摘要
内蒙古牙克石地区近年来发现了岩山中型钼矿床。赋矿围岩以元古界兴华渡口群为主,其次为燕山期花岗斑岩隐伏岩体。该岩体自边部至中心,大致呈石英斑岩-花岗斑岩-花岗闪长岩相变的特点,U-Pb年龄分别为124±1 Ma、127±2 Ma、124±1 Ma。辉钼矿主要以石英(碳酸盐-萤石)辉钼矿脉、长石石英辉钼矿脉、碳酸盐(-萤石)辉钼矿脉的形式存在于围岩中,切穿岩体与地层的接触带。以兴华渡口群为围岩的辉钼矿Re-Os年龄为125.2±1.7 Ma,以花岗斑岩为围岩的辉钼矿Re-Os年龄为126.6±1.8 Ma,长石石英脉中辉钼矿Re-Os年龄为125.3±1.8 Ma。根据矿体与围岩的相互关系及年龄测定结果,无论从时间上和空间上成矿均与燕山期花岗斑岩的侵入密切相关,热液充填活动明显,属岩浆热液型矿床。
In recent years,a moderiate-size molybdenum deposit was discovered in the Yanshan area,Yakeshi,Inner Mongolia. Its host rocks are primarily the Proterozoic Xinhuadukou Group,and secondly the concealed rock of the Yanshan-period granite porphyry. These rocks exhibit the characteristics of quartz porphyry and granite porphyry-granite diorite phase transition from the edge to the center with U-pb ages 124 ± 1 Ma,127 ± 2 Ma,and 124 ±1 Ma,respectively. Molybdenite ore appears in the quartz( carbonate-fluorite) vein,feldspar quartz vein,and carbonate( fluorite) vein,which cut through the contact zone between the rock and strata. The Xinghuadukou Group molybdenite Re-Os age for the surrounding rock is 125. 2 ± 1. 7 Ma,the granite-porphyry molybdenite Re-Os age of surrounding rock is 126. 6 ± 1. 8 Ma,and feldspar quartz veins molybdenite Re-Os age is 125. 3 ± 1. 8 Ma.According to the dating results and relationship between the ore body and surrounding rock,mineralization was closely related to the Yanshan-period granite porphyry in both time and space. The obvious hydrothermal filling activity suggests the type of the magmatic hydrothermal deposit.
出处
《地质与勘探》
CAS
CSCD
北大核心
2015年第1期45-52,共8页
Geology and Exploration
