Tectono-Stratigraphic framework and Palaeozoic evolution of the Chinese South Tianshan

Provenance of late Paleozoic strata in the Yili Basin: Implications for tectonic evolution of the South Tianshan orogenic belt

“…The continental deposits at the base of the Dongtujinhe Formation at Tekesi are replaced by shallow-marine deposits. This sedimentary variation is consistent with that in local areas in the South Tianshan belt, where the contemporaneous stratigraphic record shows a change from shallow-marine limestones to deeper-marine, thinly bedded marls interbedded with calcareous sandstones (Alexeiev et al, 2015). These provenance and stratigraphic records suggest that the continent-continent collision may have been discontinuous, consistent with the multiphased deformation in the South Tianshan belt during the late Carboniferous-Early Permian (Alexeiev et al, 2015).…”

“…310 Ma. This age is consistent with the youngest ages of tectonic exhumation of South Tianshan (U)HP metamorphic rocks (Hegner et al, 2010;Su et al, 2010;Xia et al, 2016) and the age of deformation in the ophiolite mélanges and metamorphic belt (Alexeiev et al, 2015). The unconformity at the base of the Dongtujinhe Formation possibly records deformation of the overriding plate during the exhumation of (U)HP metamorphic rocks and the terminal stages of oceanic subduction Soldner et al, 2016).…”

Detrital zircons from Neoproterozoic sedimentary rocks in the Yili Block: Constraints on the affinity of microcontinents in the southern Central Asian Orogenic Belt

“…This ocean is considered to have closed in the late Carboniferous, based on the 316 Ma Sikeshu pluton intruding the ophiolite and the occurrence of postcollisional stitching intrusions (310-280 Ma) (Wang et al, 2006;Han et al, 2010). Likewise, the ST is mainly composed of Paleozoic clastic and volcano-sedimentary rocks (XBGMR, 1993;Chen et al, 1999a;Biske and Seltmann, 2010;Alexeiev et al, 2015). High pressure-low temperature (HP-LT) metamorphic assemblages (454-302 Ma) with relicts of blueschist, eclogite, ophiolite and meta-sedimentary rocks occur as tectonic lenses within the Paleozoic sedimentary strata (Gao et al, 1998;Zhang et al, 2003;Klemd et al, 2005;Gao et al, 2011;Klemd et al, 2011).…”

“…The NT and ST are Paleozoic accretionary terranes Xiao et al, 2013;Alexeiev et al, 2015). The NT consists of Devonian-Carboniferous volcanic rocks, volcaniclastic rocks and turbidites (Wang et al, 2006).…”

“…The CAOB is a complex collage of ancient microcontinents, island arcs, seamounts and oceanic plateaux (Sengör and Natal'in, 1996;Jahn et al, 2000Jahn et al, , 2004Xiao et al, 2004;Windley et al, 2007;Eizenhöfer et al, 2014;Han et al, 2015;Eizenhöfer et al, 2015a,b;Han et al, 2016a,b). Microcontinents and continental fragments are considered to have been incorporated into the CAOB during its accretion (Windley et al, 2007;Gao et al, 2011;Kröner et al, 2012;Alexeiev et al, 2015;Zhang et al, 2015aZhang et al, ,b,c, 2016. However, their origins are still controversial, with some researchers assuming that some microcontinents within the CAOB had a Gondwana derivation and were then accreted onto the southern margin of the Siberian Craton (Zonenshain et al, 1990;Buslov et al, 2001;Dobretsov et al, 2003;Kheraskova et al, 2003;Laurent-Charvet et al, 2003;Xiao et al, 2010).…”