洛南地区中元古界高山河群二道河组叠层石特征及沉积环境分析  

作　　者：李鹏坤 

机构地区：[1]长安大学,西安710064

出　　处：《科技创新与应用》2024年第18期100-103,共4页Technology Innovation and Application

摘　　要：叠层石记录早期环境、蓝细菌、微生物群落的生命活动,其生长形态受到沉积环境的影响,对古环境恢复具有重要意义。该文选取二道河组叠层石发育剖面为研究对象,对叠层石开展野外宏观形态和室内微观特征分析,据此反演沉积环境演化过程和建立沉积模式。结果显示,二道河组宏观特征可分为水平纹层状、波纹状、丘状,显微表现出明暗纹层,局部含少量鲕粒、球粒、碎屑物质等。可见,洛南地区二道河组岩性主要为一套碎屑岩向碳酸盐岩过渡的岩石类型;二道河组沉积时期洛南地区存在水体较浅的槽状负地形;叠层石可反映二道河组形成于潮坪环境,经历从潮上带—潮间带—潮上带的旋回序列。Stromatolites record the life activities of early environment,cyanobacteria and microbial communities,and their growth morphology is affected by sedimentary environment,which is of great significance to the restoration of paleoenvironment.In this paper,the development profile of stromatolites in Erdaohe formation is selected as the research object,and the macroscopic morphology and indoor microscopic characteristics of stromatolites are analyzed,based on which the evolution process of sedimentary environment is inversed and the sedimentary model is established.The results show that the macroscopic characteristics of Erdaohe formation can be divided into horizontal laminated,corrugated and mound-shaped,microscopically showing light-dark laminated layers and locally containing a small amount of oolitic,spherical and clastic materials.It can be seen that the lithology of Erdaohe formation in Luonan area is mainly a set of rock types from clastic rocks to carbonate rocks;during the sedimentary period of Erdaohe formation,there is a shallow trough-like negative topography in Luonan area;stromatolites reflect the formation of Erdaohe formation in tidal flat environment.It has experienced a cycle sequence from supratidal zone to intertidal zone to supratidal zone.

关 键 词：叠层石 中元古界 二道河组 洛南地区 沉积环境 

分 类 号：P534[天文地球—古生物学与地层学]