Age of the Zhongtiaoshan dyke swarm: Constraints on the nature of the 1.8 Ga large igneous province event in North China

A large number of weakly metamorphosed or unmetamorphosed intermediate-basic dykes are developed in the Zhongtiao Mountain area. They are large-scale dykes in the early Mesoproterozoic of the North China Craton (1.80~1.76 Ga). An important component of the dyke swarm, accurately determining its emplacement age will have a profound impact on the fine spatiotemporal distribution of the dyke swarm, and understanding the geomorphology of the North China Craton during this period. The process of spherical dynamics is of great significance. This study carried out baddeleyite ion probe dating on a nearly east-west rock wall near Wangzhuang Village, Yongji, and obtained Its 207Pb/206Pb age is 1799±4 Ma (n=20, MSWD=2.2). This age effectively fills the gap in the age of the dyke group in key areas, and provides important insights into the The formation age and spatial distribution of the Xiong'er (1800~1785 Ma) and Taihang (1770~1760 Ma) complex dykes of two different generations in the Early Proterozoic complex dykes. The characteristics provide important clues. At the same time, the 1799 Ma intermediate-basic dyke in Zhongtiao Mountain is also the earliest unmetamorphic dyke in the North China Craton reported so far. As the Xiong'er It is the possible beginning of magmatic activity in this period. It not only provides an important reference for defining the age of the bottom of the Xiong'er Group volcanic rock system, but also provides a reference for the large igneous province (or dyke group). The terrane correlation and supercontinent reconstruction of the landmarks provide a new basis. Based on the geometric, chronological and geochemical characteristics of the dyke group, this paper supports that Xiong'er, The Taihang dyke group is the product of mantle plumes acting on the lithosphere of the moving North China Craton continental plate at different stages.