Ostracod biostratigraphy of Lower Cretaceous lacustrine sequences in northern Hebei, North China: A revision

Abstract

Fluvial-lacustrine deposits are well preserved in the Lower Cretaceous rift basins, such as the Luanping, Sichakou-Senjitu, Qingquan, Huajiying, and Pingquan basins, in northern Hebei, North China. These non-marine strata yield abundant ostracods that serve as useful materials in the chronostratigraphic constraint and stratigraphic correlation. The ostracods of the Tuchengzi, Dabeigou, Dadianzi, Xiguayuan, and Nandian formations from northern Hebei can be divided into the Djungarica-Procyprois-Yixianella-Damonella (Tithonian–Berriasian), Luanpingella-Ocrocypris-Eoparacypris (Valanginian–lower Hauterivian), Cypridea-Timiriasevia-Daurina (upper Hauterivian), Cypridea-Limnocypridea-Lycopterocypris (Barremian–lower Aptian), and Cypridea-Clinocypris-Cyclocypris (upper Aptian) assemblage zones, respectively. This work demonstrates that ostracods are useful for biostratigraphic correlation and age determination in regional, intra-basinal lacustrine deposits. In addition, a preliminarily attempt on the correlation of the ostracod assemblage zones in northern Hebei with those in some typical contemporaneous terrestrial deposits around the world is also discussed.