Permian sequence stratigraphy and sea-level changes in southwestern China

The Permian strata in southwestern China may be divided into two second-order sequences and eleven third-order sequences representing eleven third-order cycles of sea-level changes, of which six cycles, i. e. early Leonardian, early Guadalupian, late Guadalupian, early Kazanian,early Tatarian and late Tatarian sea-level cycles may be correlated with those in Euramerica. The results of research in this paper show that the Permian relative sea-level changes in the study area are dominantly controlled by global sea-level changes and synsedimentary tectonism, and reverse to those in Euamerica,even in Pangea, where the sea-level changes are characterized by the sea-level rises representing the transgressive sedimentary carbonate sequences. Two types or branches may be recognized for the Permian part of the Phanerozoic sea-level curves:one is the so-called Tethys type or South China type characterized by the sea-level rises representing transgressive sedimentary carbonate sequences;another is so-called classic type or Euramerica type characterized by the sea-level falls representing transitional-regressive sedimentary carbonate sequences. The authors contend that the Permian transgressive global sea-level curves should be represented by those for South China.