GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 1.1 - POSTER GNGTS 2023 The innovative approach proposed in this project is to use for the first time in the Dílar Fault, the combination of different geophysical methods in conjunction with classical geological techniques and digital photogrammetry techniques to characterize this active normal fault (Sanz de Galdeano et al., 2003). The extreme degree of the lithological, textural and structural heterogeneity of the area requires the use of several techniques: using different signals with different spatial wavelengths that provide complementary information on the physical properties of the rocks. Fig. 1: A) Geological map of the Granada Basin and its position in the Betic Cordillera. The white square represents the study area. B) Photograph of the outcropping part of the Dílar Fault. The project Workflow The first approach consisted in remote analysis of the study area was carried out by using satellite images and digital elevation models available with a resolution of two meters per pixel. This cost-effective remote analysis allowed the elaboration of a geological map of the study area, where the metamorphic basement could be differentiated from the sedimentary infill, and different sedimentary units previously described in the bibliography. The exposed fault trace was reconstructed at a detailed level and its inferred extension was mapped based on a geomorphological analysis. The recent fault throws were analyzed through the construction of profiles of the surface drainage valleys, being able to determine the presence of knikpoints and knik zones in some of them. The second stage consisted of field data collection. The geophysical data acquisition was carried out and followed a multi-parametric approach. On a regional scale, more than 150 gravimetric stations and more than 100 magnetometry measurements were taken. To ensure the highest quality after data processing, the altitudes of the measuring stations were taken by differential global navigation satellite systems (GNSS). This is especially important for gravimetric data, where errors in station altitudes can lead to large variations after data correction.