德化石牛山晚白垩世火山岩岩浆来源及其演化  

THE GENESIS AND EVOLUTION OF LATE CRETACEOUS VOLCANIC MAGMA IN SHINIUSHAN, DEHUA COUNTY

作　　者：冯宗帜 李进堂 黄水兴 许美辉 王国金[1] 何文兴[1] 

机构地区：[1]福建省区域地质调查队

出　　处：《福建地质》1989年第4期275-285,共11页Geology of Fujian

摘　　要：石牛山位于福建的东部,其平面呈椭园形,面积约600平方公里,四周为环状、放射状断裂与充填其中的岩墙和岩脉。中部堆积的火山喷发-沉积岩系,厚度达1200米以上,它是福建东部一个具代表性的晚白垩世破火山口。火山岩为中酸-酸偏碱性,属于欧文(1964)分类的高钾钙碱系列。从锶的初始比值,可知其原始岩浆属于幔壳混源型,原始成份为英安质岩浆。火山岩戈蒂里-里特曼指数图解,说明本区火山岩是活动大陆边缘环境中的造山晚期岩浆活动的产物。从岩石稀土分布模式、铕亏损明显等说明岩浆经历了与晶洞花岗岩相似的分异和演化,具有由中酸性向酸偏碱性演化的趋势。Shiniushan is situated in the east Fujian. Its area is about 600 sqare kilometers with an elliptical figure in plane, The ring-like and radiate faults and veins filled in the faults appear in the area around it, In the middle a volcanic-sedimentary strata with a thickness of more than 1 200 meters can be found, It is a typical caldera of Late Cretaceous in east Fujian. The volcanic rocks are medioacidity to acidulous alkalinity. They are classified into the high potassium calc-alkaline series in Owen Category. According to its Sr initial ratio the original magma may be the mixed with mantle and crustal materials. The initial composition of this magma is dacitic. The Gottinni-Rittman diagram shows that the volcanic rocks in this area is the product of late orogenic magmatic along active continental margin. The rare aerth partition curves show strong Eu negative anomaly. There for it is considered that this magma has the same process of differentiation and evolution as the Miarolitic Granite and has the tendency developing from medio-acidity to acidulous alkal linity.

关 键 词：晚白垩世 火山岩 岩浆 

分 类 号：P588.14[天文地球—岩石学]