HR: 0800h
AN: NS31A-09    [Abstracts]
TI: Shallow Exploration Geophysics Study in Tocuila, Texcoco, Basin of Mexico
AU: * Arciniega-Ceballos, A
EM: maac@geofisica.unam.mx
AF: Instituto de Geofisica, UNAM, Cd Universitaria, Mexico City, DF 04510, Mexico
AU: Hernandez-Quintero, E
EM: estebanh@geofisica.unam.mx
AF: Instituto de Geofisica, UNAM, Cd Universitaria, Mexico City, DF 04510, Mexico
AU: Morett-Alatorre, L
EM: l_morett@yahoo.com.mx
AF: Universidad Autonoma de Chapingo, Chapingo, Texcoco, Mex , Mexico
AU: Soler-Arechalde, A
EM: anesoler@geofisica.unam.mx
AF: Instituto de Geofisica, UNAM, Cd Universitaria, Mexico City, DF 04510, Mexico
AU: Chavez, P
EM: kiuvoc@hotmail.com
AF: Instituto de Geofisica, UNAM, Cd Universitaria, Mexico City, DF 04510, Mexico
AU: Ayala, G
EM: gabos04@hotmail.com
AF: Instituto de Geofisica, UNAM, Cd Universitaria, Mexico City, DF 04510, Mexico
AB: Tocuila town is a paleontological and archeological area located in Texcoco Lake at southeastern of Mexico City. The recent findings of Late Pleistocene megafauna and prehistoric human remains buried nearby Tocuila town invite us to apply shallow geophysics methodologies to identify and define shallow geological structures controlling the volcano sedimentary deposits. In this work we present the preliminary results of the seismic and magnetic exploration campaigns in an area characterized by predominant soft soil deposits. The seismic refraction exploration arrays were delimited by urban conditions. Profiles consist on 12-24 geophones with 1 m or 2 m spacing interval along 50 m to 200 m transect in open fields and unpaved roads. We used a Geometrics StrataVisor NZ seismograph. The magnetic surveying was developed in two phases. The first one was developed in a 100 X 100 m grid approximately. Several profiles were surveyed and we could recognize high frequency surface magnetic anomalies coming from quite well identified sources such as isolates metallic structures, or urban constructions, likewise low-powered lines in the southern edge of this area. In the first phase we used two Geometrics magnetometers (model G-856). For the second one an overhouser magnetometer with GPS system integrated was used (GEM-Systems). The combination of the two methodologies allowed us to identify and delimit pre-hispanic structures with geometries like Tlatels and paleo-channels associated with megafauna remains. We present preliminary proposed models of shallow structures at range depth between 2-10 m.
UR: http:www.geofisica.unam.mx
DE: 0999 General or miscellaneous
SC: Near-Surface Geophysics [NS]
MN: 2007 Joint Assembly