The Distribution of Methylated-2-Methyltrimethyltride-Cylchromans and Geochemical Implication in Nenjiang Formation of the Late Cretaceous from
详细信息
- 责任者：Wang Li (State Key Laboratory of Organic Geochemistry ; Guangzhou Institute of Geochemistry ; Chinese Academy of Sciences ; Guangzhou 510640 ; China) ; Song Zhiguang
- 刊名：Geochimica
- 出版年：2010
- 卷期：39(5)
- 关键词：生物标志化合物 ; biomarkers ; 沉积环境 ; sedimentary environment ; 松辽平原 ; Songliao Plain
- 页码：p.469-478
- 图表：8 illus., 30 refs.
- 分类号：0600
- issnNo：ISSN0379-1726
- isbnNo：CN44-1398/P
摘要
The composition and distribution of methyled-MTTCs identified in Late Cretaceous core samples of Nenjiang Formation (K2n1 and K2n2) of SK-1 drilling from Songliao Basin are mainly indicative of the depositional environment of salinity, redox state and their variation on the profile, while bearing no relation with organic matter types, burial depths, maturity. This study also shows that α-MTTC/γ-MTTC (α/γ) ratio is also indicative of the salinity of water environments, as when the α/γ ratio is less than 2, which indicates a mesosaline environment, when a ratio of greater than 15 is indicative of a semi-saline to freshwater lacustrine environments,while a ratio between 2 and 15 is indicative of normal marine-ike salinity environment. The combination of all related indexes and biomarkers suggests that K2n1 and K2n2 were formed under significantly different salinity, as the K2n1 was likely developed under a normal marine salinity-like environment with a short period of mesosaline environment at the top section; while K2n2 was likely developed under a semi-saline to freshwater lacustrine environment with a relative stable salinity.