Metasomatized lithosphere–asthenosphere interaction during slab roll-back: Evidence from Late Carboniferous gabbros in the Luotuogou area, Central Tianshan

Petrogenesis of a Late Carboniferous mafic dike–granitoid association in the western Tianshan: Response to the geodynamics of oceanic subduction

“…(b) Tectonic discrimination plot for granites (Pearce et al, 1984) and western Tianshan Early Permian leucogranite dikes are shown for comparison . Tang et al (2010Tang et al ( , 2012a formed at an arc setting related to oceanic subduction. The most likely tectonic model accounting for the genesis of these rocks involves an extensional environment in the western Tianshan during the Late Carboniferous as a tectonic response to the roll-back of subducted Junggar oceanic lithosphere, which could accounts for the "flare-up" of Late Carboniferous magmatism.…”

“…7c-d, 12b) . In addition, the other Late Carboniferous basaltic rocks from the western Tianshan all show typical island arc type geochemical characteristics, suggesting that their origin was related to oceanic subduction (Tang et al, 2012a). Furthermore, Carboniferous ophiolites have recently been identified in the area, e.g., the 344 ± 3 Ma Bayingou ophiolite in the western Tianshan .…”

“…The resulting magmatic rocks ranged from basaltic to rhyolitic in composition similar to the Late Devonian to Early Carboniferous magmatic rocks. At the same time, many Late Carboniferous mafic rocks were emplaced in the western Tianshan, e.g., the Luotuogou gabbroic pluton (312 Ma, Tang et al, 2012a) and Haladala gabbroic pluton (306 Ma, Zhu et al, 2010). Recent studies suggested that these Late Carboniferous mafic rocks were derived from a depleted mantle source containing an asthenospheric component.…”

Petrology and geochemistry of late Carboniferous hornblende gabbro from the Awulale Mountains, western Tianshan (NW China): Implication for an arc–nascent back-arc environment

“…From Early Silurian to Early Carboniferous, the South Tianshan Ocean was subducted beneath the YCTB (Gao et al, 1998;Qian et al, 2009;Long et al, 2011). The middle Silurian Jingbulake mafic-ultramafic intrusion and the late Carboniferous Luotuogou gabbro and Bulusitai gabbro from the Central Tianshan were both thought to have formed during the northward subduction of the South Tianshan Ocean (Yang and Zhou, 2009;Tang et al, 2012;Tian et al, 2014). The Sr-Nd isotopic range of these intrusions is overlapped with the Awulale Carboniferous basalt on our studied samples (Fig.…”

Late Devonian–early Permian accretionary orogenesis along the North Tianshan in the southern Central Asian Orogenic Belt

“…Other ages from the Issyk Kul arc vary mainly between 1085 ± 11 and 1373 ± 5 Ma, among which the oldest is 2791 ± 24 Ma from the Koyan-disai River in southern Kazakhstan Degtyarev 2011;Kröner et al 2013). Palaeozoic subduction-related magmatic rocks are widespread throughout the whole Tianshan arc collage (Wang et al 2007bKonopelko et al 2008;Kröner et al 2008;Li et al 2008;Yang and Zhou 2009;Zhu et al 2009;Glorie et al 2010;Tang et al 2010Tang et al , 2012Zhang et al 2010Zhang et al , 2012aZhang et al , 2012bDe Grave et al 2011Degtyarev 2011;Dong et al 2011;Long et al 2011;Yang et al 2012).…”