铀矿地质2026，Vol.42Issue(3)：430-439,10.DOI:10.3969/j.issn.1000-0658.2026.42.032
四川盆地北部苍溪组含铀层系沉积特征及沉积期古气候特征研究
Sedimentary Characteristics and Paleoclimate Features of Uranium-bearing Strata of Cangxi Formation in Northern Sichuan Basin
摘要
Abstract
Based on the principles of sedimentary systems and facies,this paper conducts a comprehensive analysis of the sedimentary characteristics and paleoclimate of Cretaceous red beds in northern Sichuan Basin with the methods of field outcrop observation,drilling data analysis,and sporopollen fossil analysis.The results show that Lower Cretaceous Cangxi Formation vertically developed a"dual structure"with coarse grains in the lower part and fine grains in the upper part.Horizontally,four main types of sedimentary facies were developed:alluvial fan facies,braided river facies,meandering river facies,and littoral-shallow lacustrine facies.The sedimentary environment favorable for sandstone-type uranium mineralization is primarily sandy braided river deposits.The known uranium mineralization and uranium ore bodies are mostly hosted in paleo-scour troughs,mainly distributed in Cangxi-Wangcang-Nanjiang-Tongjiang area.Based on the types and assemblage characteristics of sporopollen fossils from Cangxi Formation,the sporopollen assemblage is characterized by the abundant presence of Classopollis and a small amount of Dicheiropollis,which basically constrains the age of Cangxi Formation to Valanginian to Hauterivian stages.Combined with the plant community dominated by Cheirolepidiaceae and the presence of charcoal-rich organic matter in the light-colored rhythmic layers of Cangxi Formation,this study indicates that the climate environment in northern Sichuan Basin during Early Cretaceous was characterized by an alternation of arid and humid climate.Specifically,the lower part of each rhythmic layer of Cangxi Formation represents warm and humid(or subaqueous)light-colored deposits,while the upper part represents red beds(floodplain deposits)formed under an arid climate.关键词
沉积特征/孢粉组合/干湿交替/砂岩型铀矿/苍溪组/四川盆地Key words
sedimentary characteristics/sporopollen assemblage/arid-humid alternation/sandstone-type uranium deposit/Cangxi Formation/Sichuan Basin分类
天文与地球科学引用本文复制引用
张富平,侯学文,熊鸿鸽,张亮..四川盆地北部苍溪组含铀层系沉积特征及沉积期古气候特征研究[J].铀矿地质,2026,42(3):430-439,10.基金项目
中国核工业地质局区域评价项目(编号:201365)资助. （编号:201365）
