华蓥溪口剖面中二叠统栖霞组沉积相分析

在大量前人研究的基础上,通过野外实测,华蓥溪口剖面中二叠统栖霞组分为两段,总厚度115.11 m。该剖面岩石以石灰岩为主,含少量白云岩和硅岩。石灰岩进一步分为生屑微晶灰岩、泥晶灰岩、微晶生屑灰岩以及泥晶生屑灰岩。结合野外剖面、显微分析和区域沉积背景等资料的综合分析,认为栖霞组一段下部沉积环境为深缓坡的上带,栖霞组一段上部沉积环境为浅缓坡的上带,栖霞组一段顶部为局限台地亚相的泻湖微相,栖霞组二段沉积环境为开阔台地亚相的生屑滩微相和台内洼地微相。

Analysis on Sedimentary Facies in the Qixia Formation, Middle Permian at Huaying Xikou Section

Based on numerous previous researches and a lot of field surveys,the Qixia Formation of Middle Permian at Huaying Xikou section has been divided into two sections,with total thickness of 115.11 m.The rock types of this section are simple,dominated by limestones,with minor dolomites and siliceous rocks.The limestones can be further divided into bioclastic microcrystalline limestone,micritic limestone,microcrystalline bioclastic limestone and micritic bioclastic limestone.Based on the field section, microscopic analysis and a comprehensive analysis on the background of the regional deposition,it is believed that the depositional environment of the lower of the first section of Qixia Formation is upper part of deep ramp,the upper part is upper zone of shallow ramp,the top of the first section is lagoon face on restricted platform,the second section of Qixia formation is considered as open platform,including bioclastic beach microfacies and depression facies in platform.