沉积与特提斯地质2024，Vol.44Issue(2)：311-325,15.DOI:10.19826/j.cnki.1009-3850.2023.04008
川北旺苍地区奥陶系沉积特征与风暴沉积的发现
Characteristics of Ordovician sedimentation and the discovery of storm deposition in the Wangcang area,northern Sichuan
摘要
Abstract
To clarify the sedimentary pattern and environment of the Ordovician strata in the northern margin of the Upper Yangtze Block,the Dalianghui section was selected as the research profile.Combining the previous studies of the sedimentary facies of the Ordovician strata with detailed profile surveys and microscopic observations in the Wangcang area of the north Sichuan Basin,we conducted a fine division of these sedimentary facies of the Ordovician strata.Results show that the Dalianghui section can be divided into four formations,which are the Zhaojiaba,Xiliangsi,Baota,and Wufeng formations.The lithofacies of the Zhaojiaba and Xiliangsi formations feature tidal flat subfacies of coastal facies,while the Baota Formation is dominated by carbonate platform subfacies of neritic facies.The lithofacies of the Wufeng Formation feature shelf subfacies of neritic facies,which can be further divided into several suborder facies.In this study,storm sedimentary structures were first identified,which mainly consist of scouring-fill structures,storm-generated gravelstones,rip-up clasts,parallel bedding,graded bedding and hummocky cross-bedding.Four types of tempestite sequences were also identified.Therefore,it is suggested that the northern margin of the Upper Yangtze Block was located in the low-latitude hurricane zone of the coastal environment in the Early to Middle Ordovician,and changed into a shallow marine environment in the Late Ordovician.关键词
四川盆地/奥陶系/沉积特征/沉积相/风暴沉积Key words
Sichuan Basin/Ordovician/sedimentary features/sedimentary facies/storm deposits分类
天文与地球科学引用本文复制引用
王牧源,牟传龙,王秀平,侯乾,王启宇..川北旺苍地区奥陶系沉积特征与风暴沉积的发现[J].沉积与特提斯地质,2024,44(2):311-325,15.基金项目
川北地区震旦—下古生界标准剖面建立及沉积格局研究(XNS勘研院JS2021-076) （XNS勘研院JS2021-076）
