HR: 0800h
AN: GP21A-15    [Abstracts]
TI: Mexico City Top Soils Magnetic Properties and Geochemical Characteristics as Pollution Indicators
AU: * Martinez-Pichar, E
EM: erick160180@yahoo.com.mx
AF: Universidad Nacional Autonoma de Mexico, Lab. Paleomagnetismo, Instituto de Geofisica, Ciudad Universitaria, col. Coyoacan, Del. Coyoacan, Mexico, DF 04150, Mexico
AU: Soler-Arechalde, A M
EM: anesoler@geofisica.unam.mx
AF: Universidad Nacional Autonoma de Mexico, Lab. Paleomagnetismo, Instituto de Geofisica, Ciudad Universitaria, col. Coyoacan, Del. Coyoacan, Mexico, DF 04150, Mexico
AU: Acosta, T
AF: Universidad Nacional Autonoma de Mexico, Lab. Paleomagnetismo, Instituto de Geofisica, Ciudad Universitaria, col. Coyoacan, Del. Coyoacan, Mexico, DF 04150, Mexico
AU: Morton-Bermea, O
EM: omorton@geofisica.unam.mx
AF: Universidad Nacional Autonoma de Mexico, Lab. Paleomagnetismo, Instituto de Geofisica, Ciudad Universitaria, col. Coyoacan, Del. Coyoacan, Mexico, DF 04150, Mexico
AU: Hernandez-Alvarez, E
EM: aeliza@geofisica.unam.mx
AF: Universidad Nacional Autonoma de Mexico, Lab. Paleomagnetismo, Instituto de Geofisica, Ciudad Universitaria, col. Coyoacan, Del. Coyoacan, Mexico, DF 04150, Mexico
AU: Urrutia-Fucugauchi, J H
EM: juf@geofisica.unam.mx
AF: Universidad Nacional Autonoma de Mexico, Lab. Paleomagnetismo, Instituto de Geofisica, Ciudad Universitaria, col. Coyoacan, Del. Coyoacan, Mexico, DF 04150, Mexico
AB: Metal pollution of soils by human activities is one of the greatest environmental problems, and Mexico City urban area is not the exception. The geochemical methods are widely employed, but they are expensive and time consuming. The correlation between the magnetic minerals contents and the pollutants allow employing rock magnetism methods to determine the rate and spatial variations of them. We collected more than 120 samples from roadways and parks covering an area of 160 km². Magnetic measurements were carried out on routine magnetic parameters, including low frequency mass magnetic susceptibility (χ), frequency dependence susceptibility (χ_fd) , anhysteretic remanent magnetization (ARM) and isothermal remanent magnetization (IRM). Correlation factors between χ and several metals were obtained. With Pb the correlations factors are the highest. Intermediate values were obtained with Al₂O₃, Na₂O, Sr, Ba, Cu, Zn and Cr+Ni. The lower factors have been obtained with MgO, CaO, K₂O, P₂O₅, Zr, and V. The values of χ are ranging between 49 and 952 x 10^-8 SI. Parameters from IRM, ARM and hysteresis loops were analyzed in order to distinguish pollution sources and to define better correlation factors between magnetic properties and geochemical contents.
DE: 1065 Major and trace element geochemistry
DE: 1512 Environmental magnetism
DE: 1540 Rock and mineral magnetism
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Joint Assembly