地质调查局项目(12120114039701,12120114039601)
关键词
稀有金属
矿化特点
矿石组构
锂辉石
新三号脉
甲基卡
rare metal
mineralization characteristics
fabric of ores
spodumene
X03 pegmatite vein
Jiajika
