【摘要】 对藏南江孜县床得剖面白垩系黑层和红层沉积岩进行的有机地球化学研究表明,黑层有机碳含量高于红层5~10倍,红层和黑层饱和烃主峰碳数分别为nC25和nC23;黑层和红层沉积有机质的母质来源都以水生植物和菌藻类等低等生物为主,陆源有机质的输入非常有限;但饱和烃的分布和主峰碳数的差异可能反映了有机母源物质在种群方面的差异,而这种差异可能主要是水体温度存在差异造成的,即红层发育时期水体温度可能高于黑层沉积时期。而在高温度条件下,水生生物和陆生植物的生长发育受到限制,造成原始有机质产率和有机质沉积保存量低可能是红层沉积岩形成的主要原因。更多还原

【Abstract】 The organic geochemistry study on the black and red-beds of Cretaceous sediments from Chuangde section of Gyangzê in southern Tibet shows that the Organic carbon content of black beds is 5 to 10 times that of red beds, the predominant carbon number of the normal alkane in the black and red bed sediments are nC23 and nC25, respectively; The parent organic matter of both black and red beds was predominantly aquatic plants, and algae and bacteria with minor being terrestrial matter. It is likely that the difference in the predominant carbon number of normal alkane in the black bed and red bed may be indicative to temperature difference during the red bed and black bed sedimentation. It is also suggested that the red bed deposited at a slightly higher temperature than the black bed. Under the high temperature condition, development of marine organism and terrestrial plant were restrained, resulting in the decreasing of reproduction and preservation of original organism during the sedimentation of the red bed.更多还原