吉黑东部燕山早期斑岩型钼矿床、燕山晚期斑岩型铜矿床成矿机制探讨  

Discussion of the metallogenic mechanism of the early Yanshan porphyry Mo deposits and the late Yanshan porphyry Cu deposits in eastern Jilin and Heilongjiang

作　　者：李碧乐[1] 史雨凡 于润涛 孙永刚[1] Li Bile;Shi Yufan;Yu Runtao;Sun Yonggang(College of Earth Sciences,Jilin University)

机构地区：[1]吉林大学地球科学学院,130061

出　　处：《黄金》2020年第9期28-34,共7页Gold

基　　金：吉林省自然科学基金项目(20180101089JC)。

摘　　要：吉黑东部燕山早期(早—中侏罗世)广泛发育斑岩型钼矿床,同期还发育矽卡岩型金矿床和造山型金矿床。3类矿床受统一挤压构造背景控制,形成于太平洋板块向欧亚大陆俯冲过程中,强烈挤压过程中由挤压向伸展的转换时期。与斑岩型钼矿床成矿有关的斑岩为高钾钙碱性、准铝质—略过铝质、分异指数高的壳源花岗岩,钼矿质主要来源于硅铝质地壳。燕山晚期(早白垩世晚期)是浅成低温热液型金(铜)矿床形成的高峰期,也发育斑岩型铜矿床如常发沟铜矿床,二者构成不同地壳深度层次的成矿系列。矿床形成于中国东部与太平洋板块俯冲有关的岩石圈强烈减薄时期,为弧后伸展的构造背景。斑岩型铜矿床与成矿有关的侵入岩为分异指数偏低的中酸性—偏碱性浅成侵入岩,岩浆源区和铜矿质主要来源于新生地壳,次为幔源或混合源。早—中侏罗世浅成酸性侵入体、早白垩世晚期中酸性—偏碱性浅成侵入体分别是斑岩型钼矿床和斑岩型铜矿床找矿的目标地质体。Porphyry Mo deposits widely developed in the early Yanshan(Early-Middle Jurassic)in the eastern Jilin and Heilongjiang,and skarn-type gold deposits and orogenic-type gold deposits also developed during the same period.The three types of deposits were controlled by a unified compression structure background,and were formed during the subduction of the Pacific plate to Eurasia continent and the transition period from compression to extension in the process of strong compression.The porphyry related to the porphyry Mo deposit mineralization is crust-derived granite with high potassium calc-alkaline,metaluminous-weakly peraluminous and high differentiation index.The Mo minerals mainly come from ancient sialic crustal materials.The late Yanshan(late Early Cretaceous)was the peak period for the formation of epithermal Au(Cu)deposits,and porphyry Cu deposits also developed,e.g.Changfagou Cu Deposit,and the two constituted different crustal depth levels of metallogenic series.The deposits were formed during the period of intense thinning of the lithosphere related to the subduction of the Pacific plate in eastern China and the tectonic setting of back-arc extension.The intrusive rocks related to porphyry Cu deposit mineralization are interme-diate-acidic-alkaline hypabyssal intrusive rocks with relatively low differentiation index.The magma and the Cu mine-rals are mainly derived from the juvenile crust,and secondly from the mantle or crust-mantle mixed sources.Early-Middle Jurassic hypabyssal acidic intrusive bodies and late Early Cretaceous medium-acidic-alkaline hypabyssal intrusive bodies are target geological bodies for prospecting porphyry Mo deposits and porphyry Cu deposits respectively.

关 键 词：燕山早期 斑岩型钼矿床 燕山晚期 斑岩型铜矿床 成矿机制 吉黑东部 

分 类 号：TD11[矿业工程—矿山地质测量] P618.41[天文地球—矿床学]