北黄海沉积物中氮的地球化学特征及其早期成岩作用

Geochemical Characteristics and Early Diagenesis of Nitrogen in the Northern Yellow Sea Sediments

本文首次报道对北黄海沉积物中氮的形态及其早期成岩作用的研究成果。结果表明 ,北黄海沉积物中占主导地位的是细粒度组分 ,其结构和性质直接影响着沉积物中化学元素的形态、含量与分布 ,使自然粒度沉积物中各形态氮的垂向分布与细粒度组分中各形态氮的分布非常相近。在氮的早期成岩过程中 ,粒度也起着非常重要的作用 ,沉积物的粒度越细 ,沉积物中有机氮的分解速率越小 ,即细粒度沉积物中有机氮的分解矿化速率最小 ,易于富集有机氮。对于不同站位的沉积物来说 ,因其沉积速率的差异 ,致使沉积物中各形态氮的埋藏通量有很大差异 ,沉积速率越大 ,沉积物中各形态氮的埋藏通量越大 ,在沉积速率最大的 C4站位 ,各形态氮的埋藏通量最大。

Fine-grained components are the predominant composition in the research area in the northern Yellow Sea core sediment, amounting averagely to 87.03% of natural sediments, and directly affect the form, content and distribution of nitrogen in natural sediments, so that the vertical distribution of nitrogen in natural sediments is similar to that in fine sediments. The grain size of sediments has an important role in the early diagenesis of nitrogen. The finer the sediments are, the smaller the decomposition rate of organic nitrogen will be, i.e., organism was easily enriched in fine-grained sediments. The burial fluxes of various forms of nitrogen are different because of the varying sedimentation rates in different sampling stations. The higher the sedimentation rate is, the grater the burial flux of nitrogen will be. The burial fluxes of various forms of nitrogen are the highest in station C4 where the sedimentation rate is the highest.