Modelo geológico del Acuífero de Medina del Campo a partir de inversión gravimétrica 3D (Cuenca del Duero)

Abstract

[EN] This contribution summarizes the geophysical research carried out to characterize the groundwater body (GWB) of Medina del Campo, located in the SE part of the Duero Basin, which corresponds to a multilayer detrital aquifer. The 3D model obtained displays the distribution of Miocene, Paleogene and Cretaceous sediments and the structure of the paleozoic basement in this sector of the basin. The 3D geological model was built with the Geomodeller software and comprises geological mapping, vertical electrical soundings, time domain electromanetic soundings and gravimetric data. An important methodological aspect of this work is the use of gravimetric forward modelling and gravimetric 3D inversion as main tools. The 3D geological model reveals that the subsurface of the Medina del Campo GWB is not homogeneous but is constituted by E-W to ENE-WSW depressions and highs mainly associated with pop-up and pop-down structures. In addition, NE-SW vertical faults developed depressions; like the Villorio-Alba fault with an associated displacement of 850 meters. The maximum depths of the basement are located to the SE part of Medina del Campo and south of Valladolid, where they reach values of more than 2000 m depth. In the surroundings of Medina del Campo, the basement has an EW trend and reaches about 1000 m depth. The Paleogene unit has a more constant sedimentary thickness in the center of the Basin with values of about 500 m, whereas the Miocene one shows greater Variations reaching up to 1500 m of thickness.This 3D geological model represents an important advance in the knowledge of the geometry of this GWB. It will have implications in future flow models of this part of the basin and in the definition of the resources and reserves of this GWB.