Abstract: The orthoamphibole rocks exposed in the Hengshan-Wutai area are characterized by a distinctive mineral assemblages (anthophyllite + garnet) and unique geochemical signatures (enriched in Fe, Mg and Al, depleted in Ca and alkalis). However, their protolith and petrogenesis remain a subject of long-standing debate due to the perturbed effects of subsequent metamorphism and tectonic deformation. In this study, we conducted a systematic investigation of these rocks by integrating detailed field surveys and petrographic observations with machine learning algorithms and geochemical fingerprints. For the machine learning techniques, we constructed a geochemical database comprising Archean basalts and pelitic rocks and designed a Random Forest classification model by training classifers with the geochemical compositional database. Combined with Isocon mass balance analysis, which should be possible to formulate the relationships between immobile and potentially mobile elements, the trained classifers enable to classify the orthoamphibole rocks exhibiting a strong genetic affinity with the Archean basalts. Moreover, their rare earth element (REE) patterns and elevated Co and Sc concentrations are consistent with those of Archean basalts and distinct from typical pelitic rocks. Isocon mass balance analysis indicates that the protoliths underwent a net mass loss of approximately 26%, accompanied by intense leaching of mobile components such as Ca and Na. Notably, the decoupling of Zr–Hf, the anomalous enrichment of Th, and the scattered distribution of Zn suggest that the precursors underwent mechanical sorting during sedimentation. Additionally, zircon U–Pb dating yielded a primary detrital age peak at ～2520 Ma, suggesting a uniform provenance derived mainly from local ～2.52 Ga magmatic rocks. Metamorphic zircon ages cluster around 1.92 Ga, recording a Paleoproterozoic collision event in the North China Craton. Consequently, we propose that the protoliths of the Hengshan anthophyllite rocks was a mafic-rich sedimentary rock derived from Archean basaltic sources. These rocks formed through chemical weathering of the basaltic source, followed by depositional processes and subsequent amphibolite-facies metamorphism at ~1.92 Ga.