摘要
二叠系长兴和茅口灰岩中大量产出的固体沥青可能主要来源于紧邻的龙潭煤层。沥青富含芳烃。在饱和烃中富含高分子量正烷烃,长链类异戊二烯烷烃,甾烷以 C_(29)为主,还检出三种 C_(24)四环萜烷。
Solid bitumens are concentrated in the forms of vein, or irregular spots, or fine grained dispersion within the limestones of Permian Maokou and Changxing groups in Nantong area, Sichuan Pron., China. It is proposed through 'oil-source rock correlation' by biomarkers and stable carbon isotope ratios that the various kinds of bitumens were directly derived mainly from the adjacent coal bed No. 6 of Permian Longtan Group, of which hydrogen-rich vitrinite is abundant in coal materals, in Yanshitai Coal Mine ares. These bitumens and the coal bed are rich in n-alkanes of high-molecular weight and long chain acyclic isoprenoid alkanes in saturate fraction, and possess the predominant C29 component in steranes. In addition, they have low hopane/sterane ratios below unit, and contain C19-C29 tricyclic terpanes and C29-30 4-methyl steranes, which means a microbial contribution. The difference of biomarkers between these bitumens and the coal bed is in C24 tetracyclic terpanes. There are three C24 tetracyclic terpanes detected in these solid bitumens, however only a common 17, 21-secohopane is found in the coal bed, two other ones which are possibly secotriterpanes with characteristic mass fragments, e.g. m/z:109, 123, 191 (major peak), 315 (M - 15), 330 (M+)are not existed in the coal bed. Therefore, other sources besides the Longtan coal bed can not be excluded for these solid bitumens.
出处
《地质科学》
CAS
CSCD
北大核心
1992年第A12期178-189,共12页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
中国科学院项目"中国石油
天然气成因理论及应用"
"煤与瓦斯突出预测和冶理研究"的部分研究成果
关键词
石灰岩
沥青
来源
二叠纪
长兴组
Solid bitumen, Coal, Biomarkers, Permian, Limestone.
