Abstract:
A set of complete Cambrian dolostone strata was found in Penglaiba section of Keping area,Tarim Basin.Through the detailed field measurements,lithological description,samples collection and slices observation under microscope, an integrated Cambrian stratigraphic column was compiled and analysis of sedimentary facies of these strata were conducted.One kind of facies was identified in the study area:Carbonate platform facies,which can be divided into three subfacies including open platform,restricted platform and evaporative platform.These subfacies include two microfacies respectively.Open platform includes open tidal flat and particles beach;restricted platform includes restricted tidal flat and lagoon;evaporative platform includes evaporative tidal flat and salt lake.The subfacies and microfacies were analyzed,and three facies models were established: Open platform model,restricted platform model and evaporative platform model.The microfacies of these three kinds of platforms turned to be interactivly deposited showing some rhythms.The vertical evolution of the sedimentary environment of the Cambrian in the study area reflects the relative sea-level changes as rising-falling-rising tendency.
Key words:
microfacies,
subfacies,
dolostone,
Cambrian,
Keping area,
Tarim Basin
摘要: 在塔里木盆地西北缘柯坪地区的蓬莱坝剖面发现一套完整的寒武系白云岩地层,对其进行了系统的野外测量、岩性描述、样品采集和镜下观察,作出了完整的地层岩性沉积相综合柱状图,并对其进行沉积相、亚相和微相的分析。在该剖面中,识别出1种相——碳酸盐岩台地相,并进一步分为3种亚相和6种微相,分别为:开阔台地亚相(开阔潮坪、颗粒滩)、局限台地亚相(局限潮坪、潟湖)、蒸发台地亚相(蒸发潮坪、膏盐湖)。提出了适合该地区的3种碳酸盐岩台地模式:开阔台地亚相模式、局限台地亚相模式和蒸发台地亚相模式。这3种台地中发育的2种微相都交互沉积,呈现一定的韵律。研究区寒武系各组的沉积相在纵向上的演化反映了海平面先升后降再升的趋势。
关键词:
微相,
亚相,
白云岩,
寒武系,
柯坪地区,
塔里木盆地
CLC Number:
Liu Ling, Zhu Jingquan, You Xuelian, He Kai. Sedimentary microfacies of the Middle-Upper Cambrian dolostone in Keping area,Tarim Basin[J]. JOURNAL OF PALAEOGEOGRAPHY, 2012, 14(1): 33-43.
刘玲 朱井泉 由雪莲 何凯. 塔里木盆地柯坪地区中上寒武统白云岩沉积微相*[J]. 古地理学报, 2012, 14(1): 33-43.