Testing Non-Conventional Archaeomagnetic Materials: Mural Paintings and Stucco as a Unified Geomagnetic Field Recorder at Teotihuacan, Mesoamerica

• Mural paintings and their stucco supports are tested as a single non-conventional material for archaeomagnetic studies at Teotihuacan. • Remanent magnetization is essentially carried by magnetite or Ti-poor titanomagnetite grains. Hematite is also present in few samples but its contribution is minor. • Despite relatively large directional dispersion, stable archaeomagnetic directions were obtained and provide broad chronological constraints for the sampled murals. • The combined mural–stucco assemblage approach expands the range of archaeological materials usable for archaeomagnetic investigations in Mesoamerica. Teotihuacan, the largest urban center of ancient Mesoamerica, remains one of the most intensively studied archaeological sites in Mexico, yet its internal chronology continues to be debated. Among its most distinctive cultural features are omnipresent mural paintings, executed on lime plaster (stucco) surfaces that served as their structural support. In this study, we analyze for the first time mural pigments and stuccos together as a single archaeomagnetic assemblage to evaluate their potential as geomagnetic recorders. Three mural paintings were sampled near the Square of the Moon and the Street of the Dead using orientation techniques adapted from standard paleomagnetic procedures. Magnetic mineralogy experiments revealed a mixture of magnetite (or Ti-poor titanomagnetite) and hematite as carriers of remanence, with magnetite generally dominating. Of 43 specimens analyzed, 19 yielded reasonably well-defined characteristic remanent magnetization (ChRM) directions after alternating-field demagnetization. Although within-site scatter limited the precision of archaeomagnetic dating. Comparisons with the regional curve for Mesoamerica and the global geomagnetic model (SHAWQ.2K) produced two relatively large chronological intervals: (i) ∼300–400 AD, consistent with previously dated murals, and (ii) ∼550–650 AD, corresponding to major chronological episodes associated with the decline of Teotihuacan. These results demonstrate that mural–stucco assemblages can preserve reliable archaeomagnetic signals, expanding the range of datable materials and offering new chronological anchors to refine Teotihuacan’s contested history.