## 5 Conclusions  
In this work, different direct and indirect methods were used in an integrated way to analyse the capacity of each method in the modelling of geological structures. For this purpose, the northern boundary of the Bailen basin in the vicinity of Bar\(\acute{\text{o}}\)s de la Encina (southeast Spain) was chosen as study site. The following three different geophysical techniques were used: seismic reflection, time-domain electromagnetic (TDEM) and magnetic methods. These geophysical techniques were calibrated with available direct information, both from outcrop data and from boreholes. The effectiveness of seismic reflection in characterizing sedimentary basins lies in its ability to provide high-resolution images of geological structures. In the seismic reflection profiles, abrupt changes are observed in the amplitude of the wave associated with the different lithologies of the sedimentary cover, as well as the acoustic basement associated with the Palaeozoic basement. By means of this method, two faults are detected that caused the subsidence of the eastern sector of the basin (the Bailen graben). The TDEM technique is very versatile and can be used with different configurations and ranges of amplitude, voltage, time or device and loop size, depending on the depths at which the investigation is focused. Although its spatial resolution is lower compared to seismic reflection, it is a method that is easier to implement than the previous one. However, the interpretation of TDEM data requires complex mathematical models that do not provide a unique solution, so it requires the integration of the results obtained with other geophysical methods or direct geological data. In the case of TDEM, the best solution would be, a priori, the one that presents a better fit between measured and calculated data, characterized by low residual error values. The validation by means of direct geological data, from boreholes, and indirect data, obtained from the reflection  
Figure 7: Total field magnetic anomaly profiles. Their positions are shown in Figure 6.  
seismic profile, confirms the adequacy of the geoelectric model obtained. In this study, a good fit between the seismic and electromagnetic data was generally found. This method made it possible to locate the position of the upper aquifer, associated with calcarenites, breccias or polygenic conglomerates: the top of this unit is characterized by a sudden increase in resistivity values associated with these lithologies in comparison to the upper marks. However, the characterization of the lower aquifer under the Triassic clays was not so evident. The TDEM method also made it possible to detect the depth of the Palaeozoic basement under the sedimentary cover, as well as the presence of the two aforementioned faults. The effectiveness of the TDEM analysis in calculating this depth is attributed to the notable resistivity contrast between the infilling materials and the underlying phyllitic basement rocks. This contrast in resistivity serves as a key parameter, enabling the differentiation and characterization of distinct geological layers also identified in the seismic reflection profile, thereby facilitating accurate depth assessments. The magnetic method was chosen because of its efficacy to discern among rock bodies with different magnetic susceptibilities, and that provides a way of delineating subsurface geologic features as faults over broad areas. Magnetic prospecting revealed two alignments of anomalies in the geological map, which are associated with two fault phases (N30\({}^{\circ}\) E and N60\({}^{\circ}\) E). Both fault directions have been mapped in the boundaries of the Bailen basin when they affect the Palaeozoic basement, but they are not mappable in the Tertiary marly facies. These new data provide information on the orientation of linear structural features and allow to infer previously unknown faults.