Paleozoic convergence processes in the southwestern Central Asian Orogenic Belt: Insights from U–Pb dating of detrital zircons from West Junggar, northwestern China

Subducted oceanic slab break-off in a post-collisional setting: Constraints from petrogenesis of Late Carboniferous dykes in central West Junggar, Xinjiang, NW China

“…(3) Late Carboniferous collisional events between different tectonic blocks (e.g., Yili-Chinese central Tianshan block and Junggar terrane along the Chinese north Tianshan suture zone) (Zhang et al 2016; Han & Zhao, 2018) in northern Xinjiang, led to the closure of the West Junggar remnant ocean basin and other sub-oceans of the Palaeo-Asian Ocean (Han & Zhao, 2018). The final closure of the Junggar Ocean likely occurred at the end of the Late Carboniferous in response to regional amalgamation events in the southwestern CAOB, representing the final assembly of the Kazakhstan Orocline (Zhang et al 2021a). (4) Undeformed mafic – intermediate dykes dissect the deformation structures including folds and faults, which were correlated with subduction-accretionary process in Early Carboniferous, present that the cessation of subduction-accretionary process when the abundances of dykes were emplaced (Zhan et al 2015).…”

“…Delamination may produce non-linear diffuse distribution of magmatism in a large area, whereas the magmatism caused by slab break-off will be confined to a narrow linear zone with significant crustal uplift (Whalen et al 2006; Liu et al 2017). The spatial-temporal pattern of Carboniferous magmatism in West Junggar shows a tendency to southward-younging in West Junggar (Zhang et al 2021a), which makes slab break-off model more feasible. This suggestion is also consistent with the uplift of the Junggar terrane remnant oceanic crust during its final development between 335 Ma and 333 Ma (Zhu et al 2015).…”

“…In the Early Carboniferous, the back-arc basin, which resulted from northwest-ward intra-oceanic subduction of the Junggar Ocean in the Zhongguai area between the Junggar complex basement and the Yili block (Zhang et al 2018), started to subduct with generation of arc-related I-type granites. Numerous volcano-clastic and tuffaceous materials from Carboniferous arc-related rocks were deposited quickly in this back-arc basin (Zhang et al 2021a). During subduction, the oceanic slab underwent break-off resulting in asthenosphere upwelling and the tectonic regime changed from compression to an extensional post-collisional setting in the early Late Carboniferous.…”

“…Both lateral accretion in active continental margins and vertical underplating at the crust-mantle interface contributed to continental crustal growth in CAOB (Jahn et al 2000;Windley et al 2007). Voluminous Late Palaeozoic granitoids with high and positive εNd(t) values were intruded throughout West Junggar (Jahn et al 2000;Chen & Jahn, 2004;Han et al 2006) and include a range of magmatic rocks including high-Mg andesites (e.g., sanukitoids/sanukitic rocks, adakites/adakitic rocks), A-and I-type granites and Nb-enriched diorites (Chen et al 2010;Yin et al 2010Yin et al , 2015aTang et al 2012aTang et al , 2012bXu et al 2013;Zhang et al 2018Zhang et al , 2021aZheng et al 2020). However, the tectono-magmatic setting of these Late Carboniferous to Permian magmatic rocks in West Junggar remains controversial with a range of tectonic settings and processes being proposed.…”

Detrital zircon U–Pb geochronology of the upper Carboniferous strata of Hala’alat Mountain, West Junggar: implications for provenance

“…A – convergent settings; B – collisional settings; C – extensional settings. Detrital zircon age data adapted from the (1) Xibekulas Formation (Zhang et al 2015); (2) Xibekulas Formation (An et al 2019); (3) Xibekulas Formation (Chen et al 2013); (4) Xibekulas Formation (Zhang et al 2021); (5) Baogutu Formation (Zhang et al 2021); (6) Telegula Formation (Zhang, P. et al 2018); (7) Telegula Formation (Choulet et al 2012 b ); (8) Telegula Formation (Zhang, P. et al 2018); and S8-4, S9-3 (this study). …”