Nature of the latest Paleoproterozoic tectono-magmatic event in central North China and its tectonic genetic model

Abstract：The latest Paleoproterozoic Period represents one of the most important transition stages of the evolution of the North China craton, but its relevant tectonothermal episodes and tectonic framework are rarely documented in detail. In this paper, the tectonic evolution and genetic model are discussed based on the regional tectonic analysis, combined with the latest isotopic age dating. The NW-trending Taihang-Hengshan mafic dike swarms (1.80-1.77 Ga) correspond to failed arms of the Yanliao and Taihang aulacogens, which formed an asymmetric aulacogen system with triple arms. The relevant anorogenic magmatism consists (in order of time) of granite and pegmatite intrusion (1.85-1.80 Ga), injection of basic dike swarms (1.80-1.77Ga), anorthosite,alkaline granite and rapakivi granite intrusion (1.71-1.70 Ga) and volcanic eruption (1.68 Ga). As indicated by the regional correlation of the underlying basement complexes and isotopic age dating, large-scale domal uplift took place in the Yanliao-Taihang area at ~1.80 Ga, with an uplift diameter up to 1000 km. The core area of the domal uplift is located at the center of the Yaoliao-Taihang aulacogen system. The uplift of the basement coincided with the supracrustal extension structures and anorogenic magmatism in time and space, which supports the mantle plume model for a rational interpretation of the above-mentioned regional uplift and extensional break-up event in the latest Paleoproterozoic episodes of the North China carton.