Twelve mafic dyke swarms crop out in Hebei, Shanxi, Shandong, and Anhui provinces within the Taihang-Da Hinggan Mountains and Tan-Lu (Tan-Lu) magmatic belts, China. Here, we present new zircon LA-ICP-MS U-Pb age, geochemical, and Sr-Nd-Pb isotopic data for these dykes. The dykes formed between 128. 1 +/- 1. 2Ma and 115.0 +/- 0. 8Ma, and have typical doleritic textures. They are enriched in the light rare earth elements, some large ion lithophile elements (LILE; e. g., Rb, Ba, and Sr), Pb, and Th, and are depleted in Nb, Ta and Ti. The dykes have high initial 87 S r/86 Sr ratios (0. 7056 similar to 0.7105), negative eNd (t) values (-15.5 to -12. 4), relatively constant initial Pb isotopic ratios (16.45 similar to 16. 49, 15.44 similar to 15. 51, and 36.49 similar to 36.53 for Pb-206/ Pb-204, Pb-207/Pb-204, and Pb-208/(204) Pb, respectively), and relatively old Nd model ages (t(DM2)(Nd) =1.82 similar to 2. 69Ga). These results indicate that the dykes were derived from magmas generated by a certain extent partial melting (1. 0% similar to 5. 0%) of an EM1-like garnetlherzolite mantle source. These magmas fractionated olivine, clinopyroxene, and hornblende prior to emplacement, and assimilated minimal amounts of crustal material. Several possible models have been proposed to explain the destruction of the North China Craton (NCC) and the origin of Mesozoic magmatism. Here we propose a new model for the origin of these dykes, involving the foundering of eclogite from thickened lower crust and ongoing collision between the Paleo-Pacific Plate and the NCC.