A detailed rock-magnetic and archaeomagnetic investigation on wattle and daub building (Bajareque) remains from Teuchitlán tradition (nw Mesoamerica)

We carried out a detailed mineral magnetic and archaeomagnetic investigation on wattle and daub (locally known as Bajareque) building remains recovered at Teuchitlán archeological site (Jalisco, Mexico) in order to estimate the suitability of such material for Thellier double heating absolute geomagnetic intensity determinations and to contribute to the still incipient archaeomagnetic database for Mesoamerica. The single-domain Ti-poor titanomagnetite and hematite seem to be main magnetic carriers in most of samples. Although the presence of hematite is confirmed for all samples, its contribution to the remanent magnetization seems negligible and the most part of remanent magnetization is carried by almost magnetite phase. All 42 analyzed Bajareque samples yielded technically acceptable archaeointensity determination, which is probably a unique case since a 100% of success rate is reached. Present study underlines the exceptional magnetic properties of Bajareque samples and their high suitability for absolute geomagnetic intensity determinations. Selected mean archeointensity data currently available for Mesoamerica show unusually high dispersion, which makes it difficult to make any firm conclusion about the evolution of Earth's magnetic field through archeological time.