古地理学报2025，Vol.27Issue(4)：853-869,17.DOI:10.7605/gdlxb.2025.025
滇东北羊场磷矿区ZK0816井寒武系梅树村组深水牵引流沉积
Deep-water traction current deposits of the Cambrian Meishucun Formation in Well ZK0816,Yangchang phosphate ore area of northeastern Yunnan Province
摘要
Abstract
The phosphate ore of Meishucun Formation in northeastern Yunnan Province represent an important component in sedimentary phosphate ore along the southwestern margin of the Yangtze block.While their formation is commonly attributed to upwelling currents,the relationship between these upwelling processes and oceanic circultion patterns remains insufficiently studied.This study focuses on the Meishucn Formation in Well ZK0816 from the Yangchang phosphate ore area,Northeastern Yunnan Province.Core data were systematically collected,including detailed lithological descriptions bed by bed,sedimentary successions,structure features,and environmental and facies analysis.The results show that:(1)The Meishucun Formation can be divided into three members and seven submembers from bottom to top.The first,second and third members are composed of phosphorous rock,phosphorite and phosphorous rock,respectively;(2)The sedimentary succession is dominated by thinning-upward pattern,with subordinate bidirectional and waving-upward trends;(3)Overall,the sedimentary structure is dominated by stripped and banded sedimentary structure,showing a transition from regular to irregular and back to regular layering upward;(4)The typical irregular stripped and banded structures forming coarsening-up and then fining-up succession is developed in the first submember of the second member.Additionally,small-scale bidirectional cross-lamination and wavy lamination are developed in the second submember.These findings suggest that:(1)the first,second and third members of the Meishucun Formation were probably deposited in subtidal zone,slope and shelf environments,respectively;(2)Deep-water traction current deposits are developed in the second member which corresponds to the main industrial phosphate ore layer(KT2)in study area.Contour current deposits are identified in the upper slope setting within the first submember,while internal-wave and internal-tide deposits are recognized in the lower slope setting of the second submember;(3)Upwelling currents may have been induced by deep-water traction currents,contributing to vertical mixing of oceanic water mass.关键词
沉积型磷矿/等深流/内波、内潮汐/上升洋流/梅树村组/寒武系/滇东北地区Key words
sedimentary phosphate ore/contour current/internal-wave and internal-tide/upwelling current/Meishucun Formation/Cambrian/northeastern Yunnan Province分类
天文与地球科学引用本文复制引用
李向东,杨敏,魏泽昳..滇东北羊场磷矿区ZK0816井寒武系梅树村组深水牵引流沉积[J].古地理学报,2025,27(4):853-869,17.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）
