Petrogenesis of Early-Permian sanukitoids from West Junggar, Northwest China: Implications for Late Paleozoic crustal growth in Central Asia

Structural evolution and late Carboniferous magmatism of the Zhongguai arc in the western Junggar Basin, Northwest China: implications for tectonic evolution of the Junggar Ocean

“…Subsequently the amalgamated southern West Junggar terrane and WJB were controlled by northwestward subduction of the Junggar Ocean (Figure 13b). Recent studies suggests that the ridge subductionrelated thermal regime may have persisted into the early Permian and produced 299-284 Ma magnesian dikes (Yin et al 2013(Yin et al , 2015. The occurrence of the middle Permian terrestrial sediments and thrusting reactivation in the Zhongguai arc (Figures 3 and 12) are possibly indicative of the final welding of the southern West Junggar-WJB terrane and other units of the Junggar basement (Figure 13c), followed by Mesozoic tilting due to episodic modification ( Figure 12).…”

“…Continued subduction of the Junggar Ocean transported the spreading ridge to the subduction zone, while partial melting of a slab edge close to a subducting spreading ridge may be responsible for the formation of the 327-325 Ma adakitic rocks in the Zhongguai arc (Li et al 2014a). As a slab window opened (Figure 13b), unusually high temperatures provided by the upwelling asthenosphere caused widespread melting of variable crust or mantle sources in the late Carboniferous, as indicated by the coeval occurrence of tholeiitic, magnesian, and adakitic magma, and the alkaline rocks in both the KLD and KRD (Geng et al 2009;Liu et al 2009;Tang et al 2010;Zhang et al 2011a;Ma et al 2012;Li et al 2015b;Yin et al 2015;this study). Given that ridge subduction-related magmatisms affected the entire area from the southern West Junggar terrane to Zhongguai arc at 309-302 Ma (Figure 12), and that there is an absence of coeval arc volcanic rocks resulting from subduction of the Darbut Ocean at the northern margin of the southern West Junggar terrane or in the Chingiz arc terrane, we consider that the YTD-KLD-KRD accretionary system had possibly been docked to the Zhongguai arc through a continuous, single southeastward accretion (Choulet et al 2012) prior to the emplacement of these ridge subduction-related magmatisms and began to receive the proximal arc sediments from the Zhongguai arc (Tao et al 2013).…”

Late Silurian–early Devonian adakitic granodiorite, A-type and I-type granites in NW Junggar, NW China: Partial melting of mafic lower crust and implications for slab roll-back

“…Recently, many authors proposed that they may be related to ridge subduction during the late Carboniferous-early Permian Tang et al, 2010Tang et al, , 2012Xiao et al, 2014a;Yin et al, 2010Yin et al, , 2013bYin et al, , 2015bZhang et al, 2011a,b). In the Xiemisitai and Saier mountains there are widespread late Silurian-early Devonian volcanic rocks and their sub-volcanic equivalents (Shen et al, 2012;Yang et al, 2014b).…”

Identifying late Carboniferous sanukitoids in Hala’alate Mountain, Northwest China: new constraint on the closing time of remnant ocean basin in West Junggar

“…Identification of sanukitoids is crucial for understanding the dynamic evolution of a palaeosubduction system and provides important constraints on the fate of subducted slabs (Tatsumi 1981(Tatsumi , 1982Ishizaka 1981, 1982;Kamei et al 2004;Martin et al 2005). Therefore, sanukitoids have attracted considerable attention from petrologists and geochemists (Tatsumi 1981(Tatsumi , 1982Ishizaka 1981, 1982;Shirey and Hanson 1984;Tatsumi et al 2003;Kamei et al 2004;Zhang et al 2004Zhang et al , 2005Wang et al 2011;Yin et al 2010Yin et al , 2012Yin et al , 2015aMa et al 2012;Tang et al 2012a;Sun et al 2015).…”

“…Although a few intrusive sanukitoid rocks have been documented in West Junggar, northwest China (Yin et al 2010(Yin et al , 2012(Yin et al , 2015aMa et al 2012;Tang et al 2012a), no volcanic sanukitoid rocks are reported.…”