Available online at www.sciencedirect.com Precambrian Research 163 (2008) 279–306 A comparison of U–Pb and Hf isotopic compositions of detrital zircons from the North and South Liaohe Groups: Constraints on the evolution of the Jiao-Liao-Ji Belt, North China Craton Yan Luo a,b,1 , Min Sun a,∗ , Guochun Zhao a , Sanzhong Li c , John C. Ayers b , Xiaoping Xia a , Jiheng Zhang d a Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong b Department of Earth and Environmental Sciences, Vanderbilt University, VU Station B, #351805, 2301 Vanderbilt Place, Nashville, TN 37235-1805, USA c Department of Marine Geology, Ocean University of China, Qingdao 266003, China d Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China Received 6 October 2007; received in revised form 9 January 2008; accepted 28 January 2008 Abstract The Jiao-Liao-Ji orogenic belt is one of the important Paleoproterozoic mobile belts in the North China Craton (NCC) and its central segment consists of the North and South Liaohe Groups and the Liaoji Granitoids. The North and South Liaohe Groups consist of sedimentary and volcanic successions metamorphosed from greenschist to lower amphibolite facies, and the Liaoji granitoids are divisible into 2.2–2.1 Ga (pre-tectonic) monzogranitic gneisses and 1.88–1.85 Ga (post-tectonic) porphyritic monzogranites and alkaline syenites. Combined with cathodoluminescence (CL) imaging, we report LA-ICP-MS (laser ablation inductively coupled plasma mass spectrometry) U–Pb and Hf isotopic data for detrital zircons from the North and South Liaohe Groups. Zircons grains from both groups have igneous zircon cores that yielded two U–Pb age populations at 2.0–2.2 Ga (major) and ∼2.5 Ga (minor), indicating that their provenances were similarly dominated by Paleoproterozoic Liaoji Granitoids and late Archean basement rocks. Some structureless zircon rims in both groups yield concordant or upper intercept ages ∼1.9 Ga, interpreted as the peak metamorphic age of the two groups. These results suggest that both groups were deposited in the period 2.0–1.9 Ga, shortly after the emplacement of the Liaoji Granitoids. Moreover, zircons from both groups have similar Hf model age peaks (T C DM peaks at 2.66–2.75 Ga and 2.80–3.00 Ga) and εHf values (-5 to +9 and -7 to +5). Based on these striking similarities, we propose that the protoliths of the North and South Groups may have formed simultaneously, and that the basement rocks underneath the two groups belong to the same Archean continental block rather than two different blocks as previously considered. The Archean basement underwent Paleoproterozoic rifting, accompanied by the emplacement of the Liaoji granitoids at 2.2–2.1 Ga and the deposition of the North and South Liaohe Groups at 2.1–1.9 Ga, and the rift was subsequently closed by ∼1.9 Ga. © 2008 Elsevier B.V. All rights reserved. Keywords: Detrital zircon; LA-ICP-MS; U–Pb age; Hf isotope; Liaohe Group; North China Craton 1. Introduction Clastic sediments preserve the history of the exposed con- tinental crust at the time of their deposition (e.g. Taylor and McLennan, 1985, 1995; McLennan, 2001; Rudnick and Gao, ∗ Corresponding author. Fax: +1 852 25176912. E-mail addresses: minsun@hkucc.hku.hk, yxl39@psu.edu (M. Sun). 1 Present address: Department of Geosciences, Pennsylvania State University, University Park, PA 16802, USA. 2003). Well-preserved sedimentary sequences in Precambrian basement are rare, albeit crucial for deciphering early continental evolution (Andersen et al., 2004). In particular, Palaeoprotero- zoic volcano-sedimentary sequences are intriguing, because they provide insights into geodynamic, magmatic, sedimento- logical and metallogenic processes in the Paleoproterozoic, a critical time to understand the development of tectonic regimes. During this time, modern plate tectonics may have played an important role and significant base and precious metal deposits were also formed (Pirajno et al., 1998). This is the case in the North China Craton (Chinese portion of the Sino-Korean 0301-9268/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.precamres.2008.01.002