Detrital zircon U-Pb geochronology and Lu-Hf isotopic analysis of the Neoproterozoic Penglai Group and their comparisons with coeval sedimentary strata of the southeastern North China Craton: provenance, tectonic affinity and implications

The results of U-Pb dating and Hf isotopic analyses of detrital zircons from the Penglai Group in the Jiaobei terrane of the North China Craton (NCC) gave age populations of 1300-1000, 1500-1300, 1700-1500, 1800-1700 and >1800 Ma. The age spectra, variations in U and Th contents, Th/U ratios and Hf isotopic compositions of the detrital zircons of the Penglai Group are identical to those of the Tonian strata of the southeastern NCC. The Penglai Group rocks also have a similar litho- and biostratigraphy and tectonic setting to these Tonian strata, suggesting that the Penglai Group has a tectonic affinity with the NCC and was deposited during the Tonian. The detrital zircon age populations of the Penglai Group are consistent with the multiple magmatic and thermal metamorphic events in the NCC, especially the 1300-1000 Ma intermediate-acid and/or acid igneous rocks of the Korean Peninsula, and we therefore propose that the Penglai Group is mainly sourced from the NCC. The detrital zircon populations of 1300-1000, 1500-1300, 1700-1500 and 1800-1700 Ma show both positive and negative epsilon(Hf(t)) values, which, combined with late Paleoproterozoic-Neoproterozoic basic magmatism represented by large volumes of diabase sills in the NCC, suggests that the NCC experienced strong crust-mantle interactions that might have triggered continuous, multi-stage rifting in the NCC during the late Paleoproterozoic (1.8 Ga)-Neoproterozoic.