中国东北钼矿床地质

Geology of the Mo Deposits in Northeast China

中国东北地区是中亚造山带和环太平洋构造带叠加的区域,成矿作用复杂而强烈。系统总结了东北地区的钼矿床勘查和研究进展,形成如下主要认识:1)研究区已发现3个超大型、18个大型等70余处钼矿床,探明资源量仅次于东秦岭钼矿带;2)矿床成因类型主要为斑岩型(含爆破角砾岩型)、矽卡岩型,次为热液脉型;3)成矿岩浆岩多为高硅富钾钙碱性的I型花岗岩,岩浆活动具有多期多阶段性;4)钼矿床集中分布在华北克拉通北缘、南大兴安岭、北大兴安岭和吉黑褶皱带等4个地区;5)与岩浆活动的多期多阶段性相一致,钼矿化具有多期多阶段性,但中生代最为重要,并集中在250～210、190～160和150～110 Ma等3个高峰期;6)钼矿床的辉钼矿Re含量变化较大,总体较低,显示成矿物质来源复杂,但以壳源为主;7)成矿时代越老,辉钼矿Re含量越高,Cu/Mo储量比越大;8)钼矿床主要形成于增生造山和大陆碰撞造山(含后碰撞)两种构造背景,单钼矿床始现于三叠纪,只形成于大陆碰撞造山体制。

The Northeast（NE） China is located in the combining area of the Central Asian orogenic belt and the circum-pacific orogenic belt,accommodating intensive and complicated mineralizations.The authors summarizes the progresses in exploration and geological research of the Mo deposits in the area,and draws out several conclusions as below： 1）More than seventy Mo deposits have been discovered in NE China,including three world-class giant and eighteen large deposits,with total resource being next to the eastern Qinling Mo belt;2）The main genetic types are Mo-bearing porphyry（including explosive breccia pipe） and skarn,and minor of hydrothermal vein;3）The Mo-associated intrusions are generally Si-and K-enriched calc-alkaline I-type granites,and have been formed by multi-episodic and multistage magmatism;4）The Mo deposits are concentrated in regions： the northern margin of North China craton,the southern Great Hinggan Range,the northern Great Hinggan Range and the Ji-Hei fold belt;5）The Mo deposits were formed in multi-episodic and multistage events coinciding magmatic activities,but the majority were formed in Mesozoic,with three peak-mineralization pulses at 250-210,190-160 and 150-110 Ma,respectively;6）The Re contents in molybdenites from the Mo deposits are widely variable and generaly low,indicating that the metal sources vary from mantle to crust,but mainly from continental crust;7）The Re contents in molybdenites and the reserve ratio of Cu/Mo increase along with the metallogenic time of the deposits;8）The Mo deposits in NE China were formed in subduction-related accretionary orogenesis and continental collision orogenesis（including post-collisional tevtonism）,but the Mo-only deposits began to appear in Triassic,i.e.only in continental collision setting（including post-collision）.