Grikes form as solution widens joints or cleavage planes. As the defects concentrate the flow, the water produces even more pronounced grikes. Grikes may develop up to 2 meters in depth. These features form in bare, partly-covered, or completely covered karstic rocks. In bare karst, the grikes are visible on the surface. In partly covered karst, these features may contain soil or humus in the bottom. In covered karst, the grikes are filled with soil or humus.
Grikes can also form along bedding planes and then the name bedding grikes is used.