Notes on the two Early Cretaceous floras in South Korea

Abstract

In southeastern Korea, Early Cretaceous rocks of non-marine origin are widely distributed in the Gyeongsang Basin. The sediments are divided into the Sindong Group, presumably of early Early Cretaceous age, and the Hayang Group presumably of late Early Cretaceous age. The Sindong Group is further divided into the Nakdong, Hasandong, and Jinju Formations in upward sequence, and the Hayang Group is further divided into the Chilgok, Silla Conglomerate, Haman, Jindong, and Geoncheonri Formations in upward sequence. Numerous fossil plants were recorded from the Nakdong and Haman Formations. The Nakdong flora is of the Mixed-type without angiosperms and the Haman flora (formerly Silla flora) is also of the Mixed-type with various angiosperms. The Early Cretaceous angiosperm sites are in close association with the territories of the Mixed-type floras. Similar trends are represented in the regions of the southern Primorye, southeastern Jilin and Heilongjiang, North China, Mongolia and southwest Japan.