TY - JOUR
KW - andesite
KW - initial opening
KW - Jinshajiang Ocean
KW - oceanic island basalt
KW - seamount/oceanic plateau subduction
KW - Tethys
AU - Yin Liu
AU - Wenjiao Xiao
AU - Brian Windley
AU - Karel Schulmann
AU - Rongshe Li
AU - Wenhua Ji
AU - Kefa Zhou
AU - Miao Sang
AU - Yichao Chen
AU - Xiaoliang Jia
AU - Liang Li
AB - The timing of the initial opening and subduction of the Palaeotethyan Ocean is currently highly debated, in particular regarding the Jinshajiang Ocean in the central Tibetan Plateau. This study presents four well-constrained U–Pb zircon ages (422.4 ± 6.1, 336.4 ± 7.4, 272.3 ± 2.8, and 255.8 ± 3.4 Ma) of mafic blocks in the Jinshajiang Suture. These mafic blocks have a chemical oceanic island basalt (OIB) affinity. These facts, together with previously published data (236 Ma OIBs), may be interpreted as a series of seamounts/oceanic plateaux varying from Late Silurian to Late Triassic, which were accreted early in the subduction–accretion process. An andesite from the Jinshajiang Suture with continental arc characteristics yielded a zircon U–Pb weighted average age of 385.2 ± 6.6 Ma, implying that the subduction initiation may have occurred at least in the Middle Devonian. Our work suggests a long-lived continuous accretion, which also puts an earlier initial opening time than previously thought. Taking into account the above data and integrated with relevant published information, we favour a long-lived accretionary process accompanied with seamounts/oceanic plateaux, which provides robust new evidence for subduction-related continental growth in the central Tibetan Plateau.
BT - Geological Journal
DO - 10.1002/gj.3432
N2 - The timing of the initial opening and subduction of the Palaeotethyan Ocean is currently highly debated, in particular regarding the Jinshajiang Ocean in the central Tibetan Plateau. This study presents four well-constrained U–Pb zircon ages (422.4 ± 6.1, 336.4 ± 7.4, 272.3 ± 2.8, and 255.8 ± 3.4 Ma) of mafic blocks in the Jinshajiang Suture. These mafic blocks have a chemical oceanic island basalt (OIB) affinity. These facts, together with previously published data (236 Ma OIBs), may be interpreted as a series of seamounts/oceanic plateaux varying from Late Silurian to Late Triassic, which were accreted early in the subduction–accretion process. An andesite from the Jinshajiang Suture with continental arc characteristics yielded a zircon U–Pb weighted average age of 385.2 ± 6.6 Ma, implying that the subduction initiation may have occurred at least in the Middle Devonian. Our work suggests a long-lived continuous accretion, which also puts an earlier initial opening time than previously thought. Taking into account the above data and integrated with relevant published information, we favour a long-lived accretionary process accompanied with seamounts/oceanic plateaux, which provides robust new evidence for subduction-related continental growth in the central Tibetan Plateau.
PY - 2019
SP - 961
EP - 977
T2 - Geological Journal
TI - Late Silurian to Late Triassic seamount/oceanic plateau series accretion in Jinshajiang subduction mélange, Central Tibet, SW China
UR - https://onlinelibrary.wiley.com/doi/abs/10.1002/gj.3432
VL - 54
ER -