Permian brachiopod faunal sequence of the Shan-Thai terrane: biostratigraphy, palaeobiogeographical affinities and plate tectonic/palaeoclimatic implications

Five Permian brachiopod assemblages are known from the Shan-Thai terrane: a Late Asselian-Tastubian cool-water fauna, three "transitional" faunas of Sterlitamakian. Baigendzhinian-Early Kungurian and Kazanian-Midian age, respectively, and a Late Permian (Dorashamian) warm-water Cathaysian fauna. Ages, biostratigraphical correlations and palaeobiogeographical affinities of these faunas are reviewed. It is concluded that Shan-Thai belonged to the Indoralian Province of the Gondwanan Realm in the Asselian-Tastubian, formed an independent province from the Sterlitamakian through to the Midian, and was finally incorporated into the Cathaysian Province in the latest Permian. This marked change in marine provinciality of Shan-Thai during the Permian may be explained either by a plate tectonic model or a model that involves migration (contraction and expansion) of climatic zones or a combination of both models. © 1995.