## 5 Results and Discussion  
Although microtremor [59] and seismic reflection [11] studies were carried out in previous studies, the first field gravity measurements of the region were made and a detailed Bouguer gravity anomaly map of the region was obtained. As mentioned in the introduction, the obtained map is detailed enough to be used in many studies, such as geothermal studies. Furthermore, previous studies were shallow compared to the data that has been obtained in our study. [PERSON], [PERSON], [PERSON] and [PERSON] [59] provided a research depth of approximately 800 m using microtremors and seismic reflection. Since the main source of the gravity method is the Earth's gravitational body forces, we managed to gather data from as deep as 3.22-18.5 km, and this is explained in the 'Spectral Analysis' section. As shown in Figure 2b, the average depth of earthquakes occurring in the basin is around 8-10 km, which falls inside our data limits. Although gravity measurements were performed on hard rock units in the north and south of the site, contrary to expectations, it presents relatively positive anomalies in the north, but negative anomalies in the south (Figure 1b). The source of these anomalies may be a much deeper tectonic structure. Further geophysical and geological studies could be conducted to reveal the nature of these anomalies. Figure 6: ED solutions for \({}^{\prime\prime}N=0^{\prime\prime}\) superimposed on topography map. ED depth solutions range from 230 m to 3320 m which are highly compatible with spectral analysis solutions. The sizes of the purple circles show the earthquake locations according to their magnitude. (Datum: WGS84 UTM Zone 36 N). The lineaments obtained from the HGM method of the study area and the lineaments obtained from the ED method were evaluated comparatively, and the consistency of those lineaments with the seismic activity in the region was examined. Linearities obtained by the results of the analysis were compared with the current earthquake locations that have been documented in the Eskisehir Basin. Earthquakes occurring between 1900 and 2019 were used for the study (Figure 2). In order to prevent the map from becoming overcrowded and unreadable, earthquakes with a magnitude of Mw 3.0 and above were compiled. At the same time, earthquakes with a magnitude of Mw 3.0 and above provide more consistent depth and location solutions for the study area. In total, forty-nine earthquakes were mapped within the framework of the mentioned criteria. There is a remarkably compatible relationship between the results of the edge detection analyses obtained from both the HGM and ED methods and the locations of the earthquakes in the region (Figure 7). However, if the determined lineaments represent faults, the determination of the types of the faults, and whether they are active or not, should be investigated by other geological and geophysical methods. It is important, in terms of consistency, for the edge detection analyses performed using both methods to show similar solutions, as well as to show similarity with the regions of seismic activity. The HGM2 in the HGM map and the ED5 in the ED map overlap in terms of length and position; in other words, the longest and most prominent lineaments show consistency in both methods. It is clear that Eskisehir Basin's tectonic evolution has been controlled by the HGM1-2 and ED2-4-5 since they appear as major tectonic elements in the study area (Figure 7). Therefore, one can conclude that the faults in the study area have played a key role in forming the upper crustal geometry. It was observed that earthquakes, to a large extent, cluster between lineaments HGM1 and HGM2, as per the HGM map. In addition, there was at least one earthquake over Mw 3.0 magnitude near the HGM3 and near the HGM4. Figure 7: (**a**) The HGM map and Mw 3.0 and above earthquake locations in the study area. (**b**) The Euler Deconvolution results and Mw 3.0 and above earthquake locations in the study area (da-tum: WGS4 UTM Zone 36 N).