摘要
本文研究了昆明盆地等淡水湖盆沉积物中烷烃和脂肪酸在早期成岩阶段的分布特征。结果表明,在泥、软褐煤等各类沉积物中,饱和烃主峰多为nC29或nC31,水生低等植物（如硅藻）也可能是高碳数正烷烃生源物的重要来源。烷烃的组成分布基本格局,在500m埋深范围内变化不大,具有一定的稳定性。类异戊二稀烷烃含量很低,但干酪根热解色谱表明其前身物是丰富的,主要缔合于干酪根结构之中。正脂肪酸碳数分布与沉积物类型关系密切,其偶奇优势的消失是一个很缓慢的过程。烷烃和脂肪酸的碳数分布特征没有显示二者在成因上的联系。
Organic matter of fresh water sediments in Kunming Lake Basin, Yunnan, China, has been studied.
Hydrocarbons and fatty acids formed during early diagenesis stages are systematically classified.
1.The main peak cabon number of saturated hydrocarbon in peat,soft brown coal and mud is C_(20) or C_(31).A big variety of high carbon number n-alkanes were formed during the early diagenesis stages.Aquatic plants such as diatoms might also be source of high carbon number n-alkanes.
2.The distribution of n-alkane components is relatively stable from 0 to 500m depth.No obvious variation has been observed.
3. Content of isoperoids in chloroform extractions is low, but thermal spectrum of kerogen degradation shows abundant precursors of isoperoid products.
4.The main peak of mono-n-fatty acids in sediments is nC_(28:0) or nC_(26:0). The distribution of carbon numbnr is in close association with types of sediments.The Even over Odd preference is distinct and disappears only over along process.
5.The distribution of di-n-fatty acids is similar to the mono-n-fatty acids. But the Even over Odd preference of the di-n-fatty acids is less distinct and quickly disapears with increase of depth.
出处
《矿物岩石》
CAS
CSCD
1989年第1期92-99,共8页
Mineralogy and Petrology
基金
中科院地化所开放实验室自然科学基金课题(OGL—85—06)部分研究成果。
