<p>The Early Jurassic (200–180&#xa0;Ma) marked the onset of Paleo-Pacific plate subduction beneath northeastern Asia. However, its impact on the lithosphere and mineralization of the eastern Central Asian Orogenic Belt (CAOB) remains poorly understood. By leveraging magmatic-hydrothermal Cu-Au deposits as tracers of continental dynamics, this study deciphers the influence of early Paleo-Pacific plate subduction on metallogeny through integrated geochemical and machine learning analyses of the Early Jurassic Yanghuidongzi Cu and Lianzhushan Au-Sb-W deposits. All evidence from the Yanghuidongzi deposit supports its classification as an intermediate- to low-temperature vein-type Cu system, precluding a porphyry model. Similarly, geological features, stibnite geochemistry, and fluid inclusion temperatures from the Lianzhushan deposit collectively establish an intermediate- to low-temperature vein-type Au-Sb-W system, which differs from typical arc-related epithermal deposits. The sulfide δ³⁴S values (− 4.80‰ to − 2.77‰) from both deposits indicate a magmatic S source. In contrast, the Hg isotope characteristics of both deposits, marked by slightly positive δ²⁰²Hg and negative Δ¹⁹⁹Hg, support crustal remobilization in an extensional setting. Regional metallogenic synthesis reveals that Early Jurassic mineralization in the eastern CAOB was dominated by skarn-type Fe-W-Mo, porphyry Mo, and intermediate- to low-temperature hydrothermal vein-type Cu-Au-Sb-W deposits, while lacking arc-related Cu-Au deposits. This implies that early Early Jurassic mineralization was controlled by Paleo-Pacific back-arc extension, prior to deep slab underthrusting. This timing contrasts with coeval arc-related porphyry Cu deposits in the northern eastern CAOB, which were generated by Mongol-Okhotsk oceanic plate subduction.</p>