浙江天姆尖盆地中生代岩浆岩组合特征及与铀矿化的关系

Study on Characteristics of Magmatic Rock Series of Mesozoic era in the Tianmujian Basin, Zhejiang Province

天姆尖盆地存在三套不同特征的岩浆岩组合 ,第一套岩石组合由黄尖组的英安质凝灰岩、英安质角砾凝灰熔岩、安山质角砾熔岩 -辉长闪长玢岩组成 ,该套岩石组合受基底断裂及火山机构控制 ,形成于挤压环境 ,与铀矿化关系不密切。第二套岩石组合由寿昌组Ⅰ、Ⅱ类流纹岩 -流纹斑岩 -二长岩、石英正长岩组成 ,本套岩石组合受北东向深构造控制 ,形成于挤压转向拉张的过渡环境 ,与铀矿化关系非常密切 ,流纹岩是该组合中最重要的控矿岩石。第三套岩石由橄榄岩、橄榄辉石岩、辉绿岩组成 ,受基底深大断裂控制 ,形成于拉张环境 ,辉绿岩与铀矿化关系密切。

There are three series of magmatic rock with different characteristics in Tianmujian basin. The first series is formed by Fangjian Group's dacitic tuff, dacitic breccia tuff lava, andesitic breccia lava-gabbro dioritic porphyrite, controlled by basement fault and volcanic structure. It is formed in compressional geologic setting. The second series compose of Shouchang Group's two kind rhyolite, named Ⅰand Ⅱ-rhyolite, granophyre-monzonite, quartz syenite, controlled by east-north deep fault. It is formed in transitional environment from compression to extension. The third series composed of peridotite, ankaramite and diabase, controlled by basement deep megafault. It is formed in the extensional geologic setting.