中国东南部晚中生代花岗质火山-侵入杂岩特征与成因  

Characteristics and Petrogenesis of Late Mesozoic Granitic Volcanic-Intrusive Complexes in Southeastern China

作　　者：王德滋[1] 周金城[1] 邱检生[1] 范洪海 

机构地区：[1]南京大学地球科学系,江苏南京210093

出　　处：《高校地质学报》2000年第4期487-498,共12页Geological Journal of China Universities

基　　金：国家自然科学基金重点资助项目!(编号 :496 32 0 80 )

摘　　要：晚中生代期间 ,中国东南部岩浆活动十分强烈。由内陆向沿海 ,花岗岩、火山岩的时代越来越新。花岗岩与酸性、中酸性火山岩在成因上存在密切联系。在时间、空间和成岩物质来源一致的条件下 ,花岗岩可视为流纹岩、英安岩所构成的中心式火山机构的“根” ,形成所谓的花岗质火山 侵入杂岩。中国东南部的花岗质火山 侵入杂岩可以区分为同熔型、陆壳重熔型和A型三类 ,它们具有不同的构造环境、形成机制和物质来源。同熔型火山 侵入杂岩主要分布于沿海 ,陆壳重熔型火山 侵入杂岩一般分布于内陆 ,而A型花岗质火山 侵入杂岩主要受浙闽沿海长乐 南澳断裂带控制。以桐庐和相山两个典型杂岩体为代表剖析了花岗质火山 侵入杂岩体的时、空、源一致性 ,所揭示的规律对于认识整个中国东南部晚中生代花岗质火山During the late Mesozoic, magmatic activities in southeastern China were very intensive. In the products of magmatism, the granites rhyolites are predominant, and the andesitic basaltic rocks are less important. The statistical data on the isochron ages for over 200 granite and volcanics samples show that the early Cretaceous ages make up about 60% of age population; and the late Jurassic, 20%; the late Cretaceous, 10%; the middle Jurassic, 10%. The ages of Mesozoic volcanics and related granites in southeastern China have a tendency of getting younger from the inland toward the coast. In some cases, granites and associated acidic and intermediate volcanic rocks are comagmatic. Under the condition of uniformity in time, space and source materials, the granities can be considered as the “roots” of the central type volcanic apparatuses composed of rhyolites and dacites, forming so called granitic volcanic intrusive complexes. The granitic volcanic intrusive complexes in southeastern China may be divided into three types, i.e., syntexis type, continental crust remelting type and A type. Their petrogenesis is controlled by different tectonic settings, rock forming mechanisms and source materials. The syntexis type is dominantly distributed in the coastal area, whereas the continental crust remelting type is mainly located in the inner land. This spatial pettern is constrained by two factors: the composition of basement rocks and the intensity of crust mantle interactions. Underplating of basaltic magma took place more intensively in the coastal area of Zhejiang and Fujian provinces during the late Mesozoic. Therefore, the crust mantle interaction was also more intensive in the coastal area than in the inner land. In the west of Wuyishan Mts., the continental crust usually possesses higher maturity. The meta igneous materials, such as amphibolites, are rare or absent in the basement rocks of the area. The combining constraints of these two factors led to a regular spatial distribution of above ment

关 键 词：花岗质火山-侵入杂岩 岩石成因 晚中生代 中国 

分 类 号：P588.14[天文地球—岩石学] P534.5[天文地球—地质学]