Closure of the East Paleotethyan Ocean and amalgamation of the Eastern Cimmerian and Southeast Asia continental fragments

When Did the Paleotethys Ailaoshan Ocean Close: New Insights From Detrital Zircon U‐Pb age and Hf Isotopes

“…In addition, Paleo‐Tethyan ocean island and island‐arc volcanic rocks (Permian‐Middle Triassic) are reported along the border between Yunnan and Guangxi (SW China), which indicates that the Ailaoshan Ocean was still subducting until the Middle Triassic (Wu et al, , ). Moreover, recent studies on the Permian‐Triassic clastic rocks in SW China have suggested the presence of a Permian‐Triassic magmatic arc on the northern Paleotethyan margin (Hou et al, ; Wang et al, ; Yang, Cawood, Du, Huang, & Hu, ; Yang, Cawood, Du, Huang, Huang, & Tao, ; Zhong et al, ). For example, studies of the geochemistry of the interbedded clastic rocks in late Permian karstic bauxite deposits in SW China yielded a peak detrital zircon U‐Pb age at ~260 Ma (Hou et al, ).…”

“…Southeast (SE) Asia is located at the tectonic junction among Eurasian, India‐Australian, and Pacific plates (Wang et al, ). The consecutive rifting of various Gondwana‐derived blocks and microcontinents (e.g., South China [Yangtze and Cathaysia], Qiangtang, Indochina, and Sibumasu) from northeastern Gondwana and their eventual accretion onto the southern Eurasian margin had opened and closed three intervening Tethys oceans, that is, Paleo‐Tethys, Meso‐Tethys, and Neo‐Tethys (Figure ; Burrett et al, ; Chen et al, ; Faure et al, ; Metcalfe, ; Xia et al, ; Zaw et al, ).…”

“…The consecutive rifting of various Gondwana‐derived blocks and microcontinents (e.g., South China [Yangtze and Cathaysia], Qiangtang, Indochina, and Sibumasu) from northeastern Gondwana and their eventual accretion onto the southern Eurasian margin had opened and closed three intervening Tethys oceans, that is, Paleo‐Tethys, Meso‐Tethys, and Neo‐Tethys (Figure ; Burrett et al, ; Chen et al, ; Faure et al, ; Metcalfe, ; Xia et al, ; Zaw et al, ). Remnants of these three oceans are preserved in a series of ophiolite belts (Changning‐Menglian, Garzê‐Litang, Ailaoshan and Jinshajiang [China], Song Ma [Vietnam], Nan‐Uttaradit and Chiang Mai‐Inthanon [Thailand], and Bentong‐Raub [Malaysia]; Figure ; Halpin et al, ; Jian et al, ; Metcalfe, , ; Wang et al, ). Among these three Tethyan oceans, the Paleotethys is the least understood due to the pervasive structural deformation by the Meso‐Tethyan and Neo‐Tethyan tectonic events.…”

“…Among these three Tethyan oceans, the Paleotethys is the least understood due to the pervasive structural deformation by the Meso‐Tethyan and Neo‐Tethyan tectonic events. The Paleotethyan Ocean is inferred to be the main ocean between the Eastern Cimmerian and SE Asia continental fragments, and it extends from the European Alps through the Middle East to SW China and Peninsular Malaysia (Metcalfe, , , , ; Wang et al, ). In mainland SE Asia, the Paleotethys comprises two branches (Metcalfe, ; Sone & Metcalfe, ): The main branch is represented by the Changning‐Menglian suture zone, which extends to Longmu Co‐Shuanghu suture in Tibet and Chiang Mai‐Inthanon, Chanthaburi, and Bentong‐Raub sutures in Thailand and Peninsular Malaysia (Barber & Crow, ; Feng & Ye, ; Metcalfe, ; Wu et al, ; Zhong, , ); another branch is now preserved in the Jinshajiang‐Ailaoshan‐Song Ma suture zones, which extend from the SW Yunnan (China) to northwestern Vietnam (Lai, Meffre, Crawford, Zaw, Xue, et al, ; Sone & Metcalfe, ).…”

Direct Paleomagnetic Constraint on the Closure of Paleo‐Tethys and Its Implications for Linking the Tibetan and Southeast Asian Blocks

“…The lower member (T 2 m 1 ) of the Manghuai Formation consists of siltstone, mudstone, and volcano clastic rocks, and the middle and upper members are composed of rhyolites and volcano clastic rocks (T 2 m 2-3 ). This formation records syncollisional magmatic eruptions in a continental margin volcanic arc setting (Wang et al, 2010;Wang et al, 2018). With the aim of quantifying the paleo-configuration of the Paleo-Tethys subduction zone in this region, we have collected samples from volcano clastic rocks (Figures S1b-S1e in the supporting information) and rhyolites (Figures S1f-S1h) in the syncollisional Manghuai Formation.…”