HR: 09:39h
AN: GP51A-07    [Abstracts]
TI: New archeointensity results from Teotihuacan (Central Mexico)
AU: * Rodriguez, M
EM: maria@geofisica.unam.mx
AF: Instituo de Geofisica, UNAM, Ciudad Universitaria s/n, Mexico, Mexico
AU: Gogichaishvili, A
EM: avto@geofisica.unam.mx
AF: Instituo de Geofisica, UNAM, Ciudad Universitaria s/n, Mexico, Mexico
AU: Morales, J
EM: jmorales@geofisica.unam.mx
AF: Instituo de Geofisica, UNAM, Ciudad Universitaria s/n, Mexico, Mexico
AU: Manzanilla, L
EM: lmanza@servidor.unam.mx
AF: Instituto de Investigaciones Antropologicas, Ciudad Univeristaria s/n, Mexico, Mexico
AU: Chauvin, A
EM: Annick.Chauvin@univ-rennes1.fr
AF: Laboratoire de Paleomagnetisme, Geoscience Rennes, Campus Beaulieu, Rennes, France
AU: Urrutia, J
EM: juf@geofisica.unam.mx
AF: Instituo de Geofisica, UNAM, Ciudad Universitaria s/n, Mexico, Mexico
AU: Robles, J
EM: jasinto_robles@yahoo.com
AF: Instituto Nacional de Antropologia y Historia, Morelia, Michoacan, Morelia, Mexico
AB: We carried out systematic rock-magnetic and archeointensity invetigations on 84 pottery fragments (about 549 samples) of Teotihuacan ceramics. Three localities are sampled: Xalla, Teopancazco and Cueva de las Varillas. The principal aim of this study is to try to establish first archeointensity reference curve for Mesoamerica from 300 a.C. and 1500 d.C. The samples selected are related to about 50 C14 and AMS radiometric data available. Thus there are almost ideal conditions to know absolute geomagnetic intensity variation trough time. Rock-magnetic investigation included susceptibility vs temperature and hystresis measurements. In addition some X-Ray and microscopy studies were performed on selected specimens. The samples are characterized by stable remanent magnetization observed upon both thermal and alternating field demagnetizations. Both Ti-poor and Ti-rich titanomagnetites are responsible for the magnetization. 61 out 84 fragments yielded acceptable archeointensity results yielding an extremely high success rate. The cooling rate and anisotropy correction were applied to all samples. The mean intensities found range from 72.8 to 15.9 microT showing very low within fragment dispersion.
DE: 1500 GEOMAGNETISM AND PALEOMAGNETISM
DE: 1503 Archeomagnetism
DE: 1519 Magnetic mineralogy and petrology
DE: 1521 Paleointensity
DE: 1522 Paleomagnetic secular variation
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Joint Assembly