Zhang X.Chung S.-L.Lai Y.-M.Ghani A.A.Murtadha S.Lee H.-Y.SUN-LIN CHUNG2019-11-202019-11-20201900917613https://scholars.lib.ntu.edu.tw/handle/123456789/431815Magmatic arcs typically exhibit non-steady-state evolution with episodic flare-ups and lulls, yet the main drivers remain contentious. Situated in the southwest margin of Southeast Asia, Sumatra records a long-lived magmatic arc that is still poorly constrained in age and tempo. Detrital zircon data from Sumatra delineate major arc magmatic pulses at ca. 212, 102-85, 52, and 22-11 Ma. The mid-Cretaceous to early Eocene zircons mostly yield high positive £`Hf(t) values, indicating magma derivation from juvenile sources and matching well with those of the Gangdese batholiths in the southern Lhasa terrane. These similarities substantiate an extended (~6000 km) Neo-Tethyan arc system from southern Tibet to Sumatra that exhibits concurrent magmatic lulls (ca. 150-105 and 85-65 Ma) and flare-ups (ca. 105-85 and 65-40 Ma). The Late Cretaceous magmatic lull coincided with a period of strong regional deformation and increasingly fast northward drift of India, likely attributable to Neo-Tethyan flat slab subduction. Periodic pulses of Neo-Tethyan arc magmatism most likely correlated with repeated steepening and shallowing of slab dip, rather than India-Eurasia convergence rates. ? 2019 Geological Society of America.journal article10.1130/G46172.12-s2.0-85066443442https://www.scopus.com/inward/record.uri?eid=2-s2.0-85066443442&doi=10.1130%2fG46172.1&partnerID=40&md5=e8f1e6e56441e38406732a0f87438f8c