Published online by Cambridge University Press: 14 July 2015
An ammonite fauna from the southern coastal volcanic region of the Chinese Jurassic contains representatives of the genera Sulciferites, Coroniceras, Arnioceras, Asteroceras, Eparietites, and Juraphyllites. The ammonite-bearing strata of the Jinji Formation were deposited during the Sinemurian (Bucklandi to Obtusum zones), whereas the lower member has yielded marine Hettangian bivalves. The Jinji Formation is underlain by terrestrial Triassic rocks of the Xiaoping Formation and overlain by terrestrial Middle Jurassic rocks of the Baizushan Group.
Correlative Early Jurassic rocks are shown to occur across eastern Guangdong Province, and probably as far north as southern Hunan Province. Although this marine phase of deposition may correspond broadly to a eustatic sea level rise, the exact role of local tectonic events has still to be assessed.