The Central Ailaoshan ophiolite and modern analogs

Zircon U–Pb ages, Hf isotope data, and tectonic implications of Early–Middle Triassic granitoids in the Ailaoshan high-grade metamorphic belt of Southeast Tibet

“…Recent studies have revealed that the protoliths of the high-grade metamorphic rocks were complex. Neoproterozoic and early Paleozoic protoliths of sedimentary and igneous origins are widespread (Liu et al 2008a, b;Qi et al 2012;Wang et al 2013c;Cai et al 2014) and were intruded by many Permo-Triassic granitoids Qi et al 2010;Searle et al 2010;Lin et al 2012;Lai et al 2014b;Liu et al 2014Liu et al , 2015a. The present study also shows that zircon grains from the Yinjie, Majie, and Yuanjiang granitoids yield Proterozoic and Paleozoic ages (Fig.…”

“…However, the S-type Heping granite (ca. 244 Ma; Lai et al 2014b), also known as the Tongtiange granite (ca. 247 Ma; Liu et al 2015a), in the low-grade metamorphic belt has experienced weak shearing, as only a weak foliation is observed along the northeastern margins of the granitic intrusions (Fig.…”

“…The suture zones represent a subsidiary branch (Zhong 1998;Metcalfe 2006Metcalfe , 2013Jian et al 2009a, b;Hu et al 2015) or a back-arc ocean basin (Metcalfe 2006(Metcalfe , 2013Fan et al 2010) of the main eastern Tethyan Ocean. Several studies have proposed that the initial opening of the Jinshajiang-Ailaoshan-Song Ma Ocean began in the Silurian (Jian et al 2009b;Xia et al 2015) and that oceanic spreading continued from the Late Devonian to the early Permian (Wang et al 2000;Jian et al 2008Jian et al , 2009aZi et al 2012a;Vuong et al 2013;Lai et al 2014b). Based on the existence of a volcano-plutonic arc along the eastern margin of the eastern QiangtangSimao-Indochina block, it is commonly interpreted that the oceanic lithosphere underwent westward subduction from the middle Permian to the Early Triassic (Jian et al 2009a, b;Fan et al 2010;Liu et al 2011;Zi et al 2012b;Lai et al 2014a).…”

“…The extensive volcanic and plutonic rocks to the west of the Ailaoshan suture zone are considered to be the products of the westward subduction of the Ailaoshan oceanic plate beneath the Simao block (Jian et al 2008(Jian et al , 2009aFan et al 2010;Liu et al 2011Liu et al , 2015aLai et al 2014a). Some granitoids, although cropping out to the east of the Ailaoshan suture zone or even within the Ailaoshan high-grade metamorphic belt, have also been attributed to subduction/collision Qi et al 2010;Lin et al 2012;Lai et al 2014b;Liu et al 2014Liu et al , 2015a.…”

The volcaniclastic series from the Luang Prabang Basin, Laos: A witness of a triassic magmatic arc?

“…To the northeast, the Simao Block is separated from the South China Block by the Ailaoshan Suture (Fig. 1B), which is marked by the occurrence of N-MORB and plagiogranite Devonian to early Carboniferous in age (Jian P. et al, 2009a, b;Lai C.-K. et al, 2014a). The closure of the corresponding oceanic domain occurred during the late Permian to the Early Triassic (Jian P. et al, 2009a, b;Lai C.-K. et al, 2014a, b;Liu H. et al, 2014).…”