有机质供给和保存在烃源岩形成中的控制作用
Controlling Function of Organic Matter Supply and Preservation on Formation of Source Rocks

烃源岩形成研究一直集中于海相盆地的“生产力模式”和“保存模式”之争，湖相盆地研究较少.利用二连盆地烃源岩有机碳、碳酸盐碳同位素、热解参数、还原硫等地球化学分析数据，表征了湖盆古生产力和陆源有机质输入，研究了有机质供给和保存在烃源岩形成中的控制作用，发现不同的湖盆中有机质供给和保存对烃源岩形成的控制作用明显不同.有机质供给量大的湖盆原始有机质含量高，烃源岩形成主要受有机质供给控制，受有机质保存条件影响小，即使在含氧的水底也会有部分有机质来不及氧化而富集形成烃源岩；有机质供给量小的湖盆原始有机质含量低，氧化环境中大部分有机质被降解难以形成烃源岩，只有还原环境下有机质才能得到较好的保存，有机质保存是控制烃源岩形成的主要因素.
The debate on formation of source rocks has been focused on “productivity mode” and “preservation mode” in marine sediments for many years. Based on the datasets of total organic carbon, carbonate carbon isotope, pyrolysis parameters and reduced sulfur of source rocks of Erlian basin, the productivity and terrigenous organic matter input are characterized and then the role of organic matter supply and preservation in the formation of source rocks are discussed. For the lacustrine basin with high organic matter supply, organic matter supply is the main factor controlling the formation on source rocks because there are still source rocks formed by accumulation of residual organic matter even in the oxidizing sedimentary environment. For the lacustrine basin with low organic matter supply, preservation is the main factor controlling the formation on source rocks because the organic matter can only be preserved in reducing environment since it is too rare to be preserved from oxidation