Detrital zircon U-Pb ages of the late Mesoproterozoic–Neoproterozoic Qiaotou formation in the Liao-Ji area of the North China Craton: implications for Rodinia reconstruction
The Qiaotou Formation comprises the late Mesoproterozoic to early Neoproterozoic strata in southern Jilin and Liaoning Provinces at the eastern margin of the North China Craton (NCC). The depositional age of the formation is 1.1–0.9 Ga, as constrained from the ages of the youngest detrital zircons and later mafic intrusions. U-Pb age dating of detrital zircons yielded age peaks at 1.16, 1.58, and 1.74 Ga, and a minor peak of 2.47 Ga. The late Neoarchaean to Palaeoproterozoic detrital zircons were derived from the ca. 2.5 Ga Longgang and Liaonan blocks, ca.1.9 Ga magmatic/metamorphic rocks and late Palaeoproterozoic extensional-related magmatic rocks in NCC. The abundance of Mesoproterozoic zircon grains is less easy to explain. The possible source may represent (i) possibly concealed/vanished Grenvillian magmatic rocks in NCC, or (ii) derivation from the Qinling Microcontinent or (iii) Fennoscandian shield, or (iv) São Francisco–Congo Craton.