HR: 0830h
AN: GP41A-06    [Abstracts]
TI: First Archeomagnetic Intensity Results from Ancient Guatemala Potteries
AU: * Alva-Valdivia, L M
EM: lalva@geofisica.unam.mx
AF: Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, Del. Coyoacan, Mexico, DF 04510 Mexico
AU: Morales, J
EM: jmorales@geofisica.unam.mx
AF: Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, Del. Coyoacan, Mexico, DF 04510 Mexico
AU: Goguitchaichvili, A
EM: avto@geofisica.unam.mx
AF: Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, Del. Coyoacan, Mexico, DF 04510 Mexico
AU: Hatch, M P
EM: arqueolo@uvg.edu.gt
AF: Dpto. Arqueologia, Universidad del Valle, Av. Simon Bolivar 205, Guatemala, Gua Guatemala
AB: Archeointensity results from 10 pottery fragments are reported as a first trial to create the intensity secular variation curve for the Preclassic period from 900 BC to 200 AD. Hysteresis loops, IRM-DIRM and Curie temperature analysis indicate that magnetite is the main carrier of magnetic signal in pottery, and PSD grain-size the predominant. The fragments were analyzed using the Thellier and Thellier method modified by Coe (1967). Intensity values were corrected for thermoremanent magnetization (TRM) anisotropy and cooling rate dependence of TRM acquisition. Although our results are still not numerous, they have good technical quality determination attested by the reasonably high Coe et al's quality factors. Natural remanent magnetization fraction f used for determination ranges between 0.35 to 0.92 and the quality factor q from 3 to 21 being generally greater than 5. The site mean archeointensities are ranging from 38.3 to 45.8 T. Because no archeointensity reference curve is available in Mesoamerica, Korte et al.'s (2004) global geomagnetic intensity models are used to better constraint the ages of studied pottery.
DE: 1503 Archeomagnetism
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2005 Joint Assembly