江西大吉山钨矿床品位概率分布型式及其地质意义

Grade Probability Distribution Modes and Their Implication of Dajishan Tungsten Deposit

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,WO_3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 alsoa typical example of ＂five-floor ＋ basement＂ or ＂upper veins ＋ underneath mineralized granite＂ tungsten deposit, inwhich wolframite primary occurs in W-Mo -Bi mineralized quartz veins but also in Ta -Nb -W-Be mineralizedgranite. It is showed by study of grade probability distribution mode that WO3 grades are wide in range, and highfrequency in low grades and low frequency in high grades, namely, approximately in a lognormal distribution modefor both ore veins and mineralized granite. It implies that their ore-forming processes are complicated and might becontrolled by several geological processes and/or physiochemical conditions.