中生代复杂构造体系的成矿过程与成矿作用——以华北大陆北缘西拉木伦钼铜多金属成矿带为例  

Ore-forming processes and mineralization of complex tectonic system during the Mesozoic:A case from Xilamulun Cu-Mo metallogenic belt

作　　者：张连昌[1] 吴华英[1] 相鹏[1] 张晓静[1] 陈志广[1] 万博[1] 

机构地区：[1]中国科学院地质与地球物理研究所中国科学院矿产资源研究重点实验室,北京100029

出　　处：《岩石学报》2010年第5期1351-1362,共12页Acta Petrologica Sinica

基　　金：国家重点基础研究发展规划项目(2006CB403506)资助

摘　　要：西拉木伦钼铜多金属成矿带处于华北克拉通与中亚造山带的过渡区,是古生代古亚洲构造域与中生代西太平洋构造域的交汇部位。在中生代受多种构造体系的制约,如中亚造山带造山后期局部伸展、蒙古-鄂霍茨克俯冲-碰撞造山作用、古太平洋板块的向西俯冲和中国东部岩石圈减薄事件的影响等。西拉木伦成矿带成矿斑岩锆石U-Pb年龄和辉钼矿Re-Os同位素年龄资料显示,钼铜矿成岩成矿主要集中在260～220Ma、180～150Ma和140～120Ma三个时期。结合华北克拉通北缘构造演化历史,推测这三期成矿作用主要与造山后局部伸展、构造体系转折和陆内伸展(岩石圈减薄)过程有关,并相应建立了"车户沟式"、"鸡冠山式"和"敖伦花式"三类斑岩钼铜矿床成矿模式。进一步研究表明,岩石的酸碱性、岩浆来源、岩浆的氧逸度、岩浆演化方式、构造背景等因素,制约了成矿作用的专属性。The Xilamulun metallogenic belt,located between Central Asian Orogenic Belt and North China Craton,is situated at the junction between the Paleo-Asian Ocean and the west Circum-Pacific tectonic regime.The ore belt was controlled by some tectonic systems,such as post-collisional extension of the Central Asian Orogenic Belt,Mongolia-Okhosk orogen,west Circum-Pacific tectonic and lithosphere large-scale thinning.Molybdenite Re-Os and zircon U-Pb dating of the Xilamulun ore belt show three periods of mineralizations which occurred at 260 ～ 220Ma,180 ～ 150Ma and 140 ～ 120Ma,respectively.Combined with the regional geology and geochemical study,we suggest that the mineralizations in the belt were formed during multiple geodynamic settings.The mineralization in 260 ～ 220Ma is probably related to a post-collisional extension stage with the generation of the porphyry molybdenum-copper deposits;The stage of 180 ～ 150Ma is related to a tectonic stress transformation from NS to EW;The large-scale mineralization occurred at 140 ～ 120Ma is related to the lithosphere thinning due to the upwelling of asthenosphere under the intra-continent extension.Based on geology and geochemistry of Mo-Cu deposits,authors suggest three ore-forming modes:i.e.'Chehugou','Jiguanshan'and 'Aolunhua'-types.Study data show that ore-forming specialization are restricted by acid-alkali degree of host rock,magma source,oxygen fugacity of rock,evolvement fashion of magma and tectonic setting.

关 键 词：斑岩矿床 成矿专属性 中生代 西拉木伦成矿带 华北克拉通北缘 

分 类 号：P611[天文地球—矿床学]