Mussera Upland (Abkhazia) as an Example of the Mountain Region Transition Zone: Typical and Specific Features

A geomorphological description of the Mussera upland, located in the northwestern part of Abkhazia, was carried out based on the results of fieldwork. It is an alluvial-proluvial-colluvial upland, dissected by numerous erosion forms to the state of badland. We have shown its typical features for the transition zones of the foothills and the specifics of the structure and development of the topography due to the climatic conditions. The lower parts of the Mussera molasse, composing the upland, contain mainly limestones, and the upper ones contain igneous and metamorphic rocks of the core of the Caucasus and terrigenous rocks. This indicates that the upland was formed by being involved in the uplift of the adjacent monocline ridges of the southern slope of the Greater Caucasus, when the erosion reached the basement rocks. The conducted spore-pollen analysis allows us to conclude that the formation of the upland and its constituent molasses began at the Paleogene-Neogene boundary and continued until the Pleistocene. The beginning of the active dissection of the upland probably dates back to the Neogene–Eopleistocene boundary and continues to this day. Thus, the study confirms the traditional ideas about the neotectonic uplift of the Caucasian. Petrographic and spore-pollen diagrams based on samples of the Mussera molasse, a morphostructural and general geomorphological map of the Mussera upland area, and its morphometric characteristics are presented.

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