Introduction

Abstract

AbstractIn the past decade, additional lines of evidence have indicated that the Meso- to Neoarchean was an important transitional period for the formation and evolution of continental crust as well as the corresponding geodynamic mechanisms, during which the compositions of the Archean granitoids and metavolcanic rocks changed significantly. In addition, the early Precambrian tectonic subdivision and late Neoarchean geodynamic setting of the North China Craton have long been controversial subjects. Systematic investigations of the geochemical features, temporal-spatial relationships, petrogenesis, and geodynamic processes of the various late Archean lithological assemblages in the North China Craton are crucial for resolving these scientific controversies. The Archean basement terranes of the Eastern Hebei-Western Liaoning Provinces in the northern Eastern Block preserve Paleo- to Neoarchean geological records and are dominated by late Neoarchean lithological assemblages. Recent studies have revealed that the Archean lithological assemblages in the Eastern Hebei-Western Liaoning Provinces display characteristic zonation and from northwest to southeast can be subdivided into the MORB-type tholeiite belt, oceanic arc tectonic belt, and K-rich granitoid belt, which are similar to the characteristics of the igneous lithological assemblages that have developed in modern convergent plate margins. In this dissertation, comprehensive investigations of the geology, petrology, tectonics, whole-rock geochemistry, and zircon in situ U–Pb-Hf–O isotopes were conducted on the porphyritic monzodioritic-quartz monzodioritic-granodioritic-monzogranitic (MQGM) gneisses and their tonalitic gneiss xenoliths, medium-grained monzogranite-syenogranites, taxitic dioritic-tonalitic gneisses, and metavolcanic rocks in the K-rich granitoid belt. This study aims to (1) determine the temporal-spatial relationships and petrogenesis of the various Archean lithological assemblages within the K-rich granitoid belt; (2) decipher the late Neoarchean crust-mantle interactions, tectonic setting, and geodynamic evolutionary model of the K-rich granitoid belt; and (3) provide further insight into the potassic enrichment processes of the late Archean continental crust.KeywordsNorth China CratonLate Neoarchean K-rich granitoid beltPetrogenesis and tectonic settingGeodynamic evolutionary modelLate Archean potassic enrichment processes