Fig. 2

Outcrop photographs of upper Cenozoic deposits on Miyako Jima and Okinawa Jima. a Cavity-filling deposits (arrowed) with terrestrial vertebrate fossils at an outcrop near Nishihara, Miyako Jima. S Shimajiri Group, R Ryukyu Group. Scale bar = 1 m. b Stratigraphic relationship between the Shimajiri Group and the Chinen Formation at the Urizun outcrop in Chinen, southern Okinawa Jima. Dark-gray siltstone (S) of the Shinzato Formation (Shimajiri Group) overlain by light-gray fine-grained siltstone of the lower Chinen Formation (LC), which in turn is overlain by beige bioclastic grainstone of the upper Chinen Formation (UC). Limestone of the Naha Formation (Ryukyu Group) occurs at the top of this outcrop. However, its contact with the Chinen Formation is not observed. Scale bar = 5 m. c Limestone of the Ryukyu Group (R) unconformably overlying siltstone (S) of the Yonahama Formation (Shimajiri Group) at an outcrop near Nishihara, Miyako Jima. Scale bar = 2 m. d Limestones of the Ryukyu Group (the Itoman and Naha formations) unconformably overlying siltstone of the Shimajiri Group at an outcrop ~ 500 m southeast of Yamagusuku, Itoman City, Okinawa Jima. N, Naha Formation; I, Itoman Formation; S, Shinzato Formation. Scale bar = 1 m. e Diagenetically altered limestone of the Itoman Formation (I) overlain by limestones of the Naha Formation (N) at Maehira Quarry near Maehira. The altered limestone is abundant in siltstone blocks derived from the Shimajiri Group. Scale bar = 2 m. f Well-sorted detrital limestone (= bioclastic grainstone) of the Minatogawa Formation (M) unconformably overlying detrital limestone (= bioclastic packstone) of subunit 1R of the Naha Formation (N) at an outcrop located to the southeast of Aragusuku, Yaese Town, Okinawa Jima. Scale bar = 1 m