Estudio multimétodo de arqueointensidad en materiales calentados bajo condiciones controladas

Abstract

A rock-magnetic and archeointensity study has been performed on ceramic, and brick samples bakedunder controlled conditions in an original kiln from an artisan workshop in western Mexico. Controlledconditions implied knowledge of the Earth’s magnetic field value at the site during the experiment, recordingof continuous temperature data at four different positions in the kiln during the whole heating-coolingprocedure and knowledge of the position of all studied artifacts in the kiln. Rock-magnetic experimentswere performed on the raw material used for the preparation of ceramic and brick samples as well as on thesynthetic archeological artifacts after baking. The experiments included measurement of thermomagneticcurves, hysteresis curves, isothermal remanent magnetization (IRM) acquisition curves and first-orderreversal curves (FORC). Magnetite seems to be the main carrier of remanence and hysteresis parameterratios suggest a pseudo-single domain structure, which may also indicate a mixture of single-domain andmultidomain grains.Archeointensity experiments were performed with the following methods: (i) Thellier-type double heatingmethod as modified by Coe (1967); (ii) multispecimen parallel differential pTRM method (Biggin andPoidras, 2006; Dekkers and Böhnel, 2006); microwave method (Walton et al., 1992) and domain-statecorrected multiple-specimen paleointensity determination technique (Fabian and Leonhardt, 2010).Determinations with all four methods yield good estimations of the local geomagnetic field strength