Relief of the Chuy Valley
The main types and forms of relief in the region are the result of prolonged geological development of the territory, tectonics, combined with the complex composition of the lithology of rocks and the active participation of various physical-geographical processes. All of this has determined the complex diversity of the surface structure of the Chuy Valley and its mountainous framing.
On the geomorphological map included in the Atlas of the Kyrgyz SSR (1987), P.G. Grigorenko, along with other authors, identified types of relief grouped into three main genetic categories: tectonic-denudational mountainous, tectonic-denudational-accumulative foothill, and tectonic-accumulative plain.
In the Chuy Valley and its mountainous framing, the following relief complexes are clearly distinguished: mountain tectonic-denudational, foothill tectonic-denudational-accumulative, and plain tectonic-accumulative. Each complex represents a combination of types and forms of relief characterized by specific morphometric features and morphological signs, and differs in its economic significance.
The mountain complex is further divided into the following types of relief:
• Dissected glacial highlands;
• Dissected erosional mid-mountains;
• Erosional low mountains - foothill uplands.
The dissected glacial highlands occupy the axial parts and lateral ridges of the Kyrgyz Ala-Too at elevations of more than 3500-4000 m. The northern slopes of the Kyrgyz Ridge are divided into three unequal parts: central, eastern, and western, based on the nature of glaciation and orography (S. Maximov, A. Osmanov, 1995).
The external contours of the relief are sharp, with steep slopes and sharp rocky peaks. Along the northern slope of the ridge, a continuous chain of cirques can be observed - huge bowl-shaped depressions formed by glaciers, measuring up to 400 m, sometimes more than 600 m in diameter. They are often multi-chambered and contain glaciers. Frequently, as the back walls of opposing slopes converge, the cirques form a saddle in the watershed ridge, or when the walls of three or four cirques converge in the middle, a rocky peak remains - Karling.
Traces of past Quaternary glaciation, in the form of cirques, trough valleys, morainic dammed lakes, and terminal moraines, are observed in several places of the Kyrgyz Ridge. For example, from the ends of modern glaciers in the upper reaches of the rivers Shamsy, Issyk-Ata, Ala-Archa, Ak-Suu, etc., trade valleys begin with steep slopes and flat bottoms. The depth of the troughs is usually 150-200 m. In their lower parts, the troughs are to some extent disrupted by post-glacial erosion. Troughs are box-shaped valleys that have partially lost their original features.
At the lower end of the troughs, there is also a pile of moraines forming significant height steps. Among the morainic formations, terminal moraines hold a special place. They usually represent irregularly bulging elevations, stones - "heads," rising several tens of meters above the valley level. Often, terminal moraines are associated with ridge-like steps.
Dammed lakes formed by terminal moraines are also found, which were described by S. Maximov and A. Osmanov (1995).
The dissected mid-mountains are widely distributed in the Kyrgyz Ala-Too and occupy altitudinal limits of 2100-3200 m. In the central and western parts of the ridge, they directly adjoin the highland relief, while in the eastern part, they are represented by more or less independent mountain masses (Oktorok, Baibichenin Soorus, Kok-Jon, Gagyzgan-Choku, etc.). The mid-mountains are characterized by more rounded, soft contours, but at the same time, they are intensely dissected by a network of grand canyons, reaching depths of up to 500-700 m or more. The areas of maximum height of the mid-mountains, represented in the central part of the ridge, are distinguished by the greatest depth of dissection.
The considered relief, depending on the nature of geological structure and relief, is divided into two subtypes:
• Mid-mountains on a loose Paleogene-Neogene foundation. Developed in the interfluves of Shamsy - Kyzyl-Suu. The relief is generally uniform, valleys are relatively wide, interfluves are hilly, dissected by shallow ravines;
• Mid-mountains on a solid Paleozoic foundation. Characterized by a greater diversity of relief forms. The relief features denudational surfaces. The valleys of rivers are canyon-shaped, their slopes are steep, often rocky.
