【摘要】 通过对塔河南盐下地区28口钻井岩心中奥陶统一间房组的详细描述和3 200余块薄片的鉴定,确认其主要的岩石类型有生屑灰岩、生物灰岩、藻球粒灰岩、含核形石灰岩、鲕粒灰岩、内碎屑灰岩、微晶灰岩、海绿石灰岩。在这些碳酸盐岩中,藻类、棘皮类、双壳类以及造礁生物苔藓虫、珊瑚、层孔虫、海绵等生物大量出现,表明一间房组沉积时期总体应为一个水体循环状况良好、盐度正常充氧的浅海沉积环境。在综合分析其岩石学特征、测井资料,结合地震资料,划分出台内滩、滩间、点礁三种沉积相,并讨论了一间房组早、晚期沉积相的空间展布特征,编制了各时期的古地理图,为油气勘探提供了地质指导。更多还原

【Abstract】 The Middle Ordovician Yijianfang Formation mainly consists of carbonates in the south of Tarim River area of Xinjiang.The authors have observed 28 cores and identified 3200 slices.They think the rock types are bioclastic limestone,biolithite,algal pelleted limeston,oncolite limestone,oolitic limestone,intraclastic limestone,micrite,glauconite limestone.Algae,echinoderm,bivalve,and reef-building organisms including bryozoan,coral,stromatoporoids,and sponge are conserved in the carbonate of the Yijianfang Formation.This indicates a normal shallow marine environment with water cycle,normal salinity and sufficient oxygen.Based on the integrative analysis of seismic data,log data and petrologic character,three types of sedimentary facies can be recognized in the Yijianfang Formation.They are platform shoal,intershoal,and patch reef.Based on this,the paleogeographic maps about the early Darriwilian Stage and late Darriwilian Stage are mapped,respectively.At last,the authors describe the depositional facies distribution in space.This is very important for people to engage oil and gas exploration in study area.更多还原