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Boletín de la Sociedad Geológica Mexicana Volumen 69, núm. 2, 2017, p. 279 ‒ 298 |
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Geoelectrical and Electromagnetic Methods Applied to Paleolimnological Studies: Two Examples from Desiccated Lakes in the Basin of Mexico
Matthias Bücker, Socorro Lozano García, Beatriz Ortega Guerrero, Margarita Caballero, Liseth Pérez, Lizeth Caballero, Carlos Pita de la Paz, Alfredo Sánchez-Galindo, Francisco Jesús Villegas, Adrián Flores Orozco, Erik Brown, Josef Werne, Blas Valero Garcés, Antje Schwalb, Andreas Kemna, Edgar Sánchez-Alvaro, Norberto Launizar-Martínez, Antonio Valverde-Placencia, Fernando Garay-Jiménez
Matthias Bücker
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Fachbereich Geophysik, Steinmann-Institut, Universität Bonn, Mecken heimer Allee 176, 53115 Bonn, Germany.
Forschungsgruppe Geophysik, Department für Geodäsie und Geoinformation, TU-Wien, Gußhausstr. 25-29, 1040 Wien, Austria.
Socorro Lozano García
Liseth Pérez
Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, C.P. 04510, Ciudad de México, México.
Beatriz Ortega Guerrero
Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria, C.P. 04510, Ciudad de México, México.
Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, C.P. 04510, Ciudad de México, México.
Margarita Caballero
Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria, C.P. 04510, Ciudad de México, México.
Lizeth Caballero
Departamento de Física, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, C.P. 04510, Ciudad de México, México.
Carlos Pita de la Paz
Alfredo Sánchez-Galindo
Francisco Jesús Villegas
Geotem Ingeniería S.A. de C.V., Alhelí Mz.7 Lt.13-A, Col. Ejidos San Pedro Mártir, C.P. 14640, Ciudad de México, México.
Adrián Flores Orozco
Forschungsgruppe Geophysik, Department für Geodäsie und Geoinformation, TU-Wien, Gußhausstr. 5-29, 1040 Wien, Austria.
Erik Brown
Large Lakes Observatory and Department of Earth and Environmental Sciences, University of Minnesota Duluth, 2205 E. 5th St., Research Laboratory Building 207, Duluth, MN 55812, USA.
Josef Werne
Department of Geology and Environmental Sciences, University of Pittsburgh, 505 SRCC, 4107 O’Hara Street, Pittsburgh, PA 15260, USA.
Blas Valero Garcés
Instituto Pirenaico de Ecología – CSIC, Avda. Montañana 1005, Zaragoza 50059, Spain.
Antje Schwalb
Institut für Geosysteme und Bioindikation, Technische Universität Braunschweig, Langer Kamp 19c, 38106 Braunschweig, Germany.
Andreas Kemna
Fachbereich Geophysik, Steinmann-Institut, Universität Bonn, Meckenheimer Allee 176, 53115 Bonn, Germany.
Edgar Sánchez-Alvaro
Norberto Launizar-Martínez
Antonio Valverde-Placencia
Fernando Garay-Jiménez
Departamento de Sismotectónica y Exploración Geofísica, Gerencia de Estudios de Ingeniería Civil, Comisión Federal de Electricidad, Augusto Rodín 265, Col. Noche Buena, Del. Benito Juárez, C.P. 03820, Ciudad de México, México.
Abstract
Paleolimnological studies require a broad understanding of the geometry and depth of the sedimentary fill of lake basins prior to coring campaigns. Seismic methods are routinely employed for the indirect characterization of lake-bottom sediments. However, the use of seismic methods might occasionally be limited due to surface conditions or poor seismic contrasts between the stratigraphic units, which lead to data quality that is too poor to provide sufficient information for the selection of drill sites. Sources of cultural noise are one of the main reasons why seismic methods fail in study areas near or within large cities, such as Mexico City. Under certain conditions, electrical and electromagnetic methods might be a suitable substitute or complement to seismic exploration, as they respond to different physical properties of the subsurface. To evaluate the applicability of such methods, here we present two recent case studies from the desiccated lakes Chalco and Xochimilco both located in urban areas within the Basin of Mexico where electrical resistivity tomography (ERT), transient electromagnetic (TEM) and magnetotelluric (MT) soundings were conducted for the characterization of lake basement and lacustrine sediments. In both examples, the results of the geophysical exploration contributed valuable stratigraphic information for the following drilling and core recovery, which highlights the potential of electrical and electromagnetic methods in paleolimnological studies.
Keywords: Geophysics, electrical resistivity tomography, electromagnetic methods, paleolimnology, lacustrine sediments, Mexico.
