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在AMS ~(14)C测年基础上,通过苏北开庄遗址地层的碎屑粒度和氧化-还原敏感元素测试分析,研究了该地区全新世成陆过程。结果表明,在开庄遗址下部的自然沉积地层中,V/(V+Ni)比值所代表的还原程度和碎屑粒度所代表的沉积动力随着钻井深度的减小而呈现先减小后增大的变化,代表该地区经历了海退成陆的环境演变过程,成陆时间为5200aBP前后。其中,第4层(青灰色砂土层10 300~5200aBP)海水呈分层不强烈的厌氧环境,随着剖面深度的减小还原程度减低,沉积物中粗组分减少,沉积动力减弱,且动力组成变得复杂,可能代表水体深度逐渐降低的浅海环境;而第3层(黑色砂土层,5200~3800aBP)还原程度迅速增大并保持稳定,沉积动力增强沉积物中粗组分增加,且动力组成变得更为复杂,代表了海退之后富含有机质而缺氧的沼泽环境。
On the basis of the AMS ~ (14) C dating, the formation process of the Holocene in this area was studied through the analysis of the detrital particle size and oxidation-reduction sensitive element of the Kaizhuang site in the North Jiangsu Province. The results show that the depositional force represented by V / (V + Ni) ratio and the detrital particle size represent the first decrease and the later increase with the decrease of drilling depth in the natural sedimentary formations in the lower part of the Kaizhuang site Large changes, on behalf of the region experienced a retreat into land environmental evolution process, landing time is around 5200aBP. Among them, the seawater in layer 4 (limestone sandy soil layer 10 300 ~ 5200 aBP) is not strongly anaerobic in stratification, decreases with the reduction of the depth of the section, reduces the degree of sedimentation, reduces the coarse components in the sediments and weakens the sedimentary motility, And the dynamic composition becomes complicated, which may represent the shallow sea environment with decreasing depth of water body. However, the reduction degree of Layer 3 (5200 ~ 3800 aBP in black sandy soil layer) rapidly increases and remains stable, and the coarse component in sediment-enhanced sediment increases , And the dynamic composition becomes more complex, representing the swamp environment rich in organic matter and hypoxia after the regression.