Karst is a landscape formed by the destruction of soluble rock. Karst forms are expressions of rock destruction by solution and erosion. This development starts at the moment when the soluble rock is exposed to meteoric water, when the rock contains groundwater. It is intensified when the rock is exposed to weathering and is no longer protected by covering layers of rocks. And it ends when the rock is completely eroded and disappears. The development of karst areas follows general rules that may differ by rock and climate, but have a common denominator.
When the rock is fractured by tectonic forces, groundwater can enter. Without a circulation, solution processes do not yet occur on a large scale. Nevertheless, the first foundations for karstification are already being formed. Drainage is still occurring above ground.
The outflow (the drainage of the area) deepens, in general caused by uplift and the erosion of valleys. Some of the drainage is underground and so erosion at the surface decreases, widening of fractures increases, and drainage shifts underground.
The karst area has the well-known karst phenomena, caves, sinkholes, dry valleys and so on. Drainage is (almost) entirely underground. The caves form floors that correlate with the level of the receiving water. Karst windows are formed, polje and first caves collapse.
As dissolution progresses, the ceilings of the caves become thinner and collapse. This results in the formation of valleys that represent former cave systems. In the age phase, the situation is thus reversed: instead of small sinkholes and polje in a limestone area, there are only islands of limestone separated by wide valleys and plains. This final phase is also characterized by particularly large cave systems in the remaining limestone areas. It is also referred to as cockpit or tower karst.