【摘要】 生物标志化合物是指沉积岩或原油和煤中碳—碳骨架稳定的特征化合物 ,它通常是用于油源对比和古沉积环境的恢复。本次研究在地层划分与对比中尝试利用正常甾烷分布的差异 ,研究表明 ,塔里木盆地寒武系—下奥陶统和中上奥陶统的甾烷分布特征完全不同 :前者的 C2 8甾烷含量高于后者 ,正常甾烷的分布是 C2 9>C2 8>C2 7,呈反“L”型分布 ;后者的 C2 7甾烷含量高于前者 ,甾烷的分布是 C2 9>C2 7>C2 8,呈“V”字型分布。寒武系—下奥陶统和中上奥陶统甾烷分布由反“L”型变为“V”型 ,说明生物在演化过程中 ,有机质的来源及化学结构组成发生了明显变化 ,据此可用于塔里木盆地下古生界的地层划分与对比。更多还原

【Abstract】 Biomarkers are stable compounds of carbon-carbon skeleton in the sedimentary rocks or oil,and are usually used in oil correlation and paleoenvironmental reconstruction.An attempt to use biomarkers to divide and correlate strata is made in the paper.The studies show that the regular sterane distribution during the Cambrian—Lower Ordovician in the Tarim Basin was quite different from that during the Middle—Upper Ordovician.The former shows a C 28 sterane content higher than the latter,and the regular sterane has an inverted “L” pattern distribution of C 29>C 28>C 27.The latter has a C 27 sterane content higher than the former and the sterane has a “V” pattern distribution of C 29<C 27<C 28.During the Cambrian—Lower Ordovician and the Middle—Upper Ordovician the sterane distribution changed from the inverted “L” into a “V” pattern,showing that during the evolutionary process of organisms,the organic chemical structure components obviously changed.This may be used in the Lower Paleozoic stratigraphic division and correlation in the Tarim Basin.更多还原