沉积学报2026，Vol.44Issue(4)：1333-1352,20.DOI:10.14027/j.issn.1000-0550.2025.013
扬子陆块北缘汉中地区成冰纪冰期沉积岩与锆石U-Pb年龄
Cryogenian Sedimentary Rocks and Zircon U-Pb Age in Hanzhong Area,Northern Margin of the Yangtze Block
摘要
Abstract
[Objective]Neoproterozoin"Snowball Earth"(Cryogenian)glaciations is a long-standing hot topic in sedimentology.In South China,well-preserved sedimentary records during Cryogenian Period have been found in many places in the Yangtze Block.However,there are relatively few reports on deposits of this time in Kangdian Rift Basin on western margin of the Yangtze Block,and in the rift basin between northern margin of the Yangtze Block and southern margin of the Qingling Orogen.[Methods]This study focuses on the Cryogenian glacial deposits in the Gangchang-Yuanba section,Hanzhong area,northern margin of the Yangtze Block.Based on the field observations and measurements,zircons were selected from the bottom tuff layer and upper sandstones for U-Pb dating analysis us-ing laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS).Detailed features of the sedimentary rocks and their regional correlation are also discussed.[Results]Two sets of tillites were identified for the first time within the Neoproterozoic glacial sedimentary rocks in this region,both from a continental glacier.Several layers of sandstone and siltstone are presented between and above the tillite sets.Zircons from the bottom tuff yielded the earli-est mean concordant age of(719±11)Ma,indicating the beginning of glaciation in this region.Considering their lithological succession and sedimentary structures,these Cryogenian deposits are thought to have been formed during Sturtian glaciation,corresponding respectively to the Chang'an and Gucheng glaciation periods.The timing of this glaciation event,and the sedimentary associations,are consistent with contemporaneous sediments in the adjacent Zhenba and Chengkou areas,and also show similarities to Sturtian sediments widely distributed in other parts of South China.关键词
扬子陆块北缘/"南沱组"/冰川沉积/Sturtian冰期/锆石U-Pb测年Key words
northern margin of the Yangtze Block/Nantuo Formation/glacial deposition/Sturtian glaciation/zircon U-Pb dating分类
天文与地球科学引用本文复制引用
高悦阳,李红,金佳宁,穆娅榕,李宗霖..扬子陆块北缘汉中地区成冰纪冰期沉积岩与锆石U-Pb年龄[J].沉积学报,2026,44(4):1333-1352,20.基金项目
国家自然科学基金项目(41272115) （41272115）
陕西省自然科学基金项目(2025JC-YBMS-303) （2025JC-YBMS-303）
西北大学高水平教材建设项目 National Natural Science Foundation of China,No.41272115 （）
Natural Science Foundation of Shaanxi Province General Program Project,No.2025JC-YBMS-303 （）
Northwestern University High-Level Textbook Construction Project （）
