Convergence of two ancient continental nuclei induced by late Neoarchean multiple subduction systems

Abstract Many global cratons contain lithospheric nuclei composed of ancient continental materials (pre–3.0 Ga), whereas the geodynamic processes and pathways responsible for their growth into mature cratons remain subjects of significant debate. Pervasive Neoarchean mantle-derived magmatism along the margins of ancient continental nuclei serves as critical geological archives for deciphering these issues. Here, we focus on the late Neoarchean mantle-derived volcanic rocks of the Northern Liaoning terrane (NLT), which is located between the Anshan-Benxi continental nucleus (ABCN) and Baishan continental nucleus (BSCN) in the northeastern North China Craton (NCC). Regional investigations in structural geology, lithological assemblages, chronology, geochemistry, and isotopic characteristics suggest that the Archean crystalline basement of the NLT can be divided into three independent tectonic domains: Waitoushan–Weiziyu–Jiubing domain in the southwest, Fushun–Tangtu–Xinbin (FTX) domain in the central, and Hongtoushan–Qingyuan–Xiajiabao (HQX) domain in the northeast. The HQX domain was likely separated from the adjacent Southern Jilin terrane (SJT) through the sinistral displacement of the Mishan-Dunhua fault zone. Detailed studies of geochemical classification and petrogenesis of mantle-derived volcanic rocks, and their tectonic implications, indicate that the NLT and SJT preserve a continuous record of a ca. 2.58–2.50 Ga continental margin arc system along the ABCN, involving processes ranging from subduction initiation to deep subduction, a ca. 2.60–2.50 Ga intra-oceanic arc system, together with a ca. 2.58–2.51 Ga continental margin arc system proximal to the BSCN. The lateral plate motions induced by multiple subduction systems would lead to convergence of the ABCN and BSCN, and subsequent ca. 2.53–2.47 Ga arc-arc and/or arc-continent collisions, finally forming a unified continental block of the northeastern NCC. Our results provide direct evidence for the operation of plate tectonics during the late Neoarchean, offering new insights into the transformation from ancient continental nuclei to mature Archean cratons.