Baba Mountain consists primarily of granites and crystalline schists, featuring characteristic glacial landforms and stone rivers that bear witness to an ancient geological evolution.
The geological structure of Baba Mountain, a typical horst, consists predominantly of Paleozoic schists and granites, exposed in the central part through tectonic and erosional processes. The main ridge begins in the north with the peak Kozji Kamen (2,137 m) and extends into Greece. Side ridges branch off to the east and west, separated by river valleys. This main mountain ridge also serves as the drainage divide between the Adriatic and Aegean basins.
Among the morphosculptural elements, the ‘stone rivers’ (blockfields) located at altitudes between 1,300 and 2,000 meters are particularly prominent, standing out as some of the most distinctive on the Balkan Peninsula. Alluvial fans are another significant relief feature, appearing in a long belt along the eastern, northern, and western foothills. During the Pleistocene, the high-mountain parts of Baba were subject to glaciation, leaving traces in the current relief in the form of fossil glacial features: cirques and moraines.
Within the expanded area of NP Pelister, the largest surface area is occupied by Paleozoic schist rocks. These possess a diverse lithological composition, including a series of quartz-sericite and green schists, as well as a phyllitoid series. In addition, a significant area is covered by granitoid rocks of Paleozoic age. These granites form the magmatic core of Baba Mountain as a massive magmatic body—a batholith.
Paleorelief Landforms
According to previous research, traces of early valleys and fluvio-denudational planation surfaces are found in the northern area of Baba Mountain. Particularly characteristic are the surfaces associated with the fossil epigenetic Djavat Valley. Epigenetic features are also distinguished in the valley of the Shemnica River, followed by the Caparska and Rotinska Rivers. Furthermore, of geomorphological interest is the extensive undulating planation surface stretching along the eastern foothills between the villages of Lavci and Bukovo.
Neorelief Landforms
In the area of NP Pelister, fluvial, glacial, periglacial, and denudational features dominate among post-Neogene relief forms. Within the National Park, river valleys, together with mountain ridges and crests, represent the most prominent morphological element. Due to intense tectonic movements on one hand, and the lowering of Lake Prespa and the disappearance of the Pelagonian Lake on the other, river valleys are deeply incised between mountain ridges. The valleys follow two characteristic trends: meridional and sublatitudinal. Because of tectonic pre-dimensioning and their connection to the lower lake base level, major mountain rivers are deeply incised with very steep valley slopes. As a result of this steep incision, river terraces are usually poorly expressed along the valley sides.