摘要
本文主要论述中国沿海及其邻侧火山作用的构造背景、火山岩的岩石学和地球化学特征,以及其有关的成矿作用。认为该区自震旦纪以来的火山作用,尤以中新生代大陆边缘活动带阶段最强,与板块俯冲、裂谷作用有关,并伴随丰富多彩的成矿作用。指出,由于太平洋-库拉板块向欧亚板块俯冲,所形成的晚侏罗世巨厚的中酸性火山岩建造是西环太平洋火山岩带外带的主体组成部分,由大陆板块边缘至内部,离俯冲带愈远,幔源组分逐渐增加;从白垩纪至新生代,火山作用主要与裂谷作用有关。由大陆至海洋,裂谷拉张规模愈来愈大,时代愈来愈新,呈现出由陆内裂谷→陆间裂谷→大洋裂谷、由双峰式火山岩→玄武岩的演化规律。还指出,形成于不同构造背景的火山作用具有不同的成矿专属性。与晚侏罗世俯冲带型火山岩有关的叶腊石(含寿山石)、瓷土和优质高岭土等矿产;与早白垩世陆内裂谷型火山岩有关的明矾石、珍珠岩、沸石和膨润土等矿产;与新生代陆间裂谷型玄武岩有关的蓝宝石、红宝石、红锆石和风化壳型三水铝土矿,以及产于火山口湖的硅藻土、膨润土和泥炭等矿产。
This paper has mainly dealt, with the structural setting of volcanism, the petrologic and geochemical characteristics of volcanic rocks and its related mineralization along the coast of southeastern China and its vicinity. It has believed that the volcanism in this area, since the Sinian Period, in particular the stage of the Mesozoic and Cenozoic continental marginal mobile beit has been strongest which accompanied by the rich and varied mineralization, this is associated with the plate underthrusting and rifting. It has pointed out that the Late Jurassic intermediate-acid volcanic formation with huge thickness which was formed by the subduction of the Pacific-Kula plate under the Eurasian plate is the main component part of the outer belt of the West Circum-Pacific volcanic rock belt, the mantle-derived component is getting more and more from the margin to the interior of the continental plate; From the Cretaceous Period to the Cenozoic Period, the volcanism was mainly related to the rifting; From the continent to the ocean, the scale of rift extension is getting larger and larger, and its age younger and younger, an evolutional regularity of from intercontinental rift to intercontinental rift to oceanic rift and from two-humped-type volcanic rock to basalt is displaid. It has also pointed out that the volcanisms formed in the structural settings have their own metallogenic specialization. For example, the pyrophyllite (contains agalmatolite), china clay and high-quality kaolinton etc. mineral resources are related to the Late Jurassic subduction zone-type volcanic rocks; the alunite, pearlite, zeolite bentonite etc. mineral resources to the Early Cretaceous intercontinental rift-type volcanic rocks the sapphrire, ruby, red zircon, gibbsite in weathering crust, and diatomite, bentonite, peat in crater lakes, etc. mineral resources to the Cenozoic intercontinental rift-type basalt.
