沉积学报2025，Vol.43Issue(1)：76-87,12.DOI:10.14027/j.issn.1000-0550.2023.004
六盘山东部黄土高原冰期—间冰期沉积物锆石U-Pb年龄物源研究
Zircon U-Pb Ages Provenance Research of Glacial-interglacial Sediments from the Eastern Liupanshan Region of the Loess Plateau
摘要
Abstract
[Objective]The Chinese Loess Plateau(CLP)preserves the most widely distributed,thickest,and con-tinuous aeolian dust deposits in the world.Studying the evolution of loess provenance is important for deducing cli-mate change in inland Asia.Predecessors have made a series of achievements,but the Quaternary climate changed quickly during the glacial-interglacial period accompanied by alternating winter-summer monsoon.Therefore,the source of loess is likely to change with the monsoon;however,there is still controversy regarding the change of loess sources in the glacial-interglacial period due to the lack of evidence of continuous strata.[Methods]Therefore,in this study,we collected nine loess-paleosol layers from Luochuan(S0,L1,S1,L2,and S2)and Lingtai(S0,L1,L2 and S2)for detrital zircon U-Pb dating study.Zircon U-Pb ages were determined at the State Key Laboratory of Continental Dynamics,Northwest University.The U-Pb ages of detrital zircons of the samples are displayed in PDP(Probability Density Plot),KDE(Kernal Density Estimate),and CAD(Cumulative Age Distribution)diagrams.By comparing the zircon age combinations between the different layers an potential source regions,we used MDS(multi-dimensional scaling)technology to analyze the data correlation.[Results]Based on the results,the correlation analy-sis of the data using MDS showed that nine samples had better correlation with the loess-paleosol samples,including the Ruoshui River,Western Mu Us Desert,Yellow River,and Songpan and Qaidam Basins.However,we found several differences in the KDE and PDP diagrams and indicating that the main age distribution of the samples was 200-600 Ma and the secondary age distributions were between 900-1 200 Ma,1 800-2 100 Ma,and＞2 700 Ma.The U-Pb age characteristics of the Lingtai and Luochuan samples were similar to those of the Songpan Basin,Ruoshui River,Western Mu Us Desert,and Yellow River samples.The Qaidam Basin and Eastern Mu Us Desert showed different age characteristics with our samples.Thus,the Qaidam Basin and Eastern Mu Us Desert were not the main source area of the loess,and we concluded that the dust material was mainly derived from the northwest mixture source,including northeast of the Tibetan Plateau,Alxa region,and Western Mu Us Desert.In addition,no signifi-cant difference was found between the loess-paleosol layers during the glacial-interglacial period.To avoid errors caused by data volume,we divided the sample data into two units,namely loess and paleosol,for analysis.The cumulative growth trend of the sample age was analyzed using the CAD diagram,and the results showed that there were not enough data differences,suggesting the provenance remained stable between the glacial and interglacial pe-riods.[Conclusions]Based on the above research and analysis,we draw the following conclusions:(1)Affected by Asian climate drought and Tibetan Plateau uplift,the dust material is mainly derived from the northwest mixture source,including northeast of the Tibetan Plateau,Alxa region,and Western Mu Us Desert;(2)The source of loess indicating the glacial-interglacial period did not change significantly.关键词
黄土高原/第四纪黄土/锆石U-Pb年龄/物源示踪Key words
Loess Plateau/Quaternary loess/zircon U-Pb age/provenance identification分类
天文与地球科学引用本文复制引用
范永超,弓虎军..六盘山东部黄土高原冰期—间冰期沉积物锆石U-Pb年龄物源研究[J].沉积学报,2025,43(1):76-87,12.基金项目
国家自然科学基金项目(41372036)[National Natural Science Foundation of China,No.41372036] （41372036）
