Gravimetric and morpho-structural analyses in the superhot geothermal system Los Humeros: an example from central Mexico

Geothermal Energy, vol. 12

Abstract

Abstract The influence of deep and regional geological structures is becoming increasingly important in superhot geothermal systems due to their proximity to the transition between brittleness and ductility. In the Los Humeros geothermal field in Mexico, where subsurface fluids reach temperatures of over 350 °C, the surface structures resulting from the collapse of calderas have so far only been interpreted at the local scale. The aim of this work is to place the recent tectonic and volcano-tectonic geomorphologic evolution and structures in the Los Humeros volcanic area in a regional context. NE- and NW-striking dominant structures resulting from a morpho-structural analysis on a regional scale are confirmed by negative and positive anomalies, respectively, after Butterworth filtering of gravity field data with different wavelengths over a local area of about 1000 km2. By analyzing the slip and dilation trends of the observed directions, we show the relevance of the regional context for reservoir exploration. The magnitudes of the principal stresses we estimate indicate a trans-tensional fault regime, a combination of strike-slip and normal faulting. The structures derived from the gravity and morpho-structural analyses, which are parallel to the maximum horizontal stress, have the highest potential for tensile and shear failure. Therefore, the corresponding negative gravity anomalies could be related to fracture porosity. Consequently, we hypothesize that these structures near the transition between brittleness and ductility control fluid flow in the Los Humeros geothermal field.

Authors 10

1. Natalia Cornejo-Triviño

   Karlsruhe Institute of Technology · Technische Universität Darmstadt

   Affiliation as printed

   Institute for Nuclear Waste Disposal, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

   Institute of Applied Geosciences, Technical University of Darmstadt, Darmstadt, Germany

2. Domenico Liotta

   Institute of Geosciences and Earth Resources · National Research Council · University of Bari Aldo Moro

   Affiliation as printed

   Department of Earth and Geoenvironmental Sciences, University of Bari Aldo Moro, Bari, Italy

   Institute of Geosciences and Earth Resources, National Research Council (IGG-CNR), Pisa, Italy

3. Luigi Piccardi

   Institute of Geosciences and Earth Resources · National Research Council

   Affiliation as printed

   Institute of Geosciences and Earth Resources, National Research Council (IGG-CNR), Florence, Italy

4. Andrea Brogi

   Institute of Geosciences and Earth Resources · National Research Council · University of Bari Aldo Moro

   Affiliation as printed

   Department of Earth and Geoenvironmental Sciences, University of Bari Aldo Moro, Bari, Italy

   Institute of Geosciences and Earth Resources, National Research Council (IGG-CNR), Pisa, Italy

5. Michał Kruszewski Aachen Chair of Engineering Geology & Hydrogeology

   RWTH Aachen University

   Affiliation as printed

   Chair of Engineering Geology and Hydrogeology, RWTH Aachen University, Aachen, Germany

6. M. A. Pérez‐Flores

   Centro de Investigación Científica y de Educación Superior de Ensenada

   Affiliation as printed

   Center for Scientific Research and Higher Education (CICESE) , Ensenada , Mexico

   Earth Sciences Division ,

   Earth Sciences Division, Center for Scientific Research and Higher Education (CICESE), Ensenada, Mexico

7. Jonathan Carrillo

   Centro de Investigación Científica y de Educación Superior de Ensenada

   Affiliation as printed

   Earth Sciences Division, Center for Scientific Research and Higher Education (CICESE), Ensenada, Mexico

8. Philippe Calcagno

   Bureau de Recherches Géologiques et Minières

   Affiliation as printed

   French Geological Survey (BRGM), Orléans, France

9. Ingo Sass

   Technische Universität Darmstadt · GFZ Helmholtz Centre for Geosciences

   Affiliation as printed

   Geoenergy, German Research Centre for Geoscience (GFZ), Potsdam, Germany

   Institute of Applied Geosciences, Technical University of Darmstadt, Darmstadt, Germany

10. Eva Schill

    Karlsruhe Institute of Technology · Technische Universität Darmstadt

    Affiliation as printed

    Institute for Nuclear Waste Disposal, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

    Institute of Applied Geosciences, Technical University of Darmstadt, Darmstadt, Germany