摘要:
四川省牦牛坪矿床是全球第三大稀土矿床(仅次于我国白云鄂博和美国芒廷帕斯),近期在其外围取得了找矿新突破——在龙家沟一带第四系(厚达50 m以上)之下探获了隐伏的两类厚大稀土矿体,第一类为氟碳铈矿-霓辉石-莹石-重晶石型,第二类为氟碳铈矿-萤石-重晶石-方解石型。其中,氟碳铈矿-萤石-重晶石-方解石型矿脉整体厚度(视厚度)超过100 m,稀土平均品位4.6%。经多晶X射线衍射分析,此类矿石主要由方解石(40%~75%)、萤石(25%~58%)、重晶石(5%~25%)和氟碳铈矿(1%~16%)组成。根据矿石的结构、构造及矿物组成,可将其形成分为早、晚两个阶段: 早阶段矿石主要呈中粗粒结构,块状构造、斑杂状构造; 晚阶段矿石呈中细粒角砾状构造、流动构造。此类品位高、易采选的新型矿体的发现,是新一轮找矿突破战略行动实施以来在稀土矿产勘查方面取得的重要突破。建议在牦牛坪矿床及其外围进一步开展寻找氟碳铈矿-萤石-重晶石-方解石脉型稀土矿体的地质找矿工作。
Abstract:
Maoniuping deposit is the third largest rare earth element(REE) deposit in the world after Bayan Obo in China and Mountain Pass in the United States. Recently, a new ore-prospecting break was made in the periphery of Maoniuping deposit, and two types of thick and rich concealed rare earth ore bodies have been discovered under Quaternary sediments (more than 50 m thick) in Longjiagou area. The first type is the bastnaesite-aegirene-fluorite-barite, and the second type is the bastnaesite-fluorite-barite-calcite. The total thickness (apparent thickness) of the bastnaesite-fluorite-barite-calcite type vein exceeds 100 m, and the average REE grade is 4.6%. The X-ray diffraction analysis result shows that the ore was mainly composed of calcite (40%~75%), fluorite (25%~58%), barite (5%~25%) and bastnaesite (1%~16%). Based on the texture, structure and mineral composition of the ore, the authors divided its formation process into two stages. The ore in the early stage was mainly medium coarse granular structure, and massive structure and taxitic structure, while the ore in the late stage was medium-fine grain brecciform structure and flow structure. The discovery of this new type of ore body with high-grade, easy to mining and beneficiation is an important breakthrough in rare earth mineral exploration since the implementation of the new round of prospecting breakthrough strategy. It is suggested that further geological prospecting for REE ore of bastnaesite-fluorite- barite-calcite type should be undertaken in Maoniuping mining area and its periphery.
下载: