略论海陆成矿问题

Brief Discussion of the Continental and Oceanic Metallogeny

地壳通过不均一性分异形成大陆型地壳和大洋型地壳,陆核及地块的形成、大陆裂解与增生、洋壳的新生与消减、陆-陆碰撞拼接形成具有不同构造特征的海陆构造区。中国海陆构造演化经历了太古宙陆核形成、元古宙陆块形成、震旦纪至三叠纪联合大陆形成、中新生代联合大陆解体4个阶段,形成北方(准噶尔-大兴安岭)、北部(塔里木-华北)、南部(扬子-华南)、南方(冈底斯-喜马拉雅),东部(滨西太平洋)5个大陆及陆缘构造区。太古宙花岗绿岩带、元古宙裂谷(裂陷)带、显生宙大陆边缘是最重要的海陆成矿环境。海陆成矿有利因素的耦合对成矿至关重要,而最佳耦合的机制及其发生在海陆构造区的时空位置是圈定有利成矿靶区、引导找矿突破的关键科学问题。

Inhomogeneous differentiation split the Earth’s crust into continental and oceanic crusts.The various structural features of the continental and oceanic tectonic belts were formed through the continental nucleus,platform,continent splitting,continental accretion,oceanic crust forming,and subduction or continent-continent collision.China’s continental and oceanic crust structural evolution has experienced four stages:nucleus forming in Archean,platform forming in Proterozoic,Pangaea forming from Sinian to Triassic,and Pangaea splitting in Meso-Cenozoic eons.There are five marginal tectonic belts:Dzungaria–Great Khingan,Tarim–North China,Yangtze–South China,Gangdise–Himalaya,and West margine Pacific.The Archean granitoid-greenstone belts,Proterozoic rift zone,and Phanerozoic continental margin are important environments for continental and oceanic metallogeny.It is very important for metallogeny that advantaged metallogenetic multi-factors are coupled.Their coupling mechanism and space-time distribution in continental-oceanic margins are key to outlining advantaged metallogenetic areas.