摘要
重庆城口震旦系下统陡山沱组共分两段,主要发育浅海陆棚沉积相,包括过渡相和滨外陆棚两个微相。对区内钻井剖面及露头剖面进行分析,识别出岩性岩相转换面、陡山沱组与观音崖组之间界面两种层序界面类型,将陡山沱组划分为4个Ⅱ型三级层序。其中层序1为陡山沱组第一段底部,层序2为陡山沱组第一段中部,层序3为陡山沱组第一段上部和第二段底部,层序4为自陡山沱组第二段下部至灯影组第一段底部中厚层状白云岩。基于浅海陆棚的背景,研究区陡山沱组第四次海平面广泛上升至最大海泛面滞后时段内,在深水、还原、偏碱性的浅海滨外陆棚环境下锰矿才开始聚集,且在高燕、修齐等锰矿区成为重要的开采矿床。
The lower Sinian Doushantuo Formation in Chengkou, Chongqing can be partitioned into two members, mainly developed neritic shelf sedimentary facies including transitional and offshore shelf two microfacies. After analysis of borehole section and outcrop section, two sequence boundary types of lithology, lithofacies transitional surface and interface between Doushantuo Formation and Guanyinya Formation, partitioned the Doushantuo Formation into 4 type II third-order sequences, in which, the sequence 1 is in the bottom part of first member, sequence 2 in the middle part of first member, sequence 3 in the upper part of first member, and bottom part of second member, sequence 4 from Doushantuo Formation second member lower part to the Dengying Formation first member bottom part medium thick stratified dolomite. Based on neritic shelf setting, study area Doushantuo Formation from the fourth sea level wide rise to maximum marine-flooding surface lag period, under deep water, reduction, alkalescent, neritic offshore shelf environment, and then the manganese ore accumulation just started, formed important mineable manganese ores in the Gaoyan, Xiuqi etc. areas.
作者
高彩霞
黄朝阳
冉瑞清
张自贤
李北平
Gao Caixia;Huang Chaoyang;Ran Ruiqing;Zhang Zixian;Li Beiping(School of Geosciences andSurveying Engineering,CUMTB,Beijing 100083;No.205 Geological Team,Chongqing Bureau of Geology and Mineral Resources Exploration and Exploitation,Chongqing 401147;Sate Key Laboratory of Coal Resources and Safe Mining)
出处
《中国煤炭地质》
2019年第2期15-20,50,共7页
Coal Geology of China
基金
重庆市国土资源与房屋管理局科技项目(KJ-2015019)
重庆市教委项目(2015ZX011)
重庆市教委项目(2018ZX028)
重庆工程职业技术学院校级课题(KJB14)联合资助
关键词
陡山沱组
层序地层
锰矿聚集
重庆城口
Doushantuo Formation
sequence stratigraphy
manganese ore accumulation
Chengkou, Chongqing
