松嫩平原东部典型黑土剖面孢粉组合、时代及其对古气候的指示

    Palynological assemblages of typical black soil profile in the eastern Songliao Plain and their age and its implication for paleoclimatic

    • 摘要: 自然黑土区是环境演化和气候变化的重要地质记录。研究黑土区形成的时代及古气候环境演变, 清楚黑土的形成机制, 对黑土资源的可持续利用、保护东北大粮仓具有重要的意义。在松嫩平原东部海伦地区典型黑土剖面中采集15件孢粉样品进行孢粉学研究, 并对相同层位土壤样品中总有机碳进行了AMS14C测年。系统的分析、鉴定和研究表明, 典型黑土剖面自下而上可划分为2个孢粉组合, 下部孢粉组合以Echinate Asteraceae-Artemisia-Boraginaceae-Pinus为代表, 上部孢粉组合以Pinus-Amaranthaceae-Artemisia为代表。通过AMS14C测年认为, 松嫩平原东部海伦地区典型黑土为中全新世及晚全新世早期的产物。综合元素地球化学、古植物、孢粉分析表明, 松嫩平原东部典型黑土主要形成于中全新世7400 a B.P.以来的大暖期, 形成于松嫩平原温暖半湿润的气候环境, 植被为以草本灌木为主的草原植被。

       

      Abstract: Natural black soil area is an important geological record of environmental evolution and climate change.Studying the formation of the black soil area and the evolution of the paleoclimatic environment, and knowing how the black soil came from, is of great significance for the sustainable use of black soil resources and protecting the large granary in the Northeast.Fifteen sporopollen samples were collected from a typical black soil profile in the Helen area of the eastern Songnen Plain for pollen research, and total organic carbon in soil samples from the same stratum was AMS14C dated.2 sporo-pollen assemblages which represented by Echinate Asteraceae-Artemisia-Boraginaceae-Pinus of lower part and Pinus-Amaranthaceae-Artemisia of upper part were identified from the typical black soil profile after systematical analysis, identification and research.AMS14C dating indicates that the typical black soil in the Helen area of the eastern Songnen Plain is a product of the Middle Holocene and the early Late Holocene.Comprehensive element geochemistry, paleontology, and spore pollen analysis indicate that the typical black soil was mainly formed during the warm period since 7400 a B.P. in the Holocene.Which Formed in the warm and semi-humid climate of the Songnen Plain, the vegetation is mainly grassland vegetation with herbaceous shrubs.

       

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