Integrative Carboniferous stratigraphy, biotas and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

Abstract

During the Carboniferous Period, the Qinghai-Tibetan Plateau and its surrounding areas were located in quite different paleogeographic positions with various sedimentary and biological types. It is important to systematically compile and summarize the Carboniferous strata and biotas of the Qinghai-Tibetan Plateau and its surrounding areas, to establish an integrated stratigraphic framework for correlation, and to reconstruct the paleogeography for correctly understanding the breakup of the Gondwana Continent and the evolution of the Paleo-Tethys Ocean in the Late Paleozoic. The Carboniferous of the Qinghai-Tibetan Plateau and its surrounding areas can be subdivided into the Gondwanan, Cimmerian, and Tethyan types. The Gondwanan-type Carboniferous are distributed in the North Himalayan, Kangmar-Lhunze, and Zanda-Zumba regions of the South Tibet Subprovince and northern India-Pakistan Area, where only the Mississippian is developed and the biota is of Gondwanan affinity. The Cimmerian-type Carboniferous, which are found in the Baoshan, Tengchong, Coqen-Xainza, Lhasa-Zayu, Nagqu-Biru, and South Qiangtang regions, as well as Shan-Thai and South Afghanistan-Pamir areas, also represent only the Mississippian strata, but their biota is characterized by mixed characters of European, South China, Australian, and North American types. The Tethyan-type Carboniferous are distributed in the Tanggula Mountains, Hoh Xil-Bayanhar, Chamdo-Hengduanshan, Tiekelike, West Kunlun, Karakorum, East Kunlun-Central Qinling, and Qilian regions, where the Carboniferous succession is well developed, and the biota is of warm-water Tethyan affinity. The biostratigraphical correlation of the Gond-wanan-type and Cimmerian-type Carboniferous is based mainly on conodonts and additionally on brachiopods and rugose corals. The Mississippian of the Tethyan-type Carboniferous is correlated mainly by using rugose corals and brachiopods, whereas in the Pennsylvanian foraminifera (fusuline) and conodonts are regarded as primary fossil groups, subordinated by rugose corals and brachiopods. Adhering to the International standard chronostratigraphy of the Carboniferous, we have reconstructed a framework of the litho- and biostratigraphic subdivision and correlation of the Qinghai-Tibetan Plateau and its surrounding areas. Further studies should focus on isotope geochronology, geochemistry, paleoclimates, and paleoenvironments of the Carboniferous in the Qinghai-Tibetan Plateau and its surrounding areas.