Middle to Late Mississippian and Early Pennsylvanian foraminiferal zonal scheme of South China—a case study from the Youjiang Basin: biostratigraphical and palaeobiogeographical implications

Abstract

Ten foraminiferal zones are proposed in the Youjiang Basin (South China): Pojarkovella, Pojarkovella nibelis-Endothyranopsis compressa, Cribrospira panderi-Eostaffella ikensis, Climacammina, Janischewskina delicata, Eostaffellina decurta, Bradyina cribrostomata, Eostaffellina actuosa-Eostaffellina protvaensis, Plectostaffella and Pseudostaffella antiqua zones. These zones span the interval from the middle Viséan to the late Serpukhovian in a continuous succession, and above, a final zone characteristic of the Severokeltmian Substage in the middle part of the early Bashkirian. These zones are compared with other foraminiferal zones described from China, particularly with those from South China and allow to uniformize the foraminiferal stratigraphical records in the region, and to standardize the foraminiferal zones defined in those regions. The stratigraphical range of some taxa is still debated, but the Viséan-Serpukhovian and the lower-upper Serpukhovian boundaries are well constrained by well-known cosmopolitan taxa. Foraminifers during the lower Middle Mississippian (middle Viséan to the earliest late Viséan) are more similar to the foraminiferal assemblages described from Western Europe, whereas from the upper Middle to Late Mississippian (i.e. latest Viséan-Serpukhovian) are more similar to those in the Russian Platform, and thus, the use of the Russian zonal scheme and biostratigraphy is more practical than to use the biozones defined in Western Europe.