中国区域成矿研究的若干问题及其与陆-陆碰撞的关系

在中国区域成矿作用研究中 ,遇到诸多重大问题 ,如 :(1)中国东部属于环太平洋地区之一 ,但为什么热液矿床大规模成矿时代不同于环太平洋的新生代 ,而爆发于中生代的燕山期 ?(2 )中国陆区经历了 >3.0Ga的演化 ,为什么大规模成矿作用在东部地区爆发于燕山期 ,西南特提斯成矿域爆发于新生代 ,而西北中亚成矿域爆发于海西期晚期 ?(3)国外不少著名成矿省位于太古宙克拉通内部 ,为什么中国的有色贵金属等热液矿床却集中分布于显生宙造山带内部或其边缘 ?(4)按照绿岩带金矿成矿理论 ,绿岩带型金矿化伴随或尾随于克拉通化 ,形成在太古宙 ,为什么中国绿岩带型金矿却形成在克拉通化后的 2 0多亿年以后的中生代 ?(5 )世界范围内 ,海相油田的重要性远大于陆相 ,为什么中国情况恰相反 ,陆相油田远比海相油藏重要 ?……。笔者认为这些问题彼此相关 ,代表了中国区域成矿的特色 ,其根本原因在于中国陆区不同构造单元经历了晚古生代以来的强烈碰撞事件 ,因此加强研究碰撞造山体制的成岩、成矿、成藏和流体作用是解决这些问题的关键途径。

SEVERAL IMPORTANT PROBLEMS IN STUDY OF REGIONAL METALLOGENESIS IN CHINA:THEIR RELATIONSHIP TO CONTINENTAL COLLISION

Several difficult problems have been encountered in the study of the regional metallogenic regularity in China. They are as follows: (1) As one of the Circum-Pacific areas, Chinese large scale hydrothermal metallogenesis occurred in the Yanshanian of Mesozoic, contrasting with that of the other Circum-Pacific areas where Large scale mineralization occurred in Cenozoic; (2) The mainland China geologically evolved > 3.0 Ga, but its large scale mineralizations exploded at Yanshanian in east area, Cenozoic in Tethysian domain of Southwestern China, and late Hercynian in Central Asia domain of Northwestern China respectively; (3) Many large metallogenic provinces distribute in inner craton in the world, while the metallic hydrothermal deposits distribute in Phanerozoic orogens or their sides; (4) According to the metallogenic model for greenstone-hosted gold deposits, gold mineralization occurred simultaneously with or tightly followed cratonization of greenstone belts, i.e. in Archean generally; whereas the gold deposits hosted in greenstone belts in China formed in Mesozoic, 2.0 Ga later than the cratonization of the greenstone belts; and (5) In the world, the marine oil systems are far more significant than the nonmarine oil systems worldwidely, on the contrary, in China, nonmarine oil systems take the advantage of oil reserves. The author thinks that these problems are not independent, they reflect the distinctive feature of the regional metallogeneses in China, which had resulted from intensely collisions between various continents or blocks since late Paleozoic. Hence the study of petrogenesis, metallogenesis, hydrocarbon accumulation, and fluidization during collisional orogenesis may enable us to deeply understand these problems.