Neoarchean–Paleoproterozoic crustal growth and tectonic evolution of the Trans-North China Orogen, North China Craton: evidence from granite–greenstone successions in the Dengfeng Complex

Granite–greenstone successions and associated tonalite–trondhjemite–granodiorite (TTG) suites constitute dominant components of Precambrian cratons. Here, we present petrology, geochemistry, zircon U–Pb geochronology, and Lu–Hf isotopes on monzonite, granodiorite, granite, and amphibolite from the Dengfeng Complex in the southern part of the North China Craton (NCC). Zircon U–Pb data yield weighted mean 207Pb/206Pb ages of 2498 ± 6 Ma for monzonite, 2481 ± 16 Ma for granodiorite, and 2475 ± 21 Ma for granite. Lu–Hf isotope systematics show εHf(t) values ranging from 1.3 to 6.7 and crustal model ages (TDMC\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_{{{\text{DM}}}}^{{\text{C}}}$$\end{document}) in the range of 2584–2934 Ma for the rocks. The monzonite, granodiorite, and granite show moderate total rare-earth element (REE) contents, enrichment in light REEs (LREE) and depletion in heavy REEs (HREE), negative Nb, Ta, and Ti anomalies, high Al2O3, Sr/Y, and (La/Yb)N ratios, with low Cr and Ni, indicating that the magma was possibly sourced from partial melting of the lower crust. The geochemical features of amphibolites are characterized by low SiO2, Na2O, K2O, Sr/Y, (La/Yb)N and high FeO, low total REEs values, limited LREE/HREE fractionation, and absence of obvious Ce anomaly, showing similarity to island arc magmatic rocks. Our results are consistent with the model of subduction and arc–continent collision in the Trans-North China Orogen during the Neoarchean to Paleoproterozoic.