地质学报2026，Vol.100Issue(8)：2851-2869,19.DOI:10.19762/j.cnki.dizhixuebao.2025364
松花江流域河流沉积物碎屑锆石U-Pb年龄对物源示踪的启示
Implications of detrital zircon U-Pb ages in the sediments of the Songhua River basin for provenance tracing
摘要
Abstract
River sediments are widely regarded as essential archives for source-to-sink system analysis and paleogeographic reconstruction,yet their provenance signals can be substantially altered during downstream transport by tributary dilution and heterogeneous zircon fertility.Traditional provenance studies frequently overlook these factors,which can lead to biased interpretations.In the Songhua River basin,the mechanisms through which tributary inputs influence detrital zircon age variations in the mainstream,as well as the quantitative assessment of their sedimentary contributions,remain poorly constrained.In this study,detrital zircon U-Pb geochronology was conducted on sediments from the Songhua River mainstream and its major tributaries,including the Nenjiang,Jilin Songhua,and Lalin rivers.By integrating a dilution index,zircon yield correction,and inverse Monte Carlo modeling,this study evaluates the source-to-sink system of the Songhua River basin.The detrital zircon age spectra are defined by four principal age populations:202～110 Ma,523～205 Ma,2066～1564 Ma and 2747～2341 Ma.Both tributary dilution and differences in zircon yield exert substantial control on zircon age distributions.The effects of tributary dilution gradually diminish with increasing transport distance,whereas zircon-yield correction effectively mitigates biases arising from variations in zircon fertility among source rocks.Two recommendations for provenance studies are proposed:① sampling sites should avoid river confluence zones and preferably be located at least 50～100 km downstream from confluences;and ②zircon-yield correction should be prioritized to enhance the accuracy of provenance assessments.Zircon reproducibility tests demonstrate the absence of～1800 Ma ages in detrital zircon records from the Jilin Songhua River,suggesting that reliance solely on prominent age peaks is insufficient to fully capture regional magmatic-tectonic events.By integrating tributary dilution and zircon-yield controls and combining detrital and igneous zircon datasets,this study addresses the limitations of single-indicator provenance methods and establishes a more robust framework for sediment provenance tracing and paleogeographic reconstruction in the Songhua River basin.关键词
松花江流域/河流沉积物/锆石U-Pb年龄/支流稀释/锆石产率/锆石可再现性Key words
Songhua River basin/river sediment/zircon U-Pb age/tributary dilution/zircon fertility/zircon reproducibility引用本文复制引用
刘思宁,张艳,孙磊,刘海金,王艳茹,谢远云,魏振宇,汪烨辉,祁昊东,吴鹏..松花江流域河流沉积物碎屑锆石U-Pb年龄对物源示踪的启示[J].地质学报,2026,100(8):2851-2869,19.基金项目
本文为黑龙江省自然科学基金项目(编号ZD2023D003)、国家自然科学基金项目(编号42171006)和哈尔滨师范大学学术创新项目(编号XKB202314)联合资助的成果. （编号ZD2023D003）
