寿昌-临浦火山岩带特征及成岩环境

The Rock Zone Characteristics and Diagenetic Environment of Volcanic Rocks in Shouchang linpu,Zhejiang Province

本文阐述了浙江寿昌—临浦火山岩带产出的地质背景、火山活动旋回及火山岩类成分特征，探讨了成岩物质来源及成岩环境。该中生代火山岩带发育于海西—印支造山带内，火山活动受复背斜及其两侧深大断裂控制。火山岩以酸性火山碎屑岩及熔岩为主，其主体火山岩钾长石含量高，富Ｋ２Ｏ，贫Ｎａ２Ｏ，铝过饱和，稀土总量高，ＬＲＥＥ／ＨＲＥＥ比值大，８７Ｓｒ／８６Ｓｒ初始比值较高，普遍大于０．７１０。表明该火山岩带主要为上部陆壳组分熔融的产物。主体火山岩形成于燕山早旋回挤压构造背景，堆积成岩于氧化间还原环境。

This paper describes the occurrence geological background of volcanic rocks zone, volcanic activity cycle and the composition characteristics of volcanic rocks, and discusses the source of diagenetic material and diaginetic environment. The Mesozoic volcanic rock zone is developed in Hercynian-Indo-Chinese epoch orogeny belt. Volcanic activity is controlled by anticlinorium and the deep and big fractures of its two sides The volcanic rocks is mainly composed of acidic volcanic clastic rock and lava. The main volcanics is high in K-feldspar content, rich in K 2O,poor in Na 2O,its aluminum is over saturation.It has high total REE content, big LREE/HREE ratio value and high initial 87 Sr/ 86 Sr ratio value and the value is generally over 0.710.The volcanic rock zone is the product of up crust composition partly melting The main volcanic rocks is formed in squeezed structure background in Yenshan early cycle, accumulated and formed in redox environment.