摘要
沙县大佑山火山构造是一较典型的火山喷发盆地，面积约150km2。盆地内的火山地层属石帽山群，岩石组合具双峰式火山岩特点。上部流纹岩全岩Rb－Sr等时线年龄为99±3Ma，其形成时代为早白垩世。火山岩相发育较齐全，以爆发相占绝对优势，其空间分布具有一定的规律性。火山构造以西部的大佑山破火山机构较为特征，重点阐述该破火山的地貌特征、火山断裂特点、火山岩相展布及其与火山口的关系，恢复火山喷发盆地形成的历史。
The Dayoushan volcanic-tectonics from Shaxian County, Fujian Province belongs to atypic volcanic eruption base with the area of 150 km2. The volcanic strata in the Base are theShimaoshan Group and the rock association has characteristic of the bimodal volcanic rock.The Rb-Sr age of the rhyolite in the upper part of the Base is 99±3 Ma,which belongs to thelower Cretaceous period. In the Base, there are well-developed volcanic rock faces, especiallyexplosive factes with a regular distribution in space. This paper focuses on the discussion ofthe volcanic geomorphic feature and volcanic fractures of the caldera, the distribution ofvolcanic factes and its relations with the caldera and forming history of the volcanic eruptionbase.
出处
《福建地质》
1998年第3期147-152,共6页
Geology of Fujian
关键词
火山喷发盆地
火山活动
早白垩世
沙县
volcanic eruption base
volcanic activity
Lower Cretaceous
Shaxian County
