Abstract Knowledge of the history of the Earth’s continents and the genesis of mineral deposits is poorly understood on a crustal-scale. This contribution combines geological and zircon Hf-isotopic data collected… Click to show full abstract
Abstract Knowledge of the history of the Earth’s continents and the genesis of mineral deposits is poorly understood on a crustal-scale. This contribution combines geological and zircon Hf-isotopic data collected from igneous rocks associated with mineralisation to gain a better understanding of the nature of the growth of, and mineral genesis in the North China Craton. The new zircon U–Pb dates reported here are 2587 ± 62 Ma for syenogranite at Zanhuang in the northeast part of craton, 2552 ± 24 Ma for trondhjemitic gneiss and 2554 ± 29 Ma for metadiorite at Dengfeng in the eastern and central part of, and 2820 ± 6 and 2821 ± 32 Ma for tonalite at Lushan in the southeast part of the craton. Lu-Hf isotopic data collected from granitic rocks for this study yield eHf(t) values and Hf crustal model ages (TDMc) of 3–5.8 and 2580–2600 Ma for the syenogranite at Zanhuang, 1.9–7.4 and 2550–2580 Ma for trondhjemitic gneiss and metadiorite at Dengfeng, and 0.5–5.2 and 3120–2840 Ma for tonalite at Lushan. Six major magmatic events have been recognised throughout the region. The crustal growth and reworking of the craton includes Eo- to Mesoarchean, early Neoarchean, and Paleoproterozoic events. The consistency in the evolution of Neoarchean magmatism coupled with zircon Hf isotope systematics indicate that similar crustal growth and reworking were in action in the Eastern, Trans-North China, and Western blocks. The crust architecture indicated by Hf isotopic mapping of the North China Craton constrains the distribution of mineral deposits. The BIF-hosted Fe deposits are spatially related to juvenile or reworked crustal domains, with groups of deposits located internal to and at the margins of Archean terranes, and orogenic Au deposits are spatially associated with juvenile crustal domains.
               
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