In the past 20+ years, I have continuously played as a leader in the CREATE (Comprehensive Research on East Asian Tectonic Evolution) integrated project supported by NSC (now: MOST; Ministry of Science and Technology), Taiwan and applied geochronological, geochemical and isotopic techniques to study important petrogenetic and tectonic problems in Asia. For example, I have been, and am still, working on an Academic Pioneering Research Project (學術攻頂計畫) entitled “Tibet & Beyond (II): A Geochemical Perspective on Asian Orogeny and Continental Tectonics” (2016-2021), which is proposed on the basis of the successful Phase I project for a comparative investigation of two active and presumably most important continental collision zones, i.e., the Tibet/Himalaya and the Caucasus/Iran/Anatolia (CIA). A major result we have obtained was the age and geochemical dataset, demonstrating that the eastern Tethyan “collisional” orogenic belt was preceded in many parts by accretionary orogeny that, as well documented in the Central Asian Orogenic Belt (CAOB), has formed substantial amount of juvenile (arc) continental crust. In other words, both the eastern Tethyan and Central Asian orogenic belts appear to have started from an accretionary system and ended up with a collisional system.The two “collisional” Tethyan orogens, i.e., Tibet and CIA, were preceded by accretionary orogenic processes that not only had produced a substantial amount of juvenile continental crust but also fulfill the “orogenic cycle” evolving from an accretionary into a collisional regime. Our geochemical data reveal that, in contrast to generating large portions of juvenile crust in the early, accretionary stages of orogenic development, crustal recycling plays a more important role in the later, collisional stages. The latter, as exemplified in SE Turkey and southern Tibet, involves addition of older continental crust material back into the upper mantle, which subsequently melted and caused compositional transformation of the juvenile crust produced in the accretionary stages. Similar features are observed in young volcanic rocks from eastern Taiwan, i.e., the northern Luzon arc and part of the complex and active subduction/accretion/collision system in South East Asia (SEA) that should evolve one day to resemble the eastern Tethyan and central Asian orogenic belts by collision with the advancing Australian continent.
