江西大吉山钨矿床品位概率分布型式及其地质意义

摘要

大吉山钨矿床是我国著名的大型钨多金属矿床,以外接触带石英脉型W-Mo-Bi矿体为主,兼具内接触带蚀变花岗岩型Ta-Nb-W-Be矿体,是南岭“五层楼+地下室”或“上脉下体”型钨矿床的典型代表.大吉山钨矿床品位的概率分布型式研究表明,无论是脉状矿体,还是蚀变花岗岩型矿体,WO3品位均呈现出分布范围宽、低品位频数高、高品位频数低,即接近对数正态分布的概率分布型式,这暗示其钨成矿过程均较复杂,均受多种地质作用和/或物理化学条件控制.%Dajishan tungsten deposit is a well-known large-scale tungsten polymetallic deposit in China for it is also a typical example of "five-floor + basement" or "upper veins + underneath mineralized granite" tungsten deposit,in which wolframite primary occurs in W-Mo-Bi mineralized quartz veins but also in Ta-Nb-W-Be mineralized granite.It is showed by study of grade probability distribution mode that WO3 grades are wide in range,and high frequency in low grades and low frequency in high grades,namely,approximately in a lognormal distribution mode for both ore veins and mineralized granite.It implies that their ore-forming processes are complicated and might be controlled by several geological processes and/or physiochemical conditions.