摘要
Pyongnam Basin is located in the Central of the Korean Peninsula, Sino-Korean platform. In the Pyongnam Basin, Paleozoic strata are well exposed, especially the Cambrian to Silurian System in the middle-southern basin. However, the Upper Ordovician to Lower Carboniferous strata and fossils had not been found in other districts of Pyongnam Basin except for the Upper Ordovician to Silurian strata in Goksan and Pobdong region. Recently, in the Pyongyang district, the central of Pyongnam Basin, several fossils was newly found from the upper part of Middle Ordovician Series (Mandal Formation) such as Chaetetes cf. nantanensis, Calceola sp., Thamnopora sp., Cladopora sp. and so on. The studies of these fossils suggest that it is possible that the upper part of the Mandal Formation could be Devonian System. This scientific discovery gives a new concept about the paleogeography and geotectonic evolution in the Sino-Korean platform.