Subduction initiation of Indochina and South China blocks: insight from the forearc ophiolitic peridotites of the Song Ma Suture Zone in Vietnam

Abstract

The Song Ma region, which is located in the northwestern Vietnam represents the zone of amalgamation between Indochina and South China blocks. Numerous scattered ultramafic rocks occur in this region in association with Early to Middle Palaeozoic greenschists and paragneisses, and all these rocks were subjected to hydrous metamorphism and deformation. Here, we present new field data, mineral chemistry and geochemistry from a suite of hydrated peridotites within the Song Ma region and discuss the tectonic significances of the region. We also combine the available data within the Song Ma region and Indochina–South China blocks to discuss the tectonic evolution of the subduction zone. Based on the results, we suggest that the peridotites from the Song Ma are mantle residues that suffered a high degree of partial melting in a forearc tectonic setting. The present data together with the available data within the Song Ma region and the Indochina and South China blocks clearly represent a southward directed Middle Palaeozoic subduction system. The Middle Palaeozoic subduction and accretion events mark the evolutionary history along an active convergent margin between the Indochina and South China blocks, possibly related to the amalgamation of the Pangaea supercontinent. Copyright © 2015 John Wiley & Sons, Ltd.

Formation and Forward Propagation of the Indosinian Foreland Fold‐Thrust Belt and Nanpanjiang Foreland Basin in SW China

“…The northern Song Chay mélange and southern Song Ma suture zone mark the opening and closure of the paleo-Tethys Ocean (Metcalfe, 1996(Metcalfe, , 2013Trung et al, 2006;Vượ;ng et al, 2013;Zhang et al, 2013Zhang et al, , 2014. The Cenozoic left-lateral movement along the Ailaoshan belt offset South China from the Indochina Block (Faure et al, 2014(Faure et al, , 2016a(Faure et al, , 2016bNgo et al, 2016;Zhang et al, 2013).…”

“…The major structural features in South China include a foreland basin and an intra-Late Triassic angular unconformity, NW-, or WNW striking fold-thrust belt, and greenschist facies metamorphism in the hinterland (e.g., Faure et al, 2014;Hu et al, 2015;H. C. Liu, Wang, et al, 2015;Ngo et al, 2016;Qiu et al, 2017;Shu et al, 2009;Wang et al, 2018;Yang et al, 2018;R. Q. Zhang, Zhou, et al, 2009; Y. Q.…”

Paleogene granite magmatism in the north of the Truong Son belt and implication for crustal evolution

“…Previous studies on regional tectonics have shown that the Indochina was undergone by two mainly tectonics, which is Indochina-South China subduction/collision during the Permian-Triassic (Ngo et al, 2016;Roger et al, 2012) and India-Asia collision commenced during the Cenozoic (Aitchison et al, 2007;Bui et al, 2018;Zhao et al, 2020;Hoang et al, 2016Hoang et al, , 2017. The Cenozoic igneous activities in southeast China and Indochina occurred in two episodes at 42-24 Ma and 16-0 Ma (Fig.…”

“…(3) Late Carboniferous-Early Permian (ca. 310-280 Ma): I-type granite, granodiorite, and diorite were emplaced in the southern Truong Son area (Ngo et al, 2014(Ngo et al, , 2016Pham et al, 2017;Qian et al, 2020) (Pham N.C. et al, 2020;Wang et al, 2016;Tran et al, 2014). A small number of alkaline intrusions in the northern Truong Son terrane have Middle-Late Triassic ages and were formed during the closure of the Song Ma ocean and collision of the South China and Indochina block.…”

Detrital Zircon U‐Pb Age Distribution and Hf Isotopic Constraints From the Terrigenous Sediments of the Song Chay Suture Zone (NE Vietnam) and Their Paleogeographic Implications on the Eastern Paleo‐Tethys Evolution

“…prolongation of the Jingshajiang-Ailaoshan belt (Hieu, Li, et al, 2016;Nakano et al, 2008Nakano et al, , 2010Ngo et al, 2015;Shi et al, 2015;Trung et al, 2006;Vượng et al, 2013;Y. Wang, Qian, et al, 2018;Wen et al, 2015;R.…”