福建永定大坪花岗斑岩体的铌钽富集特征研究

发布时间：2018-08-12 16:02

【摘要】：福建大坪花岗斑岩体位于永定县城南部的大石凹—蓝地火山喷发盆地,具斑状结构,基质呈霏细结构、细-微粒结构。文章运用电子探针(EMPA)和激光剥蚀电感耦合等离子体质谱仪(LA-ICP-MS)等技术,对大坪岩体ZK10001钻孔中不同深度的岩石样品进行了矿物和岩石化学分析。分析结果表明,大坪岩体岩性为黑鳞云母碱长花岗斑岩,属于过铝质钙碱性花岗岩,具有较高的分异演化程度,Nb2O5和Ta2O5含量达到了花岗岩型稀有金属矿床的工业品位。铌钽矿物主要与黄玉、萤石的集合体呈稀疏浸染状、星点状产于基质间隙内,其次以星点状存在于石英和长石斑晶中。矿石矿物赋存特征与宜春钽铌矿床类似,可能具有一定的可选性和经济价值。大坪岩体的铌钽富集特征不同于斑岩型铜、钼矿床,与花岗岩型铌钽矿床也存在较大的差别,铌钽的富集过程经历了深部斑晶阶段和浅部基质阶段两阶段岩浆结晶分异作用,F等挥发分促进了铌钽在结晶残余岩浆中富集,在基质间隙间沉淀。大坪矿化岩体的发现暗示斑岩型铌钽矿床存在的可能性。
[Abstract]:The Daping granitic porphyry in Fujian Province is located in the Dashiao-Landi volcanic eruption basin in the south of Yongding County. Using electron probe (EMPA) and laser etching inductively coupled plasma mass spectrometer (LA-ICP-MS) techniques, the mineral and petrochemical analysis of rock samples with different depths in the ZK10001 borehole of Daping rock body has been carried out in this paper. The results show that the lithology of the Daping rock body is biotite alkali-feldspar porphyry, belongs to peraluminous calc-alkaline granite, and has higher differentiation and evolution degree. The content of NB _ 2O _ 5 and Ta2O5 has reached the industrial grade of granitic rare metal deposit. Niobium and tantalum minerals are mainly associated with topaz, fluorite aggregates are sparsely disseminated, star dots occur in matrix gaps, and then star dots are found in quartz and feldspar porphyry crystals. The occurrence characteristics of ore minerals are similar to those of Yichun tantalum-niobium deposit, which may be of certain selectivity and economic value. The characteristics of niobium and tantalum enrichment in Daping rock body are different from those of porphyry copper and molybdenum deposits, and are also different from granite type niobium tantalum deposits. The enrichment process of niobium and tantalum has experienced two stages of deep porphyry phase and shallow matrix stage. The volatiles such as F promoted the enrichment of niobium and tantalum in the residual magma and precipitated between the matrix gaps. The discovery of the Daping mineralized rock mass suggests the possibility of the existence of porphyry niobium tantalum deposits.
【作者单位】：中国地质科学院矿产资源研究所;中国冶金地质总局第二地质勘察院;国家地质实验测试中心;
【基金】：国家重点研发项目(编号:2016YFC0600204) 国家自然科学基金项目(编号:41372088) 中央级公益性科研院所基本科研业务费专项基金(编号:K1409) 中国地质调查局地质调查项目(编号:DD20160056,DD20160055)联合资助
【分类号】：P618.79;P618.86

【相似文献】