Magnetic properties and electron spin resonance of Ecuadorian obsidians. Application to provenance research of archeological samples

Abstract Obsidians from major Ecuadorian sources were analyzed by SQUID magnetometry and electron spin resonance (ESR). The association of these two techniques permits to differentiate obsidians from the sources of Cotopaxi volcano and from the Quiscatola and Mullumica–Callejones sources of the Chacana caldera, taking into account various parameters arising from the M vs. H cycles and the X-band ESR spectra. The analysis of 27 archeological samples coming from the prehispanic site of La Mana allowed us to infer that most of them come from the Mullumica–Callejones source.