内蒙古中西部钼多金属矿床地质特征及其动力学背景

Geological Features and Geodynamic Background of the Molybdenum Polymetallic Deposits in Central-Western Inner Mongolia

本文首次对内蒙古中西部白乃庙铜-钼-金矿床、大苏计钼矿床、西沙德盖钼矿床、柳坝沟金-钼矿床、哈达门沟金-钼矿床、查干花钼-钨矿床和流沙山钼-金矿床的产出环境、地质特征、成因类型和时空分布特点进行了简要总结,对成矿作用与构造-岩浆活动的关系进行了概略性论述。柳坝沟、哈达门沟和白乃庙矿床均在前寒武纪变质岩地层中产出,大苏计、查干花、西沙德盖和流沙山矿床直接产于海西-印支期中酸性侵入岩中,尽管上述矿床在产出环境和地理位置上存在有一定差别,但是它们均与花岗岩类侵入岩体(或岩脉)具有密切的空间分布关系,属与中酸性侵入岩有关的钼多金属矿床。另外,根据矿床(点)的空间分布特点,可划分出5个钼多金属矿化集中区:即大苏计-明星沟钼矿化集中区、白乃庙-谷那乌苏铜-钼-金矿化集中区、哈达门沟-沙德盖金-钼矿化集中区、马尼图-查干花钼-铋-钨矿化集中区和流沙山-黑鹰山钼-金-铁矿化集中区。研究结果表明,成矿作用与板块消减、碰撞和缝合过程中所诱发的构造-岩浆事件密切相关,是地壳特定演化阶段构造-岩浆活动的产物。

A series of molybdenum or molybdenum polymetallic deposits have been discovered in central and western Inner Mongolia recent years,such as the Bainaimiao Cu（Mo,Au） deposit in Siziwangqi county,Dasuji Mo deposit in Zhuozi county,Xishadegai Mo deposit in Wulateqianqi county,Liubagou and Hadamengou Au（Mo） deposit in Baotou city,Chaganhua Mo（W） deposit in Wulatehouqi county,Liushashan Mo（Au） deposit in Ejinaqi county.These findings provide broad prospects for prospecting molybdenum or molybdenum polymetallic ore deposits in these areas.They have also broaden exploration visions and added new research contents for geological scholars.In this paper we make a preliminary summary of the geological background,geological features,genetic types,spatial-temporal distribution characteristics and evolution of mineralization of these deposits for the first time,and briefly discussed the relationship between molybdenum,copper-molybdenum-gold,molybdenum-bismuth-tungsten,molybdenum-gold mineralization and tectonic-magmatic activity.The Liubagou and Hadamengou gold-molybdenum deposits,and Bainaimiao copper-molybdenum-gold deposits occurred in the Archean,Proterozoic metamorphic rock formation,whereas the Xishadegai molybdenum deposit,Dasuji molybdenum deposit,Chaganhua molybdenum-tungsten deposit,and Liushashan molybdenum-gold deposit respectively appeared in the Hercynian-Indonisian granite.Although,geological settings and geographical locations of these deposits have some differences,they are closely related to granitoid intrusions （dyke） in space,belong to molybdenum or molybdenum polymetallic deposits related to the intermediate-acidic hypabyssal intrusive rocks （porphyry） or plutonic intrusive rocks.In addition,according to the spatial distribution features,these deposits （occurrences） can be divided into five molybdenum or molybdenum polymetallic mineralized concentration areas in the study region：They are the Dasuji-Mingxinggou molybdenum concentration area,Bainaimiao-Gunawusu Copper-molybdenum-gold mineralized concentration area,Hadamengou-Sadegai gold-molybdenum mineralized concentration area,Manitu-Chaganhua molybdenum-bismuth-tungsten mineralized concentration area and Liushashan-Heiyingshan molybdenum-gold mineralized concentration area.The formation of these molybdenum polymetallic deposits is closely related to tectonic-magmatic events induced by the plate subduction,collision and suturing,and the deposits are the products of crustal tectonic-magmatic activities at specific evolutionary stages.