DOI: 10.1016/j.palaeo.2016.05.027
论文题名: Paleoenvironmental reconstruction of the Late Santonian Songliao Paleo-lake
作者: Cao H. ; Hu J. ; Peng P. ; Xi D. ; Tang Y. ; Lei Y. ; Shilling A.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 457 起始页码: 290
结束页码: 303
语种: 英语
英文关键词: Biomarkers
; Late Cretaceous
; Marine incursion events
; Stable isotopes
英文摘要: The Late Cretaceous is often characterized as having a variable greenhouse climate, however, the relatively few continental sites preserving geologic records from this time exist limiting information on terrestrial climate and environments. Worldwide, the Songliao Basin (SLB) of northeastern China is one of the largest Cretaceous-age continental rift basins. Thus, this well-preserved lacustrine deposit provides a unique record of terrestrial paleoenvironmental conditions during the Cretaceous. Here, we report organic geochemical data from Late Cretaceous-age lacustrine deposits (lower Nenjiang Formation) from the eastern side of the SLB. Outcrop samples were collected from the Houjingou section and the following analyses were performed: (1) total organic carbon (TOC) content and isotopic composition, (2) biomarker distribution, including the identification and determination of relative amounts of both aliphatic and aromatic hydrocarbons and steranes, and (3) compound specific stable carbon and hydrogen isotopic compositions of n-alkanes. The biomarker distribution and stable carbon isotopic values (δ13C) of the TOC indicate organic matter (OM) from the uppermost section of the first member of the Nenjiang Formation (Upper K2n1) was mainly sourced from aquatic macrophytes and land plants. In the lower part of the second member of the Nenjiang Formation (Lower K2n2) the biomarker distribution and δ13C of both the TOC and n-alkanes indicate that OM was sourced from a mixture of algae, bacteria, and higher plants. As a result of marine transgression, seawater incursions, indicated by the presence of 24-n-propyl-cholestanes and 24-iso-propyl-cholestanes, occurred episodically in Lower K2n2. The negative hydrogen isotopic composition (δ2H) of short chain n-alkanes in Lower K2n2 indicates an extremely humid environment and it is likely that an influx of freshwater caused large-scale flooding of the Songliao Paleo-lake. High-resolution biomarker and stable isotope records from the Houjingou section demonstrate abrupt environmental changes in the Songliao Paleo-lake following seawater incursions during the Late Cretaceous. © 2016 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68369
Appears in Collections: 过去全球变化的重建
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作者单位: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China; Graduate School of Chinese Academy of Sciences, Beijing, China; China University of Geosciences (Beijing), Beijing, China; Key Laboratory of Exploration Technologies for Oil and Gas Resources, Ministry of Education, School of Earth Environment and Water Resources, Yangtze University, Wuhan, Hubei, China; Department of Geological Sciences, Indiana UniversityIN, United States
Recommended Citation:
Cao H.,Hu J.,Peng P.,et al. Paleoenvironmental reconstruction of the Late Santonian Songliao Paleo-lake[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,457