鄂尔多斯盆地西部中奥陶统克里摩里组沉积特征研究
Study on sedimentary characteristics of Middle Ordovician Keliomori Formation in western Ordos Basin
欧阳征健 1冯娟萍 2姚韦卓 2李文厚 3王治中 1于世宇 1蔺赟婷 1武文源 1于天泽1
作者信息
- 1. 兰州城市学院培黎石油工程学院,甘肃兰州 730070
- 2. 西安科技大学地质与环境学院,陕西西安 710054
- 3. 西北大学地质学系,陕西西安 710069
- 折叠
摘要
鄂尔多斯盆地西部下古生界奥陶系因油气勘探潜力大一直备受关注.其中,中奥陶统克里摩里组发育的碳酸盐岩有望成为下一个勘探目标层,因此,对其沉积特征进行深入剖析可以为西缘奥陶系天然气勘探提供地质依据.通过野外剖面考察、岩心观察和薄片鉴定等手段,研究了克里摩里组的岩石学特征、沉积相类型及其空间展布规律.结果表明,克里摩里组岩性主要为薄层泥晶灰岩、砾屑、砂屑、粉屑灰岩、(含)生物碎屑灰岩及黑色页岩.泥晶结构、粒屑结构发育可见薄层状、纹层状、瘤状、角砾状构造和滑塌及鲍马层序.沉积相类型以台地前缘斜坡和深水斜坡海槽发育为主要特征,表现为沿南北向呈狭窄的条带状展布,在自东向西方向上,紧邻鄂尔多斯本部的开阔海台地发育台地前缘斜坡相带,向西迅速相变为深水斜坡海槽相,海水具有逐渐加深的趋势.
Abstract
The Lower Paleozoic Ordovician system in the western Ordos Basin has attracted much attention be-cause of its great potential for oil and gas exploration,and the carbonate rock developed in the Middle Ordovi-cian Keliomori Formation is expected to be the next exploration target layer,so study on its sedimentary char-acteristics can provide geological basis for the exploration of Ordovician gas in the west margin.By means of outcrops investigation,core observation and thin section identification,the characteristics of petrology,sedi-mentary facies types and spatial distribution of the Keliomori Formation are studied.It is shown that the Kelio-mori Formation is mainly composed of thin layer micrite,calcirudyte,calcarenite,calcisiltite,bioclastic lime-stone and black shale.They have micrite structure,granular structure,and thin layer,lamellar,nodular,brecciform structure,slump and Bauma sequence can be seen.The sedimentary facies platform front slope and deep water slop-trough,which are distributed in a narrow strip along the north-south direction.From east to west,the platform front slope facies develops in the open sea platform close to the Ordos base,and rapidly changes into deep water slop-trough facies westward,and the sea water has a gradual deepening trend.
关键词
鄂尔多斯盆地西部/奥陶系/克里摩里组/沉积特征Key words
western Ordos Basin/Ordovician/Keliomori Formation/sedimentary characteristics引用本文复制引用
出版年
2024
NETL
NSTL
万方数据