古地理学报2025，Vol.27Issue(5)：1173-1188,16.DOI:10.7605/gdlxb.2025.049
滇中地区寒武系筇竹寺组阻塞盆地深水等深流引发内波、内潮汐沉积
Internal-wave and internal-tide deposits in the Cambrian Qiongzhusi Formation induced by deep-water contour currents in ponded basin,central Yunnan Province,China
摘要
Abstract
The sedimentary environment and facies of the Cambrian Terreneuvian-Qiandongian Qiongzhusi Formation in central Yunnan Province are crucial for understanding the regional stratigraphic evolution.They hold significant implications for constraining the formation of phosphate deposits in the underlying Meishucun Formation,the development of shale gas reservoirs and preservation of the Chengjiang fauna within the Qiongzhusi Formation,and the recognition of depositional environments in the overlying Canglangpu Formation.This study focuses on analyzing sedimentary structures and paleocurrent patterns from the Erjie field profile in the Jinning area,central Yunnan Province,based on detailed field observations.The findings indicate that:(1)The Qiongzhusi Formation in the Jinning area exhibits characteristics of ponded turbidity current deposits,such as repeated Bouma sequences A,recurrent parallel beddings,and relatively thick mudstone caps.(2)Contourite are ubiquitous,associated with bidirectional and unidirectional cross-bedding as well as wave-ripple lamination.(3)Paleocurrent data reveal six dominant and subdominant orientations,forming three nearly opposite pairs:50° vs.213°,111° vs.292°,and 171° vs.341°;and(4)rose diagrams of paleocurrents from individual bidirectional cross-beds display marked asymmetry.Through comprehensive analysis of sedimentary environments,paleogeography,and interactions of sedimentary flows,it is suggested that the Qiongzhusi Formation was likely deposited in a deep-water ponded basin characterized by widespread contour current deposits,as well as internal-wave and internal-tidal deposits induced by deep-water contour currents.关键词
阻塞盆地/等深流沉积/内波、内潮汐沉积/古水流分析/筇竹寺组/滇中地区Key words
ponded basin/contour current deposits/internal-wave and internal-tide deposits/palaeocurrent analyses/Qiongzhusi Formation/central Yunnan Province分类
天文与地球科学引用本文复制引用
李向东,魏泽昳,王丹,杨敏..滇中地区寒武系筇竹寺组阻塞盆地深水等深流引发内波、内潮汐沉积[J].古地理学报,2025,27(5):1173-1188,16.基金项目
昆明理工大学"双一流"建设科技专项(编号:202202AG050006)和国家自然科学基金项目(编号:41272119)共同资助.[Co-funded by the Science and Technology Special Project for Double First-class Construction of Kunming University of Science and Technology(No.202202AG050006)and the National Natural Science Foundation of China(No.41272119)] （编号:202202AG050006）
