The Western Ailaoshan Volcanic Belts and their SE Asia connection: A new tectonic model for the Eastern Indochina Block

• Published in: Gondwana research Vol. 26; no. 1; pp. 52 - 74
• Main Authors: Lai, Chun-Kit, Meffre, Sebastien, Crawford, Anthony J., Zaw, Khin, Xue, Chuan-Dong, Halpin, Jacqueline A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2014
• Subjects: Arc/backarc basin; Arc–continent collision; G-Plate tectonic reconstruction; SE Asia; Western Ailaoshan (WAL) Volcanic Belts; Western Ailaoshan (WAL) Volcanic Belts; G-Plate tectonic reconstruction; Arc/backarc basin; Arc–continent collision; SE Asia
• ISSN: 1342-937X; 1878-0571
• DOI: 10.1016/j.gr.2013.03.003

The Western Ailaoshan (WAL) Volcanic Belts mark the western boundary of the South China–Indochina Suture Zone along the Ailaoshan Fold Belt. Geochronological and geochemical evidence suggests that the WAL Volcanic Belts vary in ages and origins, and includes (1) L. Carboniferous–earliest M.-Permian (ca. 300–270Ma) incipient backarc basin magmatism; (2) M. Permian (ca. 265Ma) island arc/mature backarc basin magmatism; (3) early L. Permian (ca. 260–255Ma) WAL–Indochina arc–continent collision and the associated syn-collisional granitic magmatism, as well as subsequent (4) E. Triassic (ca. 250–245Ma) post-collisional magmatism. Regional geological comparison indicates that the post-L. Carboniferous WAL tectonic evolution was closely related to the Eastern Indochina Block. We present a new G-Plate geodynamic evolution model for the Ailaoshan Fold Belt and its surrounding South China–Indochina region, based on new and published U–Pb zircon ages, together with whole rock and Pb-isotope geochemical data. [Display omitted] •We study and systematically reclassify the Western Ailaoshan (WAL) Volcanic Belts.•WAL contains arc/backarc basin magmatism and collision-related magmatism.•A new Eastern Indochina G-Plate tectonic model is presented.