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探讨了河西走廊石羊河终端湖泊——猪野泽晚冰期以来沉积物总有机碳(TOC)、碳氮比(C/N)、有机碳同位素(δ13 C)三种有机地球化学指标之间的关系及古环境意义.结果表明:猪野泽QTH01剖面沉积物TOC指标主要代表湖泊及流域的植被初级生产力;C/N值受到周围区域表土C/N值和沉积物成岩过程的双重影响,总体较低,并不能直接反映植物类型的变化.TOC和C/N相关性较高,相关系数达到0.87;δ13 C与其他两种指标之间均显示出一定的负相关性.TOC和C/N值较高和δ13 C值较低的时期,流域植被初级生产力较高,气候较湿润;反之,流域植被初级生产力较低,气候较干燥.湖泊沉积物中沉积相的改变,往往伴随了沉积环境的剧烈变化,猪野泽沉积物沉积相变化明显,探讨的三种有机地化指标随着沉积相改变变化明显,说明猪野泽沉积物有机地球化学指标的变化也受到沉积相改变的控制.
The relationship between TOC, C / N and δ13C of organic matter in sediments since the Late Pleistocene in the Shiyang River of the Hexi Corridor was discussed Relationship and paleoenvironmental significance.The results show that the TOC index of the Qostan section of the Zeye Zeze mainly represents the primary productivity of vegetation in lakes and watersheds, and the C / N ratio is affected by both the C / N ratio of the surrounding area and the diagenesis of sediments. Low, and can not directly reflect the changes of plant types.TOC and C / N correlation is high, the correlation coefficient of 0.87; δ13 C and the other two indicators showed a certain negative correlation between the TOC and C / N value Higher and lower δ13C values led to higher primary productivity and humid climate, while lower primary productivity and drier climate in the basin resulted in the change of sedimentary facies in sediments of lakes The changes of sedimentary facies of the Porosu-zen sediments are obvious. The three organic geochemical indexes discussed vary with the changes of sedimentary facies, indicating that the changes of the organic geochemical indexes of the Porosu-zen sediments are also controlled by the changes of sedimentary facies.