MOLECULAR FOSSILS AS INDICATORS FOR PALEOENVIRONMENT AND PALEO-CLIMATE FROM RED CLASTIC ROCKS OF MIDDLE JURASSIC-EARLY CRETACEOUS IN JIANMENGUAN, SICHUAN BASIN OF CHINA
Wang Hongmei
Liu Yuyan
Wang Zhiyuan
Abstract：Series of molecular fossils, including n-alkanes, extended tricyclic terpanes, hopanes and regular steranes, have been detected from the red clastic strata of Middle Jurassic-Early Cretaceous in Jianmenguan profile, Sichuan basin in China. These molecular fossils are supposed to be derived from higher plants and aquatic organisms. Their parameters such as low gammaceran abundance, relative higher w(Pr)/w(Ph) and the dominance of C27-ethylcholestane suggest the occurrence of a limnetic, non-reductive continental environment in the study area during Middle Jurassic and Early Cretaceous. C27 and C29 n-alkanes, believed to be related to woody plants, constitute the main high-carbon number n-alkanes in the studied samples, while C31 n-alkane, supposed to be the main n-alkane in herbal plants, does not prevail over C27 and/or C29 n-alkanes in the samples. This suggests the flourishing of woody plants other than grassy plants at that geological time. This kind of vegetation further indicates the existence of a warm and humid climate from Middle Jurassic-Early Cretaceous, a kind of climate favorable for the development of the red basin. This investigation of the red sedimentary rocks shows that the molecular fossils have a high potential in recovering the paleoenvironment, paleo-vegetation and palaeo-climate.
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Publication Date：2001-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 229-234 )