二连盆地氧化——还原程度和沉积速率对有机质保存的影响

The Impact on Organic Matter Preservation by the Degree of Oxidation and Reduction and Sedimentation Rates of Erlian Basin

沉积环境的氧化—还原程度和沉积速率是影响有机质保存的重要因素。以中国北部的二连盆地为研究对象探讨了氧化—还原程度和沉积速率对有机质保存的影响,发现二者均明显影响着有机质的保存:还原性越强越有利于有机质保存,沉积速率越大越有利于有机质的保存。综合分析发现有机质的保存并非受单一因素控制,氧化—还原程度偏氧化的凹陷中如果沉积速率较高,有机质快速埋藏可以缩短有机质的降解时间,从而使有机质也能得到较好的保存;沉积速率低的凹陷中如果氧化—还原程度偏还原,有机质也能得到较好的保存。有机质保存受氧化—还原程度和沉积速率的综合影响,它们在有机质的保存中起到"相互补充"的作用,单一通过氧化—还原程度或沉积速率分析有机质的保存程度是片面的。

The degree of oxidation and reduction of sedimentary environment and sedimentation rates are two vital factors impacting the preservation of organic matter. The author has attempted to study their impaction by instance of Erlian Basin in northern China and found that the strong reducing environment and high sedimentation rates are favorable for the preservation of organic matter. By comprehensive analysis, the author found that the preservation of organic matter is not controlled by a single factor,for example in some sags with their sedimentary environments proximal to oxidation, if the sedimentation rates were higher,the rapid burial of organic matter could shorten the time of degradation;in other sags with lower sedi- mentation rates, if their sedimentation environment was reducing, organic matter can also be well preserved. In summary, the preservation of organic matter is affected synthetically by the degree of oxidation and reduction and sedimentation rates. They play a role of ＂mutual complementation＂ during the preservation of organic matter. Previous research on the preservation of organic matter only analyzed single factor such as the degree of oxidation and reduction or sedimentation rates, which is somewhat partial.