TY - CHAP
T1 - Zircon U–Pb geochronology and Hf isotopic compositions of igneous rocks from Sumatra
T2 - implications for the Cenozoic magmatic evolution of the western Sunda Arc
AU - Lai, Yu Ming
AU - Liu, Ping Ping
AU - Chung, Sun Lin
AU - Ghani, Azman A.
AU - Lee, Hao Yang
AU - Quek, Long Xiang
AU - Li, Shan
AU - Roselee, Muhammad Hatta
AU - Murtadha, Sayed
AU - Lintjewas, Lediyantje
AU - Iizuka, Yoshiyuki
N1 - Publisher Copyright:
© 2023 The Author(s).
PY - 2024/1/15
Y1 - 2024/1/15
N2 - Sumatra is located at the western end of the Sunda Arc, which resulted from the subduction of the Indo-Australian Plate beneath the Eurasian Plate. In this study, we report detailed zircon U–Pb and Hf isotope data for Cenozoic igneous rocks from the entire island of Sumatra to better constrain the temporal and spatial distribution of arc magmatism. The new dataset, combined with literature information, identifies the following two magmatic stages: (1) Paleocene to Early Eocene (66–48 Ma) and (2) Early Miocene to Recent (23–0 Ma), with a 25 myr-long period of magmatic quiescence in between. The magmatic zircons show predominantly pos-itive and high εHf(t) values, ranging from +19.4 to +7.1 in western Sumatra, +17.1 to +1.6 in central Sumatra and +18.0 to +7.0 in eastern Sumatra, indicating an isotopically juvenile magma source in the mantle wedge along the western Sunda Arc. We explain the negative and low εHf(t) values (+0.5 to −13.1) of young samples around the supervolcano Toba as evidence for the subduction of sediment. We argue for a change in the sub-duction processes, where the first magmatic stage ceased owing to the termination of the Neo-Tethyan subduction and the following stage corresponded to the modern Sunda subduction.
AB - Sumatra is located at the western end of the Sunda Arc, which resulted from the subduction of the Indo-Australian Plate beneath the Eurasian Plate. In this study, we report detailed zircon U–Pb and Hf isotope data for Cenozoic igneous rocks from the entire island of Sumatra to better constrain the temporal and spatial distribution of arc magmatism. The new dataset, combined with literature information, identifies the following two magmatic stages: (1) Paleocene to Early Eocene (66–48 Ma) and (2) Early Miocene to Recent (23–0 Ma), with a 25 myr-long period of magmatic quiescence in between. The magmatic zircons show predominantly pos-itive and high εHf(t) values, ranging from +19.4 to +7.1 in western Sumatra, +17.1 to +1.6 in central Sumatra and +18.0 to +7.0 in eastern Sumatra, indicating an isotopically juvenile magma source in the mantle wedge along the western Sunda Arc. We explain the negative and low εHf(t) values (+0.5 to −13.1) of young samples around the supervolcano Toba as evidence for the subduction of sediment. We argue for a change in the sub-duction processes, where the first magmatic stage ceased owing to the termination of the Neo-Tethyan subduction and the following stage corresponded to the modern Sunda subduction.
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U2 - 10.1144/SP537-2022-199
DO - 10.1144/SP537-2022-199
M3 - Chapter
AN - SCOPUS:85179089427
T3 - Geological Society Special Publication
SP - 455
EP - 478
BT - Geological Society Special Publication
PB - Geological Society of London
ER -