Reactivation of the Archean lower crust: Implications for zircon geochronology, elemental and Sr–Nd–Hf isotopic geochemistry of late Mesozoic granitoids from northwestern Jiaodong Terrane, the North China Craton
MetadataShow full item record
The late Mesozoic granitoids widely distributed in the northwestern Jiaodong Terrane are important markers of cratonic destruction and lithospheric thinning of the eastern North China Craton (NCC). Here we investigate the Late Jurassic Linglong and Luanjiahe granites and report zircon U–Pb emplacement ages of 157–159 Ma. These rocks also contain abundant late Archean, Paleoproterozoic, Neoproterozoic, early Paleozoic and Triassic inherited zircons, suggesting the involvement of continental crustal materials from both the NCC and Yangtze Craton in magma tectonics. The rocks investigated in this study show high Na2O + K2O and low MgO and are peraluminous, with enrichment in LREEs and LILEs (Rb, Ba, U, and Sr) and depletion in HFSEs (Nb, Ta, P, and Ti). They also display low εHf(t) values and high Sr/Y ratios, comparable to adakitic rocks, suggesting that the Linglong and Luanjiahe granitoids formed under relatively high pressure conditions and were likely derived from the partial melting of the thickened lower crust of the NCC. The Guojialing granodiorites were emplaced in the early Cretaceous (129 Ma), and also contain abundant late Archean and Paleoproterozoic inherited zircons. The rocks possess high CaO, TFe2O3 and MgO, and are metaluminous, with enrichment in LREEs and LILEs and depletion in HFSEs. They are also characterized by high Sr/Y ratios, and have higher εNd(t) and εHf(t) values than the Late Jurassic granitoids, suggesting the involvement of mantle components in the magmatic source. We correlate the magma tectonics with the processes accompanying the subduction of the Pacific Plate beneath the NCC and the associated asthenospheric upwelling.
Showing items related by title, author, creator and subject.
De Waele, Bert (2004)The Irumide belt is an elongate crustal province characterised by Mesoproterozoic tectonism and magmatism that stretches over a distance of approximately 900 kilometers from central Zambia to the Zambia-Tanzania border ...
Synchronous crustal growth and reworking recorded in late Paleoproterozoic granitoids in the northern Tarim craton: In situ zircon U-Pb-Hf-O isotopic and geochemical constraints and tectonic implicationsGe, R.; Zhu, W.; Wilde, Simon; He, J.; Cui, X. (2015)Identifying the relative contribution of various crustal and mantle materials in the source of granitoids is crucial for the study of granite petrogenesis and crustal growth. Extensive and diverse late Paleoproterozoic ...
Thomas, R.; Spencer, Christopher; Bushi, A.; Baglow, N.; Boniface, N.; de Kock, G.; Horstwood, M.; Hollick, L.; Jacobs, J.; Kajara, S.; Kamihanda, G.; Key, R.; Maganga, Z.; Mbawala, F.; McCourt, W.; Momburi, P.; Moses, F.; Mruma, A.; Myambilwa, Y.; Roberts, N.; Saidi, H.; Nyanda, P.; Nyoka, K.; Millar, I. (2016)Geological mapping and zircon U-Pb/Hf isotope data from 35 samples from the central Tanzania Craton and surrounding orogenic belts to the south and east allow a revised model of Precambrian crustal evolution of this part ...