福安地区碎斑熔岩的基本特征及成因  

Basic Characteristics and Genesis of Porphyroclastic Lava in the Fu'an Area

作　　者：林国辉[1] 

机构地区：[1]福建省区域地质调查队,三明365001

出　　处：《福建地质》2003年第4期171-180,共10页Geology of Fujian

基　　金：<纯池;上白石;周宁县;福安市幅 1: 5万区域地质调查>项目 (国土资源大调查项目;项目编号2 0 0 0 130 0 0 12 3)的部分成果

摘　　要：福安地区碎斑熔岩的形成受北东向火山基底断裂控制 ,具有明显的分带现象 ,由中心到边缘可划分出酸性粒状碎斑熔岩、中酸性粒状碎斑熔岩、中酸性霏细状碎斑熔岩、酸性霏细状碎斑熔岩、酸性隐晶状碎斑熔岩等岩石类型 ,是晚侏罗世火山活动衰亡时期岩浆以侵出 -溢流形式活动的产物。碎斑熔岩与同期潜火山岩、流纹质晶屑熔结凝灰岩 (熔离型 )是同源岩浆分异及演化的结果 。The porphyroclastic lava in the Fu'an area is controlled by the northeast-trend volcanic basement faults and has obvious a zonation. Form center to margin, it can be divided into five lithological types: acid granular porphyroclastic lava, medium-acidic granular porphyroclastic lava, medium-acidic felsitic porphyroclastic lava, acid felsitic porphyroclastic lava and acid aphanitic porphyroclastic lava, which are the product of magmatic intrusion and overflow in the failed stages of Late Jurassic volcanic activity. The porphyroclastic lava, synchronous subvolcanics and liparite crystal ignimbrite are the product of comagmatic differentiation and evolution. They are composed of a paragenesis geological body of three lithofacies in space.

关 键 词：碎斑熔岩 碎斑结构 侵出-溢流相 福安地区 

分 类 号：P588.1[天文地球—岩石学]