This study investigates the age and tectonic environment of metamorphosed volcanic-sedimentary sequences in China's East Kunlun Orogen, specifically within the Naichitai mélange. Through comprehensive geochemical analysis of whole-rock samples, Lu-Hf isotopic investigations, and U-Pb dating of detrital zircons, we've pinpointed the source materials, sedimentary origins, and depositional period of these precursor rocks. The most recent detrital zircon samples show a weighted average age of 421.1 ± 7.0 million years, with individual measurements falling between 436 and 412 million years—strong evidence for a late Silurian depositional boundary. The εHf(t) values for these zircons fall within a narrow window of 0.67 to 5.09 (averaging 2.54), strongly suggesting their formation from newly formed continental crust.Their TDM1 model ages (1022–838 Ma) suggest magmatic origins tied to crust-mantle interactions during the Grenvillian Orogeny—a key phase in Rodinia's assembly. Considering the area's tectonic history, we identify the protoliths as silt-sand deposits formed at a passive continental edge.Our findings indicate that subduction in the central Kunlun Ocean terminated by ~ 430 Ma, shifting the East Kunlun region into an extensional intraplate regime. By the latter stages of the Silurian period, a passive continental margin had formed along the southern edge of the South Kunlun Block. This study sheds fresh light on the geological transformation of the East Kunlun region while bolstering the hypothesis of a tectonic link between the South Kunlun Block and the South China Block. The findings offer compelling evidence that reshapes our understanding of this ancient geological relationship.