Zircon U–Pb ages and Lu–Hf isotopes of Paleoproterozoic metasedimentary rocks in the Korla Complex, NW China: Implications for metamorphic zircon formation and geological evolution of the Tarim Craton

New geochemical and combined zircon U–Pb and Lu–Hf isotopic data of orthogneisses in the northern Altyn Tagh, northern margin of the Tibetan plateau: Implication for Archean evolution of the Dunhuang Block and crust formation in NW China

“…The Dunhuang Block is commonly considered as an eastern part of the Tarim Craton (BGMRX, 1993;Lu et al, 2008b), but this viewpoint is challenged by recent geochronological studies on the Archean TTG gneisses from the Dunhuang Complex and Paleoproterozoic supracrustal rocks in the northern TC (Ge et al, 2013;Zhang et al, 2012cZhang et al, , 2013a. Zircon SHRIMP U-Pb dating indicated that the TTG gneisses formed at 2.56-2.50 Ga and underwent regional metamorphism at~2.5 Ga and another at 1.90-1.82 Ga (Zhang et al, 2013a).…”

“…Based on a comparison with the coeval magmatic-metamorphic events developed in the NCC, Zhang et al (2013a) proposed that the Dunhuang Block is the western extension of the Alxa terrane of the NCC. Ge et al (2013) compiled available geological and geochronological data in the northern and southern TC and suggested that two Paleoproterozoic collision orogenic belts existed in its northern and southern margins, respectively. Because of remarkable consistency with collisional orogenic belts in NCC, they suggested that the TC, including the Dunhuang Block, was correlative with the Alxa-Yinshan Block of the NCC, and these blocks became a coherent continent during the Neoarchean-early Paleoproterozoic (Ge et al, 2013).…”

Geochemistry of metamafic dykes from the Quanji massif: Petrogenesis and further evidence for oceanic subduction, Late Paleoproterozoic, NW China

“…For the TC, simple collision at 1.90-1.80 Ga was suggested by previous workers (e.g., Ge et al, 2013), but a two-stage subduction-accretion-collision model has also been proposed for the amalgamation of the TC with other continents which was coincident with global collisional events that led to the assembly of the Paleoproterozoic Columbia supercontinent based on the identified tectonothermal events ( Fig. 1; Chen et al, 2013b;Ge et al, 2013;Ma et al, 2013). Ma et al (2013) suggested subduction of oceanic crust southwards beneath the TC through a long time span of 2.5-1.90 Ga as the first stage, and collision of the TC with an unknown continent at 1.83-1.80 Ga as the second stage, while Liao et al (2014) suggested multiple subduction-collision along southern side of the TC during 2.2-1.90 Ga and at 1.83-1.80 Ga, respectively.…”

“…2.5 to 1.80 Ga Hassan Abdelslam Mustafa, Qinyan Wang, Nengsong Chen, Fanxi Liao, Min Sun andMeshaal Abdelgadir Salih 2 (Santosh et al, 2013, 2010, and the references therein; Santosh, 2010). For the TC, simple collision at 1.90-1.80 Ga was suggested by previous workers (e.g., Ge et al, 2013), but a two-stage subduction-accretion-collision model has also been proposed for the amalgamation of the TC with other continents which was coincident with global collisional events that led to the assembly of the Paleoproterozoic Columbia supercontinent based on the identified tectonothermal events ( Fig. 1; Chen et al, 2013b;Ge et al, 2013;Ma et al, 2013).…”

“…The Quanji massif (QM) has been considered as a cratonic fragment which has a similar complex history to that of the NCC and TC (Chen et al, 2013aGe et al, 2013;Gong et al, 2012;Lu et al, 2008;Lu, 2002). Based on new age data from metamorphic zircons and petrography, Chen et al (2013b) recognized two metamorphic events which can be linked to the subduction and/or collision, with the first stage at 1.95-1.90 Ga and the second at 1.82-1.80 Ga.…”