Abstract

RODRIGUEZ-CAMPERO, Cecilia; GARFIAS, Jaime; MARTEL, Richard  and  NAVARRO, Ignacio. Geological and hydrological features associated to fracturing in the Toluca Valley basin. Bol. Soc. Geol. Mex [online]. 2023, vol.75, n.1, e251122.  Epub May 25, 2024. ISSN 1405-3322.  https://doi.org/10.18268/bsgm2023v75n1a251122.

Excessive groundwater pumping in the Toluca Valley, Mexico, has resulted in regional subsidence and manifestation of ground fissures in the last 20 years. Such discontinuities result in damage to infrastructure and economic losses. This study evaluates the geological structure of the basin, the distribution of piezometric gradients, and its influence on the generation of faults and fractures. A regional three-dimensional geological model was developed using driller’s logs and published cross-sections. Stratigraphic data have been reinterpreted and classified to defined layers with similar hydraulic and mechanic characteristics. The hydraulic-head distributions were replicated through geostatistical analysis for the period 1975-2018. Piezometry results reflect the highest negative gradients in areas near fractures. The 14 layers geologic model show a highly irregular fractured aquifer specially under the Toluca city center and San Pedro Totoltepec location. The presence of volcanic domes, the existence of materials susceptible to consolidation, in addition to the location of piezometric descents in areas around the ruptures, are suggested as characteristic factors controlling the location and generation of faults and fractures. The geological model obtained in this study will be applied to support future groundwater flow modelling.

Keywords : Toluca aquifer; ground fissures; groundwater flow; tridimensional geologic model.

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