Magmatic events recorded in granitic gneisses from the Hatu area, eastern East Kunlun Orogen: Response to the assembly of Rodinia

Abstract

A suite of granitic gneisses has been identified in the Hatu area, eastern segment of the East Kunlun Orogen. Zircon U–Pb dating of granitic gneisses indicates magmatic crystallization at 895.4 ± 9.3 Ma. However, some zircons yield a metamorphic age of 433.8 ± 6.2 Ma. When taken together, these data reveal that the Early Neoproterozoic granites experienced Early Paleozoic metamorphism. The granitic gneisses are characterized by high contents of SiO2, Al2O3, and K2O + Na2O and low concentrations of TiO2, MnO, and CaO. The petrochemical character (average A/CNK = 1.09 and average A/NK = 1.42) and the mineral assemblages suggest that the granites are of S type and peraluminous. The chondrite‐normalized rare earth element patterns of the samples show enrichment of light rare earth elements ((La/Yb)N = 13.84) and moderate negative Eu anomalies (δEu = 0.60). The primitive‐mantle‐normalized trace element diagrams show an enrichment of Rb and Th and a depletion of Ta, Nb, Sr, P, and Ti. The granitic gneisses have features of crust‐derived and typical continent–continent syn‐collisional granites. All the above characteristics suggest that the Paleoproterozoic Baishahe Formation probably served as the source rocks and that the granitic gneisses were generated by partial melting of the metasedimentary material related to crustal thickening. They also reveal a collision between the micro‐block in the Early Neoproterozoic in response to the assembly of the supercontinent Rodinia in East Kunlun.

Early Paleoproterozoic magmatism in the Yangtze Block: Evidence from zircon U-Pb ages, Sr-Nd-Hf isotopes and geochemistry of ca. 2.3 Ga and 2.1 Ga granitic rocks in the Phan Si Pan Complex, north Vietnam

“…The relatively high-T and high-P conditions for formation of the 2.30 Ga quartz monzonites are similar to granite formed by crustal thickening in zones of collisional orogenesis (Pearce et al, 1984;Barbarin, 1996Barbarin, , 1999Chen et al, 2017). The most effective thickening process would be tectonic shortening due to the convergence of plates, such as arc-continent or continent-continent collision (Hsu and Sibuet, 1995;Giese et al, 1999).…”

Metamorphic evolution and geological significance of Early Palaeozoic high‐pressure granulites from the East Kunlun (NW China)

“…(b) Histograms of zircon ages of the metamorphic (lower part) and intrusive (upper part) rocks. Metamorphic age data include eclogites (Du, 2018; Jia et al, 2014; Meng, Zhang, & Cui, 2013; Qi et al, 2014; Qi, Fan, et al, 2016; Song et al, 2018; Xiong & Ma, 2016), granulites (Bi et al, 2021; Li et al, 2006; Wang, Zhao, et al, 2022; Zhang et al, 2003; this study), amphibolites (Chen et al, 2008; Guo et al, 2018; Li et al, 2022; Wang, 2014), schists (Bi et al, 2020; Song et al, 2018) and gneisses (Bi et al, 2021; Chen et al, 2008, 2017; Gao et al, 2023; He et al, 2016; Liu et al, 2016; Meng et al, 2017; Meng, Cui, et al, 2013; Tang et al, 2022). The metamorphic rocks as a whole show three peak values (410 Ma, 430 Ma, and 508 Ma) on the probability density curve.…”

Central China Orogen along the Silk Road (Part I): Tectono‐thermal evolution and its links

“…In the Kunlun Orogen and Tibet (comprising seven papers), the study by Chen et al () examined magmatic events recorded in granite gneisses in East Kunlun Orogen. In the paper by He et al (), fractal characteristics of fault systems were applied to Qimantage orefield in East Kunlun.…”