U-shaped valleys, trough or glacial troughs, are formed by the process of glaciation. They are characteristic of mountain particular. U shape, with steep, straight sides and a flat or rounded bottom (by contrast carved by rivers tend to be V-shaped in cross-section). Glaciated glacier travels across and down a slope, carving the valley by the action of scouring. When the ice recedes or thaws remains, often littered with small boulders that were transported within the called till erratic. Gully moraine. High altitude rocky mountains alpine meadow tundra topographic geology. Rize Turkey Kavrun Kackar. Aerial footage with drone. 4K UHD 3840×2160 30p.