The assemblage, growth, and breakup of global- scale supercontinents profoundly influence Earth' s systems. These events not only lead to significant changes in lithospheric composition and structure but also impact the surface environments such as the atmosphere, hydrosphere, and biosphere over geological timescales. The late Mesoproterozoic to early Neoproterozoic interval was crucial for the amalgamation of the Rodinia supercontinent, marking the onset of global- scale plate cold subduction and ultrahigh pressure metamorphism. However, scarcity geological records of magma- tectonic events in the North China Craton (NCC) during this period hinder its correlation with Rodinia and paleogeographic reconstruction. Extensive mafic sill and dyke emplacement in the Xuhuai, Dalian, and Korea Pyongnam areas provides a valuable opportunity to address these knowledge gaps. This study focuses on the petrology, geochronology, and geochemistry of mafic sills in the Xuhuai area to decipher their petrogenesis, tectonic setting, and the role of the NCC in Rodinia assembly. Our results indicate that the diabase sills emplaced during the early Neoproterozoic (940~890 Ma), spanning about 50 Ma. These sills can be subdivided into two stages: the 940~920 Ma high- Ti group, emplaced into the middle part of the Huaibei Group (Niyuan Formation), and the 920~890 Ma low- Ti group, emplaced into the upper part of the Huaibei Group (Wangshan Formation). Most diabase samples exhibit tholeiitic affinities, and some high- Ti samples display alkali characteristics. Trace element analysis reveals LREE enrichment with (La/Yb) N ratios ranging from 2.5 to 8.6. High large ion lithophile elements (e. g. , Rb, Ba) and high field strength elements (e. g. , Zr, Hf, Ti) contents are observed on PM- normalized spider diagrams, with a slight Nb- Ta trough (Nb/La=0.63~1.12, mostly below 1). High- Ti samples share OIB- like chemical compositions, while low- Ti samples display CFB- like elemental signatures. Despite these differences, both groups are associated with an intraplate extensional tectonic setting. Isotopically, the diabase shows heterogeneous Sr- Nd- Hf- O isotopic compositions. The high- Ti group exhibits more radiogenic Nd- Hf isotopes compared to the low- Ti group. Moreover, a subtle decoupling exists between whole- rock Nd and zircon Hf isotopes. Heavy oxygen isotope signatures in zircons suggest that the lithospheric mantle source regions of the diabase underwent melt/fluid metasomatism derived from dehydration melting of the subducted slab. Integrating the exotic provenance revealed by detrital zircon ages in clastic strata and the rapid latitudinal wander calculated from paleomagnetism, the large igneous province (LIP) model may not be the most plausible interpretation. Instead, a model involving plate subduction retreat or the big mantle wedge model could potentially reconcile the diverse observations obtained through geochemistry, paleomagnetism, and sedimentology.