Constraining subduction-collision processes of the Paleo-Tethys along the Changning-Menglian Suture: New zircon U-Pb ages and Sr-Nd-Pb-Hf-O isotopes of the Lincang Batholith
MetadataShow full item record
The Changning-Menglian suture represents a remnant of the main Paleo-Tethys in the Sanjiang Orogen (SW China), and preserves abundant magmatic rocks formed during orogenic processes related to the closure of the Paleo-Tethys. Our geochronology study on granitoids of the Lincang Batholith, a prominent magmatic feature along the Changning-Menglian suture, yields crystallization age of 261±1Ma, 252±1Ma, to 203±1Ma, confirming a multi-stage emplacement of the batholith. The Late Permian granodiorites are medium- to high-K calc-alkaline, metaluminous (A/CNK=0.99-1.10), with high Al 2 O 3 content (14.03wt%), high Mg # (46), high ( 87 Sr/ 86 Sr) i (0.7192-0.7278), negative whole-rock e Nd (t) (-14.7 to -8.5), ( 206 Pb/ 204 Pb) t of 18.199 to 18.791, ( 207 Pb/ 204 Pb) t of 15.714 to 15.765, ( 208 Pb/ 204 Pb) t of 38.500 to 38.851, zircon d 18 O SMOW =7.13‰-8.57‰, and zircon e Hf (t) of -14.8 to +0.4. The Late Triassic granites are characterized by high SiO 2 value (68.52wt%), high Mg # values of 50, with negative Eu anomalies (dEu=0.32-0.78), high ( 87 Sr/ 86 Sr) i (0.7202-0.7424), negative whole-rock e Nd (t) (-15.6 to -10.7), ( 206 Pb/ 204 Pb) t of 18.659 to 18.793, ( 207 Pb/ 204 Pb) t of 15.752 to 15.791, ( 208 Pb/ 204 Pb) t of 38.865 to 38.959, zircon d 18 O SMOW =8.07‰-9.76‰. These geochemical and isotopic features suggest that the primary magma of both Late Permian and Late Triassic granitoids most likely originated from partial melting of the underlying Proterozoic crustal rocks, with limited addition of mantle components. Our new geochronological and geochemical results together with previously published data, suggest that the composite Lincang Batholith records three magmatic episodes related to the Paleo-Tethys evolution, corresponding to subduction (prior to ~252Ma), syn-collisional (250-237Ma), and post-collisional (235-203Ma) stages.
Showing items related by title, author, creator and subject.
Late Permian-Triassic magmatic evolution in the Jinshajiang orogenic belt, SW China and implications for orogenic processes following closure of the Paleo-TethysZi, Jianwei; Cawood, P.; Fan, W.; Tohver, E.; Wang, Y.; McCuaig, T.; Peng, T. (2013)Growth of continental crust involves the complex interplay of subduction zone magmatism, to generate the crust, followed by stabilization through crustal thickening, magmatism and ultimately isolation from the active plate ...
Generation of Early Indosinian enriched mantle-derived granitoid pluton in the Sanjiang Orogen (SW China) in response to closure of the Paleo-TethysZi, Jianwei; Cawood, P.; Fan, W.; Tohver, E.; Wang, Y.; McCuaig, T. (2012)A diverse suite of intermediate to felsic rocks from the Baimaxueshan pluton within the Sanjiang Orogen, SW China, documents the tectonomagmatic history of closure of the eastern Paleo-Tethys and associated arc accretion ...
Zircon U-Pb age and Sr-Nd-Hf isotope geochemistry of the Ganluogou dioritic complex in the northern Triassic Yidun arc belt, Eastern Tibetan Plateau: Implications for the closure of the Garzê-Litang OceanWu, T.; Xiao, L.; Wilde, Simon; Ma, C.; Li, Z.; Sun, Y.; Zhan, Q. (2016)The Triassic Yidun arc belt (YAB) lies between the Jinshajiang suture zone to the west and the Garzê-Litang suture zone to the east, Eastern Tibetan Plateau. To study the YAB can not only help us to better understand the ...