Supporting Information for G3 manuscript

The Longmu Co–Shuanghu suture in central Tibet and the Changning–Menglian suture in southeastern Tibet form the boundary between Gondwana and Laurasia. However, the absence of detailed geological evidence in eastern Tibet has made previous correlations speculative. Here we present new geochronological and geochemical data from the major Paleo-Tethyan suture zone in eastern Tibet. 300–284 Ma MORB-type gabbros define the southern segment of the Deqin back-arc suture, and 239 Ma S-type granites represent the southern extension of the North Lancangjiang magmatic belt. The main Paleo-Tethyan suture in eastern Tibet is an island-arc orogen well linked to the Changning–Menglian suture, supporting its role as part of the Gondwana–Laurasia boundary.