Jurassic post‐collisional extension in the Songpan–Ganze Terrane, eastern Tibetan Plateau: Evidence from weakly peraluminous A‐type granites within the Zheduo–Gongga Massif

The Mesozoic–Cenozoic Zheduo–Gongga Massif, eastern Songpan–Ganze Terrane, can provide important clues for the crustal evolution in response to syn‐ and post‐orogeny. Here, we document petrological and geochemical characteristics of Early Jurassic granites (181.0 ± 2.2 Ma) within the massif along the Xianshuihe Fault in the eastern Tibetan Plateau. The granites have high contents of SiO2, Na2O + K2O, FeOT/MgO, 10,000 × Ga/Al, REE (except Eu) and HFSE (e.g., Nb, Ta, Zr, Hf), low CaO, TiO2, P2O5 and negative Eu, Sr, and Ba anomalies. Zircon REE shows a similar pattern with the whole‐rock REE. Our new data demonstrate weakly peraluminous A‐type affinity with A/CNK >1.0 and alkali‐calcic, ferroan features. Zircon saturation temperatures and geochemical features (e.g., high SiO2 and low MgO contents, high Rb/Ba and Rb/Sr ratios) indicate that the granites resulted from high‐temperature (>800°C) partial melting of Triassic flysch rocks in relatively shallow crust (800°C) partial melting of Triassic flysch rocks in relatively shallow crust (