## 2 Geological Settings
Aluvial sediments can be found in the area along the Danube. As a rule, deeper parts of the Danube alluvium are built of gravel and sand. The central part is predominantly built  
Figure 2: Geological map with unstable slopes. of sands with thin layers of silty sediments and mud, while the surface is predominantly built of silty sediments and, to a lesser extent, silty-sandy and muddy sediments. Igneous rocks also participate in the structure of Fruska Gora. The following varieties are represented: trachytes, latites, altered peridotites, volcanic tuffs, dacito-andesites, melafirs, diabases, and gabbro. They appear in the form of intrusive penetration, in the form of wires, concordant breakthroughs, and volcanic outbursts. Igneous rocks are of the Paleozoic, Triassic, Cretaceous, and Tertiary ages. In neotectonic terms, Fruska Gora is a typical horn incurred with the relative rise along the system of longitudinal faults, running in the east-west direction. In the earlier tectonic stages, this basic structural form was subsequently separated into smaller blocks of various shapes and sizes by transverse and diagonal faults. According to the analysis of satellite imagery, the most important structures are dozens of kilometers long. These are complex structures of different genesis, geometry, and kinematics (fault zones, stepped faults, large individual faults). A much smaller number of faults run north-south or in other directions. These are short, one-kilometer-long faults. These shorter fault structures are younger, most likely of the Neogenic age [16]. Quantitative geomorphological analysis--based on the relief's energy and the relief's deviations from the theoretical model and its development in time--has confirmed the findings that individual blocks along the faults are moving relatively upward or relatively downward. In this respect, the east-west-oriented faults are of essential importance. Based on detailed explorations of some tunnel walls excavated in the mountain in flysch sediments of the Upper Cretaceous, trachites, and serpentinites, we found that they contain a number of faults and fault zones. Rock masses are intensely fractured in the fault zone. The fact is that neotectonic activities have been continuously unfolding to this day. We are still lacking sufficiently precise data and measurements that would explain this complex topic. For the amount and nature of neotectonic movement to be more reliably identified, it is necessary to conduct precise geodetic measurements. In the example of detailed landslide examinations in the area of the Sloboda bridge in Novi Sad, it was confirmed that neotectonic activities do not affect the formation of deep landslides. The Fruska Gora area is not endangered by very strong earthquakes. Referring back to the period of 50 years, the central area of the mountain belonged to 7\({}^{\circ}\) MCS. Referring back to the period of 100-500 years, Fruska Gora belonged to 8\({}^{\circ}\) MCS [12]. It should be noted that despite the area's relatively favorable seismicity, some microlocations and important buildings require seismic microzonation, thereby correcting the basic degree. The Examples of Several Most Significant Deep Landslides along the Danube on the Fruska Gora Slopes  
Deep landslides of this type are the largest and the most important on the northern slopes of Fruska Gora. They emerged on the right valley side of the Danube, from Nestin to Smederevo [17; 18; 19], almost continuously nearly 100 km in length. In some sections of the aforementioned area, the sliding process is particularly emphasized from Nestin to Susek, from Banostor to Cerevic, western part of Sremska Kamenica and Bocke, from Sremska Kamenica to the Petrovaradin fortress [16; 20], Puckaros, Bovine, the eastern part of Sremski Karlovci, Sremski Karlovci-Cortanovci-Beska, etc.