中文摘要：

柯坪地区中上奥陶统萨尔干页岩和印干页岩是塔里木盆地两套重要烃源岩,前人研究结果表明其游离态生物标志物含量极低,给精细的油源对比研究带来困难,因而本文采用催化加氢裂解的方法加以研究。相比常规索式抽提,少量干酪根的氢解反应可以获取足量准确的生物标志物信息,这主要跟氢解反应中高温供能、氢气保护、催化剂催化以及干酪根网格对其内部小分子的保护有关。高成熟演化和二叠纪岩浆热液活动的破坏作用,不是萨尔干页岩和印干页岩中游离态生物标志物含量少的主要原因。柯坪地区中上奥陶统属较特殊的台缘斜坡、半闭塞-闭塞海湾沉积或深水陆棚-盆地沉积,在此特定沉积环境下发育的疑源类及其他中、低等生物类等母质输入,是造成游离态生物标志物含量极低的主要原因。

英文摘要：

Salgan and Yingan Shales in Keping region,the source rocks of middle and upper Ordovician in Tarim Basin,northwestern China,were characterized by very low quantities of free biomarkers in traditional Soxhlet extracts,and general steranes and hopanes cannot be detected even in the SIM mode,which makes it difficult to find out the usual oil and source rock correlation.Thus,catalytic hydropyrolysis for kerogens of these source rocks was conducted in order to explore more geochemical information.The results illustrated that little kerogen could display enough and complete biomarker information,which is contributed by high energy at high temperature,protection from H 2 and catalysis from MoS 2,as well as protection supplied by kerogen grid structure.High maturity and magmatic hydrothermal influence were not responsible for the low quantities of free biomarkers.The Keping region in the Ordovician period belongs to platform edge slope and restricted-blocking gulf fancies or deep water shelf-basin face.This special depositional environment is in favor of the input of acritarchs and other related materials but not in favor of the rest biological inputs.As a result,little free biomarkers could be detected in conventional Sohxlet extracts for related acritarchs parent materials.