辽南地区金州西团瓢湖沼相沉积物粒度化学特征及环境意义

Grain-size and chemical characteristics of the lacustrine deposits from the Xi Tuanpiao profile in Jinzhou, southern Liaoning province and their environmental significances

  • 摘要: 湖泊沉积物以其沉积速率快、连续性好、分辨率高等特性成为研究历史时期气候变化的理想载体。辽东半岛南部处于亚欧大陆东岸,保留多处典型的湖相沉积。以辽南地区金州西团瓢湖沼相沉积物为研究载体,通过野外调查与室内粒度、化学元素、烧失量、电导率实验相结合的方法,探讨了该区域的环境变化。结果表明:研究区沉积期气候经历了寒冷干燥(15.64~30.81 kaBP)-寒冷干旱(10.36~15.64 kaBP)-温暖干旱(5.77~10.36 kaBP)-温暖湿润(0.90~5.77 kaBP)-温凉干旱(0.90 kaBP至今)5个阶段,结合地球化学指标的对比分析,初步认为端元1可能指示东亚季风及坡面流水带来的细颗粒沉积物,端元2可能代表动力较低的弱水流沉积物,端元3则可能代表动力较强的冲洪积物。

     

    Abstract: Lake deposits are ideal carriers for study of climate changes in history due to their high deposition rate, good continuity and high resolution. The southern part of Liaodong peninsula lies on the east coast of the Eurasian continent, and some typical Quaternary lacustrine deposits are well preserved there. In this paper, the lacustrine sediments from the western Jinzhou, southern Liaoning province were taken as the research carriers for reconstruction of environmental changes. Field investigation is carried out together with laboratory testing for particle size, chemical composition, ignition loss and electrical conductivity. The results show that the study area has suffered a climate change from cold and drought (30.81~15.64 kaBP) to cold and drought (15.64~10.36 kaBP) to warm and drought (10.36~5.77 kaBP) to warm and humid (5.77~0.90 kaBP) and to cool and drought (0.90 kaBP until now). Combined with the comparative study of geochemical indicators, it is preliminarily believed that the EM1 may indicate the fine particles carried into the lake by wind and flowing water, the EM2 represent a kind of weak fluvial sediments, and the EM3 a strong alluvium deposits.

     

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