“…Some researchers have suggested an early Carboniferous timing for the final closure of the Paleo-Junggar Ocean (Gao et al, 1998), whereas others argued for late Carboniferous Zhang et al, 2009a;Chen et al, 2010) or Permian (Long et al, 2006;Xiao et al, 2008;Geng et al, 2009;Tang et al, 2010a). Previous studies were mainly concentrated on the voluminous Carboniferous granitoids (Han et al, 1997;Chen and Jahn, 2004;Su et al, 2007;Geng et al, 2009;Yang et al, 2011a), and proposed several tectonic models including ridge subduction (Geng et al, 2009), slab break-off (Niu et al, 2006;Yuan et al, 2010) and the detachment of an orogenic root zone . As the granitic magmas are produced by partial melting of crustal materials, and may give ambiguous tectonic implications (Wu et al, 2007), these models need to be augmented with other petrological and geochemical data.…”