山东新泰盘车沟剖面寒武系硅质层成因

ORIGIN OF THE SILICEOUS ROCRS OF THE CAMBRIAN ON PANCHEGOU SECTION AT XITAI AREA OF SHANDONG PROVINCE

利用野外地质资料和室内分析资料，从成因类型和形成机理方面对盘车沟寒武系剖面中硅质层进行了研究。结果表明，镘头组下部的硅质层是同生期生物化学作用成因的，形成于潮下低能浅水环境；中、下寒武统与泥质共生的硅质层是成岩期呈分散状的硅质沉积物溶解、聚集、交代成因的。在硅质形成过程中，粘土矿物对ＳｉＯ２胶体质点起着吸附和提供部分氧化硅的作用。张夏组顶部硅质层是经过白云岩化作用之后交代成因的。

By the use of the materials from the fieldwork and laboratory experiment on the origin types and formation mechanism, the siliceous rocks of the Cambrian in the Panchegou section was studied. The siliceous rocks of the lower Mantou formation were resulted from the biochemical action during the sedimentary period and formed in the environment of low-tide shallow sea. The siliceous rocks related with mud-rock were origined by the scattered siliceous deposits under the actions of dissolving. collecting and replacement in diagentic stage. The clay minerals played an important part for adsorbing and providing SiO2. The siliceous rocks of the upper Zhangxia formation were origined from the silicification after dolomitization.