Palaeobiogeography of Kazanian-Midian (Late Permian) western Pacific Brachiopod faunas

A data matrix of the presence/absence occurrence data of 129 genera from 16 faunal stations (selected from 19 initially compiled faunal stations on the basis of sampling and study adequacies) is analysed by cluster analysis, nonmetric multidimensional scaling, principal coordinate analysis and minimum spanning tree. Three core faunal groups are revealed and interpreted as representing three biotic provinces. They are the Verkolyma Province embracing the Kolyma Massif, Verchoyan Mountains, east Zabaikal and northern Mongolia; the Cathaysian Province of Japan, northern and southern China and the Indo-China block; and the Austrazean Province of eastern Australia and New Zealand. The overall evolving pattern of Permian marine provincialism of the western Pacific is summarized from our previous, as well as current studies, on the basis of three discrete time slices: Asselian-Tastubian, Baigendzhinian-Early Kungurian and Kazanian-Midian. An attempt is also made to explain the marked change of marine provinciality during the Permian in the western Pacific in the context of plate tectonics, transgression/regression and climatic amelioration.