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• The granodiorites and monzonitic diorites were originated from slab melts and slab melts-metasomatized mantle source, respectively. • The alkali feldspar granites were produced by partial melting of a crustal source in an extension background. • The gabrros were generated by partial melting of mantle wedge metasomatized by slab-derived fluids. • A slab window was likely happened at 2.46–2.44 Ga in the south margin of the Yinshan Block. The earliest Paleoproterozoic magmatic rocks have recorded the transition from the Neoarchean cratonization of the NCC to its post-Archean tectonic evolution, which will provide insight into the onset of the modern-style subduction. This study focuses on the early Paleoproterozoic granodiorite, monzonitic diorite, alkali feldspar granite and gabbro in the Guyang area to decipher the early Paleoproterozoic tectonic evolution of the Yinshan Block. Zircon U–Pb dating indicates that these rocks were emplaced at ca 2.46 – 2.41 Ga. The ∼ 2.46 Ga granodiorite samples have high Sr contents, low Y and Yb contents with high Sr/Y ratios, similar to the characteristics of adakitic rocks. Based on their high Mg# values, Na 2 O/K 2 O ratios, Cr, Co and Ni concentrations, and positive ε Nd (t) values, we propose that the granodiorite was likely produced by partial melting of subducting oceanic slab. The contemporary monzonitic diorite samples are characterized by high Nb concentration, which are similar to those of Nb-enriched basalt/andesite. The monzonitic diorite samples are characterized by LREE-enriched patterns with negative Eu anomalies and have negative ε Nd (t) values (-0.4 – −1.4), which suggest that they were derived from partial melting of fertile mantle peridotite metasomatized by adakitic melts. The ∼ 2.44 Ga alkali feldspar granite samples have negative ε Nd (t) values (-4.0 – −1.9) and show geochemical characteristics of A-type granites, indicating an extension background. The distinct geochemical characteristics of ca. 2.46 – 2.44 Ga Guyang adakatic granodiorite, Nb-enriched monzonic diorite and A-type alkali feldspar granite suggest that a slab window was opened in the southern margin of the Yinshan Block. The gabbros were emplaced at ∼ 2.41 Ga revealed by U-Pb dating. The enriched LREEs and relatively flat HREEs patterns with negative Nb-Ta anomalies of gabbros indicate a subducting tectonic setting. Their high Ba/Th and low Nb/Y ratios imply that the mantle source was metasomatized by slab-derived fluids. This special rock association not only constrains the tectonic evolution in the southern margin of the Yinshan Block, but also indicates modern-style subduction operated already in the early Paleoproterozoic. [ABSTRACT FROM AUTHOR]