全新世中后期开封西郊黄泛沉积序列的孢粉记录

发布时间：2018-07-28 15:42

【摘要】：历史时期以来,黄河在开封市附近多次泛滥形成了相对完整的沉积序列。选取开封市西郊25 m岩芯(ZKjm)为研究对象,通过孢粉分析,结合地层沉积旋回和历史文献资料,探讨了全新世中后期以来大洪水事件的孢粉记录。结果表明:黄泛地层中的孢粉含量及其组成很好地记录了大洪水事件,洪水沉积期的木本植物花粉含量高于其间断期,而人工禾本科花粉含量低于间断期。每个粒度旋回基本上都有与之对应的孢粉亚带,且其上下界限的吻合度较高,表明孢粉可作为划分沉积旋回的代用指标。岩芯孢粉亚带的数目(12个)多于粒度旋回数目(9个),孢粉组合特征可以识别出规模较小的洪水或者一次洪水事件出现的多个短期洪水间歇期所形成的沉积,孢粉指标划分沉积旋回的精度高于粒度指标。
[Abstract]:Since the historical period, the Yellow River flooding near Kaifeng City many times formed a relatively complete sedimentary sequence. Taking the 25m core (ZKjm) in the west suburb of Kaifeng as the research object, the sporopollen records of the major flood events since the middle and late Holocene were discussed through sporopollen analysis, combined with the stratigraphic sedimentary cycles and historical documents. The results show that the pollen content and its composition in the Yellow River pan-stratigraphic strata can well record the flood events. The pollen content of woody plants in flood deposition period is higher than that of intermittent period, while the pollen content of artificial Gramineae is lower than that of intermittent period. Each granularity cycle basically has corresponding sporopollen subzone and its upper and lower boundary is in good agreement, which indicates that sporopollen can be used as a substitute index to divide sedimentary cycle. The number of sporopollen subzones (12) is more than the number of granularity cycles (9). The sporopollen assemblage features can identify the deposits formed by smaller floods or several short periods of flood intermission during a single flood event. The accuracy of sporopollen index is higher than that of granularity index.
【作者单位】：河南大学资源与环境研究所;黄河文明传承与现代文明建设河南省协同创新中心;
【基金】：国家自然科学基金项目(41171409) 教育部人文社会科学重点研究基地重大项目(12JJD790023);教育部和河南省共建河南大学项目(SBGJ090101) 河南大学研究生优秀学位论文培育计划项目(Y1424004)~~
【分类号】：P534.632;Q914

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