Comment on “An alternative plate tectonic model for the Palaeozoic–Early Mesozoic Palaeotethyan evolution of Southeast Asia (Northern Thailand–Burma)” by O.M. Ferrari, C. Hochard & G.M. Stampfli, Tectonophysics 451, 346-365 (doi:10.1016/j.tecto.2007.11.065)

Abstract

Ferrari et al. [Ferrari, O.M., Hochard, C., Stampfli, G.M., 2008. An alternative plate tectonic model for the Palaeozoic–Early Mesozoic Palaeotethyan evolution of Southeast Asia (Northern Thailand–Burma). Tectonophysics 451, 346–365. doi:10.1016/j.tecto.2007.11.065.] redefine the “Shan-Thai” terrane in Thailand as a Cathaysian Indochina-derived terrane when this has traditionally been defined and used as a Gondwana-derived continental block, hence introducing unnecessary confusion. In their definition of “Shan-Thai”, they also inappropriately combine oceanic suture zone rocks (the Palaeo-Tethys Inthanon suture) and continental arc rocks (Sukhothai Island Arc system). The Mai Yuam Fault, identified by Ferrari et al. (2008) as the Palaeo-Tethys suture, is in fact a Cenozoic fault and the Palaeo-Tethys suture zone is represented by the Inthanon Suture zone in Thailand which is equivalent to the previously recognised Inthanon zone. The concept of derivation of “Orang Laut” terranes from South China-Indochina by back-arc spreading is innovative but the proposed Permo-Triassic back-arc along the Song Da/Song Ma zone in Vietnam is less convincing. There is little evidence to support the proposed southwards subduction of Palaeo-Tethys beneath eastern Gondwana in the Permian.