dolini

A dolina is a type of surface depression that forms in karst terrain. Karst is a landscape formed from the dissolution of soluble rocks, such as limestone, dolomite, and gypsum. Dolines are typically funnel-shaped or bowl-shaped and can vary in size from a few meters to over a hundred meters in diameter and depth. They are a common feature in many karst regions around the world.

The formation of dolines is primarily due to the process of karstification. Water, particularly rainwater, is slightly acidic due to absorbed carbon dioxide from the atmosphere. As this acidic water percolates through the bedrock, it dissolves the soluble rock material, creating underground voids and conduits. Over time, these underground cavities can enlarge.

There are several ways a dolina can form. One common mechanism is suffosion, where finer sediment within the overlying soil or rock layers is washed down into underground fissures and cavities. This removal of material causes the surface above to collapse or subside, forming the depression. Another mechanism is collapse, where the roof of an underground cavity becomes too thin to support the weight of the overlying rock and soil, leading to a sudden collapse and the formation of a sinkhole. True dolines are often distinguished from sinkholes by their typically gentler slopes and the process of gradual subsidence rather than sudden collapse.

The presence of dolines is a key indicator of karst landscapes and can influence surface hydrology, as water often drains into these depressions and disappears underground. They can also pose challenges for infrastructure development and agriculture.