滇东北宣威一带铌矿床地质特征

Geological Characteristics of Niobium Deposits in the Xuanwei Area,Northeastern Yunnan Province

随着贵州威宁玉龙、黑石头等地铌矿床(点)的发现,结合该区域同类型铌矿床研究成果,以及本次在宣威倘塘一带所开展的矿产地质调查工作中发现的铌矿体(点),总结了滇东北宣威一带铌矿床地质特征,认为主要赋矿层位为峨眉山玄武岩顶部的铁质凝灰岩地层,受峨眉山玄武岩喷发后期剥蚀沉积成矿。含矿层具有明显的高铌低钽,并伴(共)生稀土及钪、钛等元素之特征。成矿类型初步定为玄武岩喷发后期剥蚀沉积型铌矿床。

With the discovery of Nb deposits(spots)in Yulong and Heishitou,Weining,Guizhou Province,combined with the research results of the same type of Nb deposits in this area and the Nb ore bodies(spots)discovered during the mineral geological survey in the Dangtang area of Xuanwei,this work summarized the geological characteristics of Nb deposits in the Xuanwei area of northeastern Yunnan.It is considered that the main ore-hosting strata are the iron tuff strata at the top of Emeishan basalt,which has undergone denudation and sedimentation duing the late eruption period of Emeishan basalt.The ore bearing strata are characterized by obviously high Nb and low tantalum,accompanied by(associated)rare earth elements and elements such as Sc and Ti.The metallogenic type is preliminarily classified as the late stage of erosion and deposition of niobium deposits in the late stage of basalt eruption.