Double-layer structure of the crust beneath the Zhongdian arc, SW China: U–Pb geochronology and Hf isotope evidence

U–Pb ages and Hf isotopes of zircons in Late Triassic and Cretaceous intrusive rocks from the Zhongdian arc, SW China, are used to decipher the tectonic, magmatic, and metallogenic processes that occurred during this period. New U–Pb dating of zircons from Late Triassic porphyries yielded ages of ca. 216 Ma and εHf(t) values of −2.1 to +6.1. Combined with previous results, the data indicate that these Late Triassic rocks were most likely derived...