Deciphering the Early Cretaceous transgression in coastal southeastern China: Constraints based on petrography, paleontology and geochemistry
Abstract The occurrence of a transgression in coastal southeastern China during the Early Cretaceous has been debated. This question was addressed here through the use of petrographic, paleontological and geochemical studies of ten representative Lower Cretaceous outcrop sections in the study area. The petrographic results suggest that limestones in the Shipu section of northeastern Zhejiang Province were predominantly deposited in a tidal flat environment. The paleontological study reveals marine red and brown algae in black shales and mudstones of the Yong'an and Chong'an sections of the western Fujian Province. In the biomarker study of black shales and mudstones, the widespread detection of gammacerane, in combination with ratios of tricyclic terpane C 26 /C 25 35 S/C 34 S > 0.8 and hopane C 29 /C 30