Nonmarine ostracode zonation and long-distance correlation based on analysis of regional ostracode successions in China, Korea, Japan, and Mongolia

Based on field investigations and published literature, regional nonmarine ostracode successions of Cretaceous age have been investigated in Japan, Korea, China, and Mongolia. Analysis of 25 ostracode assemblages from 24 formations has facilitated 17 correlations among 20 formations in East Asia. For these correlations, four new zones of ostracode assemblages in the Lower Cretaceous and two new zones with two subzones in Upper Cretaceous have been established. This is the first useful nonmarine ostracode zonation for long-distance and international correlation among continental deposits in East Asia. Each zone has been evaluated with respect to chronologic age and geographic extent.