Geochemistry and petrogenesis of 270 Ma Ni–Cu–(PGE) sulfide-bearing mafic intrusions in the Huangshan district, Eastern Xinjiang, Northwest China: implications for the tectonic evolution of the Central Asian orogenic belt

An Early Permian (ca. 280Ma) silicic igneous province in the Alxa Block, NW China: A magmatic flare-up triggered by a mantle-plume?

“…Early Permian igneous rocks are widely distributed in NW China (e.g., Qin et al, 2011;Su et al, 2011;Xia et al, 2012;Xu et al, 2013;Zou, 2013a, 2013b;Zhang et al, 2010), including the Tarim, Tianshan and CAOB, and constitute a large igneous province referred to as the Tarim or the Tianshan. A mantle plume has been invoked to explain the characteristics of these rocks (e.g., Qin et al, 2011;Su et al, 2011;Xu et al, 2013;Zhang et al, 2010;Zhou et al, 2004), e.g., widely distributed basaltic rocks (e.g., Zhang et al, 2010), extremely high magma temperatures estimated to be in the range of 1100-1600°C , and widely distributed mafic-ultramafic complexes (e.g., Qin et al, 2011). The Early Permian mantle plume was recently proposed to be situated closer to the Beishan Rift than the Eastern Tianshan and the western Tarim (Su et al, 2012).…”

“…280 Ma) igneous rocks with predominantly ultramafic-mafic rocks are widespread in the Tarim Craton and the Central Asian Orogenic Belt (CAOB) (e.g., Li et al, 2011;Wei et al, 2014;Xia et al, 2012;Xu et al, 2013;Yang et al, 2007Yang et al, , 2013Zhang et al, 2010;Zhou et al, 2004Zhou et al, , 2009, and correspond to the Tarim LIP (e.g., Qin et al, 2011;Su et al, 2011Su et al, , 2012. Recent dating of rocks on the Alxa Block, adjacent to the Tarim Craton and the CAOB, reveals that a large area of Early Permian (ca.…”

Sr, Nd and O isotopic characters of quartz syenite in the Weiya magmatic complex from eastern Tianshan in NW China: Melting of the thickened juvenile lower crust

“…Then, tectonic regime of eastern Tianshan change from compression to extension, resulting in emplacement of numerous postcollisional granitoids and mafic-and ultra-mafic rocks with ages ranging from around 300 Ma to 260 Ma in Central Tianshan , and in the Ooltag (Mao et al, 2002;Qin et al, 2002;Xu et al, 2003;Han et al, 2004;Zhou et al, 2004), Bogda (Gu et al, 2001b;Xia et al, 2007;Wang et al, 2009) and Kelameili-Harlik orogenic belts (Gu et al, 1999;Sun et al, 2007;Xiao et al, 2008). In accompany with these events, the Aqikkudug-Shaquanzi (ASF, Fig.…”

“…This belt seems to be one of the most important sites of juvenile crustal formation in the Phanerozoic . The juvenile nature is characterised by positive to around zero ε Nd (t) values and low initial Sr isotopic ratios of many Paleozoic granitoid plutons in the CAOB, such as those in Russian Transbaikalia (Wickham et al, 1996;Kovalenko et al, 2004), Kazakhstan (Heinhorst et al, 2000), northern Xinjiang (NW China, Han et al, 1997;Hu et al, 2000;Jahn et al, 2000;Jahn, 2002, 2004;Chen and Arakawa, 2005;Su et al, 2007;Zhao et al, 2008;, northern Inner Mongolia (N China, Chen et Shi et al, 1999;Zhou et al, 2004); KHF, Kumix-Hongliuhe Fault;ASF, Aqqikkudug-Shaquanzi Fault;KF, Kangguer Fault;Indosinian intrusive names: TH, Tianhu biotite granite (220 Ma, Li et al, 2005); WY, Weiya complex (246-233 Ma, Zhang et al, 2005a); NY, North Yamansu biotie granite (227.9 Ma, Lei et al, 2010). Insert (modified from Chung et al, 2004) Shu et al, 2004b).…”

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

“…The origin of these mafic rocks has been a matter of debate in three competing models: 1) mantle plume or crustal rifting (Che and Liu, 1996;Xia et al, 2004bXia et al, , 2008, which predicts a dominant role for an upwelling deep-seated mantle plume impinging on the lithosphere (Xia et al, 2004b(Xia et al, , 2008; 2) an island arc model, which suggests a subduction of the Paleo-Tianshan Oceanic Plate Zhou et al, 2004;Zhu et al, 2005Zhu et al, , 2009; or 3) a post-collisional model that invokes slab break-off and subsequent asthenospheric upwelling after the collision between the Junggar plate and the Yili terrane (e.g., Han et al, 2010;Yuan et al, 2010). In this study, we determined plagioclase 40 Ar/ 39 Ar ages and undertook whole rock geochemical and Sr-Nd isotope analyses, electron microprobe analyses of clinopyroxene major element compositions and LA-ICPMS clinopyroxene trace element analyses for the Luotuogou gabbros north of Baluntai town in the Central Tianshan Terrane (Fig.…”