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中国沙漠 ›› 2026, Vol. 46 ›› Issue (5): 391-402.DOI: 10.7522/j.issn.1000-694X.2026.00061

• • 上一篇    

九江市蓼花剖面末次冰期中晚期沉积物的地球化学特征及环境意义

刘建伟1(), 孙丽2(), 李志文2,3, 钟颖4, 杨妙文1, 张晓晴1   

  1. 1.佛山大学,环境与化工学院,广东 佛山 528225
    2.佛山大学,建筑与规划学院,广东 佛山 528225
    3.中国科学院地球环境研究所 黄土与第四纪地质国家重点实验室,陕西 西安 710061
    4.东华理工大学 地球与行星科学学院,江西 南昌 330013
  • 收稿日期:2026-03-11 修回日期:2026-05-06 出版日期:2026-09-20 发布日期:2026-11-02
  • 通讯作者: 孙丽
  • 作者简介:刘建伟(2001—),男,广东湛江人,硕士研究生,主要从事流域资源可持续与生态环境治理研究。E-mail: liujw_2001@163.com
  • 基金资助:
    国家自然科学基金项目(41201006);国家自然科学基金项目(41571007);黄土与第四纪地质国家重点实验室开放基金项目(SKLLQG2406)

Characteristics of geochemical and environmental significance in the mid-late of the Last Glacial Period sediments in Liaohua section of Jiujiang, Jiangxi Province

Jianwei Liu1(), Li Sun2(), Zhiwen Li2,3, Ying Zhong4, Miaowen Yang1, Xiaoqing Zhang1   

  1. 1.School of Environment and Chemical Engineering /, Foshan University,Foshan 528225,Guangdong,China
    2.School of Architecture and Planning, Foshan University,Foshan 528225,Guangdong,China
    3.State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi'an 710061,China
    4.School of Earth and Planetary Sciences,East China University of Technology,Nanchang 330013,China
  • Received:2026-03-11 Revised:2026-05-06 Online:2026-09-20 Published:2026-11-02
  • Contact: Li Sun

摘要:

鄱阳湖地区晚第四纪风沙沉积物分布广泛,存在多种沉积相叠覆堆积的地层序列,详细记载了环境演变过程。本文选取九江市星子县蓼花剖面(LH)的沙丘砂-古土壤-湖相沉积序列为研究对象,分析了地质年代、粒度、化学元素含量等指标,探讨了该区域末次冰期中晚期的环境变化特征。结果显示:(1)蓼花剖面常量化学元素以SiO2、Al2O3为主,各沉积相存在较大差异。SiO2含量在沙丘砂层最高,Al2O3、Fe2O3含量在古土壤层最高,CaO、MgO、Na2O含量在湖相层最高。(2)化学蚀变指数(CIA)和A-CN-K三角图指示蓼花剖面整体处于中等化学风化阶段,硅铝铁率(Saf)、淋溶系数(ba)、CIA和Rb/Sr值揭示各沉积相的风化程度为古土壤层>湖相层>沙丘砂层。(3)蓼花剖面形成于末次冰期中晚期(51.7~15.1 ka),气候特征呈阶段性变化:LH11(51.7~42.1 ka)为寒冷干燥期,冬季风增强,对应深海氧同位素MIS3b阶段;LH10-LH6(42.1~27.0 ka)转为温暖湿润期,夏季风增强,对应MIS3a阶段;LH5-LH2(27.0~15.1 ka)再次进入寒冷干燥期,冬季风增强,但存在短暂的暖湿波动,对应MIS2阶段。这些变化与Yangzi洞石笋δ18O、洛川剖面>32 μm颗粒含量记录的冬季风强度和6月30°N太阳辐射总量具有较好的对比性,为探索亚热带季风气候区的环境演变提供了参考价值。

关键词: 蓼花剖面, 沙丘砂-古土壤-湖相沉积序列, 地球化学, 风化程度, 环境演变

Abstract:

Late Quaternary aeolian deposits are widely distributed in the Poyang Lake region, forming multilayer stratigraphic sequences with interbedded sedimentary facies that provide detailed archives of environmental evolution. This study focuses on the dune sand-paleosol-lacustrine sedimentary sequence from the Liaohua section in Xingzi County, Jiujiang City. By analyzing geochronology, grain size, and chemical element content, this research investigates the environmental evolution during the mid-late of the Last Glacial Period in the region. The results show that: (1) Major chemical elements in the Liaohua section are dominated by SiO₂ and Al₂O₃, with significant variations among different sedimentary facies. SiO₂ content is highest in the dune sand layer; Al₂O₃ and Fe₂O₃ contents peak in the paleosol layer; CaO, MgO, and Na₂O are most abundant in the lacustrine layer. (2) The Chemical Index of Alteration (CIA) and A-CN-K ternary diagram indicate that the overall moderate chemical weathering stage of the Liaohua section. The silica-alumina-iron ratio (Saf), leaching coefficient (ba), CIA, and Rb/Sr ratio further indicate that the weathering intensity of different sedimentary facies follows the sequence: paleosol > lacustrine > dune sand. (3) The Liaohua section was formed during the mid-late of the Last Glacial Period (51.7-15.1 ka), with climate conditions displaying phased variations: LH11 (51.7-42.1 ka) was a cold and dry phase with enhanced winter monsoon, corresponding to MIS3b in marine oxygen isotope records; LH10-LH6 (42.1-27.0 ka) transitioned to a warm and humid phase with enhanced summer monsoon, corresponding to MIS3a; LH5-LH2 (27.0-15.1 ka) returned to a cold and dry climate with reinforced winter monsoon, though intermittent warm and moist fluctuations occurred, corresponding to MIS2. These variations show good consistency with winter monsoon intensity inferred from the δ18O of Yangzi Cave stalagmites, the >32 μm grain-size fraction in the Luochuan section, and June solar radiation at 30°N, providing valuable references for exploring environmental evolution in the subtropical monsoon region.

Key words: Liaohua section, dune sand-paleosol-lacustrine sedimentary sequence, geochemistry, chemical weathering degree, environmental evolution

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