Determation of the Early Carboniferous Shideng Formation and Late Permian Yangbazhai Formation in the Lanping area， western Yunnan

A sequence of Carboniferous－Permian volcanic rock-bearing strata is developed in Shideng－Xiaogela area in the central part of the Lanping－Simao basin． It is mostly in fault contact with surrounding geological bodies and contains scarce fossils； therefore， there were divergent views as to its stratigraphic division and age assignment in the past． The Early Carboniferous conodont fossils and Late Permian plant and brachiopod fossils collected in the 1∶50000 regional survey show an unconformity between the Carboniferous and Permian． So it is divided into the Early Carboniferous Shideng Formation and Late Permian Yangbazhai Formation．