沉积学报2025，Vol.43Issue(1)：63-75,13.DOI:10.14027/j.issn.1000-0550.2023.014
河流过程对小型集水区沉积物地球化学与重矿物组成的影响
Effects of Fluvial Processes on Sediment Geochemistry and Heavy Mineral Composition in a Small Catchment:A case study of the Balan River
摘要
Abstract
[Objective]River sediments record abundant information about their source,which is significant for ex-ploring weathering,the transport-sedimentation cycle and parent rock composition in the source region of the basin.Unlike large watersheds that may integrate a range of weathering mechanisms and contain complex rock types,small rivers have similar climatic and lithological backgrounds,which provides valuable information when studying sedi-ment composition.[Methods]In order to explore the influence of fluvial processes on sediment composition,eight samples were obtained from the upper and lower of the Balan River for granular processing(＜63 µm,63-125 µm,125-250 µm).The＜63 µm samples were subjected to geochemical testing(major,trace,rare earth and Sr-Nd isotopes).The 63-125 µm and 125-250 µm samples were tested for heavy minerals.[Results]It was found that the sediments in the Balan River have undergone low chemical weathering,are of low maturity,and are in the primary cycle of deposition.The provenance is mainly from felsic parent rock.The provenance indices(La/Sc,Co/Th,Cr/Th,Th/Sc)and Sr-Nd isotopic compositions showed little change overall,which represents the overall characteristics of the Balan River basin.[Conclusions]The Balan River samples showed consistent chemical weathering,maturity lev-els,recycling characteristics and host rock properties,indicating that the fluvial process had not significantly affect-ed their geochemical composition.The heavy minerals were diluted and mixed after river transport;those from differ-ent river reaches and with different grain size fractions showed obviously different compositional content.This indi-cates that short-distance transport is unlikely to evenly distribute heavy minerals within different grain size fractions.Therefore,when studying river source-sink systems,a small number of samples does not necessarily represent the heavy mineral composition of the entire basin,even in small rivers.This study also emphasizes that the combination of Sr-Nd isotope and inactive element ratio can be used effectively for river provenance tracing.关键词
巴兰河/河流过程/地球化学组成/重矿物/Sr-Nd同位素Key words
Balan River/fluvial process/geochemical composition/heavy mineral/Sr-Nd isotope分类
天文与地球科学引用本文复制引用
赵慧莹,谢远云,迟云平,康春国,吴鹏,孙磊,魏振宇..河流过程对小型集水区沉积物地球化学与重矿物组成的影响[J].沉积学报,2025,43(1):63-75,13.基金项目
国家自然科学基金项目(42171006,41871013)[National Natural Science Foundation of China,No.42171006,41871013] （42171006,41871013）
