摘要
通过对四川盆地上二叠统龙潭组烃源岩典型剖面样品的地球化学分析,从TOC含量、TOS含量、生物标志化合物特征等方面讨论四川盆地上二叠统龙潭组烃源岩地球化学特征及意义。实验数据显示:四川盆地上二叠统龙潭组烃源岩TOC含量、TOS含量在剖面上变化幅度较大,表现出明显的非均质性;上二叠统龙潭组煤和炭质泥岩中正构烷烃主要呈现单峰型,高碳数正构烷烃相对丰度较高,姥鲛烷优势明显;而页岩样品以双峰型为主,低碳数峰群主碳集中在nC17,而高碳数峰群以nC25或nC27为主碳峰,具明显植烷优势。这些实验结果表明龙潭组页岩母质来源主要为低等水生生物和陆源高等植物,而龙潭组煤和炭质泥岩以陆源有机质输入为主,在母质来源特征上与龙潭组页岩具有很大的差别。
Through geochemical analysis of core and outcrop source rocks from the Upper Permian Longtan Formation in Sichuan Basin,organic matter type and redox depositional conditions were discussed through organic carbon and biomarker characteristics.The results show that the content of TOCand TOShas fluctuation in the profile,showing obvious heterogeneity.The n-alkanes in coal and carbonaceous mudstone of Upper Permian Longtan Formation are mainly unimodally distributed with relatively high abundance of high carbon number n-alkanes.However,the n-alkanes in shale of Upper Permian Longtan Formation are mainly bimodally distributed with phytanic advantage,and the main peak of the front mode was at nC17,in contrast,the main peak of the back mode was at nC25 or nC27.These results indicate that the organic matter in Longtan shale is mainly of aquatic and continental organic matter input,whereas the organic matter in Longtan coal and mudstone are terrestrial organic matter input.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2015年第8期1613-1618,共6页
Natural Gas Geoscience
基金
国家重点基础研究发展计划("973")项目(编号:2012CB214701)
中国科学院战略性先导科技专项(编号:XDB10030404)
中国科学院"西部之光"人才培养计划项目
中国科学院"西部之光"联合学者项目联合资助
关键词
页岩
地球化学特征
上二叠统龙潭组
四川盆地
Shale
Geochemical characteristics
Upper Permian Longtan Formation
Sichuan Basin
