鄂尔多斯盆地西北缘克里摩里组沉积微相特征  

SEDIMENTARY MICROFACIES CHARACTERISTICS OF KELIMOLI FORMATION,NORTHWESTERN ORDOS BASIN

作　　者：潘博[1,2] 张成弓[1,2] 陈安清[1,2] 杨帅[1,2] 岳强 刘懿锋[4] 

机构地区：[1]成都理工大学沉积地质研究院 [2]"油气藏地质与开发工程"国家重点实室.成都理工大学 [3]北京地质矿产研究院 [4]中国人民解放军95661部队后勤部

出　　处：《天然气勘探与开发》2016年第3期6-10,1-2,共5页Natural Gas Exploration and Development

基　　金：国家重大专项(2008ZX05002)"大型油气田及煤层气开发"地调项目资助

摘　　要：目前针对鄂尔多斯盆地西北缘下奥陶统的沉积微相类型及组合特征方面的研究尚薄弱。为此以野外露头剖面观察和钻井资料为基础,结合显微薄片鉴定,对鄂尔多斯盆地西北缘下奥陶统克里摩里组的沉积微相进行了精细分析。结果表明:1研究区主要发育局限台地相、开阔台地相、台地边缘相、深水陆棚-盆地相及相应的沉积微相组合,编制的沉积微相图揭示了不同时期的沉积微相展布规律;2克里摩里组沉积期,由于受加里东运动的强烈影响,南北秦岭和兴蒙洋壳加速俯冲挤压,造成了鄂尔多斯地块快速抬升,研究区东部成为剥蚀区,西部沉积区的相带呈南北向带状展布,相带由东往西依次为以云岩沉积为主的局限台地环境、以石灰岩沉积为主的开阔台地环境、以礁滩组合构成的台地边缘环境及深水陆棚-盆地环境;3研究区克里摩里组时期礁滩相带的分布从克1段至克3段受水体能量增强及生物丰度增加的影响其规模逐渐扩大,且由南向北逐渐扩展。结论认为,研究区克3段的礁滩相带可能是该区下一阶段的有利油气勘探目标。Previous research on the type and association of sedimentary microfacies in the Lower Ordovician of northwestern Ordos Basin remained weak. So, in this study, based on field outcrop, drilling data, and thin-section observation, we implemented a fine analysis on the sedimentary microfacies for the Lower Ordovician Kelimoli Formation. Results show that in this study area, there are mainly developed restricted platform facies, open platform facie, platform marginal facies, and deepwater shelf to basinal facies, along with their relevant microfacies compound. In addition, the sedimentary microfacies figure demonstrates their distribution during different stages. And during the deposition of this formation, affected strongly by the Caledonian Movement,both north and south Qinling Mountains along with Xingmeng Oceanic Crust subducted and compressed, further led to a rapid uplift for Ordos block, which the eastern study area became a denudation one whereas a depositional one for the west. In the western depositional area, the facies belts appeared a NS-trending distribution with band in shape, and including from east to west in order, the restricted platform dominated by dolomite, the open platform with limestone as the soul,the platform margin of shoal-bioreef assemblage, and the deepwater shelf to basin. Influenced by strong waterbody and plenty of organisms from the Kelimoli 1 to 3 members, shoal-bioreef facies belt became larger and larger and extended northward. It's deemed the shoal-bioreef of Kelimoli3 Member may be the next favorable target.

关 键 词：鄂尔多斯盆地西北缘 下奥陶统 克里摩里组 沉积微相 

分 类 号：P618.13[天文地球—矿床学]