黄河中游全新世剖面中N含量分布及其环境意义

Total Nitrogen and Its Environmental Significance at Holocene Profile,the Middle Reaches of the Yellow River

通过对黄河中游全新世LGT和PLG剖面全氮(TN)含量分布的研究发现,全氮在黄土、古土壤中的含量明显不同,古土壤中的全氮含量一般在0.3 g/kg以上,远大于黄土中的含量。而且,全氮含量变化曲线在剖面上呈现出明显的高值和低值交替变化的特征,这种变化与磁化率曲线可进行良好的对比,也与黄土-土壤序列对应良好。认为,全氮可作为一个气候替代指标较好地反映古环境,全氮含量高指示暖湿的生物活动强的气候条件;反之,含量低则指示冷干的生物活动弱的气候条件。

The total nitrogen content in the LGT and PLG profiles in the middle reaches of the Yellow River were studied. The results show the content of total nitrogen is 0.3 g/kg in soil more than in loess. High-low superseded change of total nitrogen content exists in the loess-soil profile. The change of total nitrogen content is in correspondence with magnetic susceptibility curve and the loess-soil sequence. So total nitrogen can be a climatic proxy. High total nitrogen content shows warm -humid elirnatic environment, whereas low total nitrogen content shows cold - dry climatic environment.