Precambrian Hongqiyingzi Complex at the northern margin of the North China Craton: Its zircon U-Pb-Hf systematics, geochemistry and constraints on crustal evolution

The Precambrian Hongqiyingzi Complex (HQC) in the middle segment of the northern margin of the North China Craton (NCC) is a crucial magmatic intrusive complex offering insights into the early evolutionary history of the northern margin of the NCC. The HQC, exposed from Congli to Longhua towns in the northern Hebei Province, is mainly composed of Neoarchean quartz dioritic-tonalitic-granodioritic (DTG) gneisses and Paleoproterozoic granodiorite-monzogranite-syenogranite (GMS) intrusions. SHRIMP and LA-ICP-MS zircon dating results show that the DTG gneisses formed at 2546-2532 Ma, while the GMS intrusions were emplaced between 1870 and 1819 Ma. LA-MC-ICP-MS zircon Lu-Hf isotope analyses indicate that the Neoarchean DTG magmas were mainly derived from partial melting of juvenile crust, but the Paleoproterozoic GMS magmas originated from partial melting of the metamorphic basalts and greywackes from Neoarchean to Paleoproterozoic volcanic or related sedimentary materials. Lithological assemblages, chronological and geochemical data, petrogensis and geodynamic settings of the Neoarchean DTG and Paleoproterozoic GMS magmatism show that the HQC is most likely at the northernmost part of the Trans-North China orogen of the NCC. The Precambrian HQC thus recorded Neoarchean subduction-related arc magmatism and Paleoproterozoic post-collisional magmatism that were associated with subduction and collision at the northern margin of the NCC. These Precambrian geological units were intensively overprinted by Late Paleozoic calc-alkaline magmatism, which may be caused by southward subduction and collision of the Central Asian Orogenic Belt (CAOB) with the NCC.