蓟县地区雾迷山组硅质岩成因研究  

The Origin of Siliceous Rock in Wumishan Formation,Jixian,Tianjin

作　　者：任国选[1] 孟祥化[1] 葛铭[1] 王德海[1] 郭峰[1] 

机构地区：[1]中国地质大学沉积盆地研究所,北京100083

出　　处：《沉积学报》2008年第1期70-76,共7页Acta Sedimentologica Sinica

基　　金：国际地质对比计划IGCP447项目(编号:SC/GEO/546/447);科技部国家重点基础研究项目(001CB711002);国家自然科学基金(批准号:40172043;40572073);中国地质调查局项目(编号:200313000055)

摘　　要：中晚元古代华北地台处于燕辽拗拉谷的张裂期,有利于形成风暴流。蓟县雾迷山组广泛发育风暴沉积,在硅质条带白云岩中发育硅质砾屑具奇特的菊花状构造,这种构造形成于成岩作用后期,在尚未完全固结成坚硬的岩石时期,遭遇风暴破坏,将原有水平层理打碎,继而被风暴流搅起,风暴流的涡动使得岩石碎片直立,或者呈发散状,后经成岩作用保留了这种构造形态,与上下岩层形成典型的风暴沉积序列。通过野外与镜下观察并结有机地球化学分析得出,蓟县地区雾迷山组硅质条带白云岩发育典型的风暴沉积序列和挤压滑塌序列,风暴硅质岩具丘状形态,内部菊花状构造为近源风暴产物,其中硅质岩来源于海底热水活动。沉积环境推测为碳酸盐台地前缘斜坡。Sino-Keorea plate was in tensile period of Yan-liao aulacogen in the Mesoproterzoic, which likely to trigger big storm. It was well developed the stromatolite and coagulum stone bioherm, and which mainly consists of dolomite interbeded with siliceous rock. Research shows that there developed storm siliceous rock in this area. Storm siliceous rock with surface of scour, siliceous gravel arranged as daisy, which was formed in storm surge, and destroyed in the late period of the diagenetic stage before they got consolidated or compacted, which resulted the siliceous fragments straight on the under layers, and formed typical storm deposit. Stromatolithic dolomite interbeded with siliceous strip was normal weather deposit. The paper concluded through the micro photo and field work that the typical storm depositional series of siliceous rock in Wumishan formation, Jixian. The scour-like structure and buninoid structure were developed in the storm siliceous rock, which were the fast and proximal sedimentary deposit. And the origin of the siliceous rock mostly could be seemed as the thermal water activities offering the SiO2. Deposit environment could be the slope of the carbonate platform.

关 键 词：硅质岩 风暴序列 雾迷山组 

分 类 号：P512.2[天文地球—地质学]