ANALOGOUS TECTONIC EVOLUTION OF THE TETHYAN AND SE ASIAN REGIONS

The study of tectonic evolution of the Tethyan and SE Asian regions indicates that these two regions have each passed through southwardly progressing sequences of similar tectonic events. Both regions have experienced a southward island-arc subduction and back-arc spreading leading to continental detachment from Gondwanaland, with an earlier southward island arc subduction of Palaeotethys (Tethyan northern ocean), and continental detachment (Early Devonian) which produced the Neo-Tethys Ocean and the land masses of the Tethyan region, compared with a later southward island arc subduction of Tethys II, and continental detachment (Permo-Triassic) which produced Tethys III, and the land masses of the SE Asian region. The northward subduction of Neo-Tethys (Tethyan southern ocean) and formation of the Alpine Orogeny (Late Paleocene-Pliocene) in the Tethyan region was accompanied by the opening of the Red Sea to the south of the Arabian Gondwanaland. Similarly, the northward subduction of Tethys III (SE Asian southern ocean) (Late Oligocene-Present), and arc-continent collision in the SE Asian region was accompanied by the opening of the Southern Ocean to the south of the Australian Gondwanaland. In both regions, the younger oceans are formed sequentially southward. The later occurrence of the southward progressing sequence of tectonic events in the SE Asian region compared with the similar sequence of tectonic events in the Tethyan region indicates an eastward global migration of tectonic events.