이 응회암이 두껍게 쌓인 후 식으면서 발생한 부피 감소에 의해 절리가 많이 형성되었고, 그중 일부 절리는 벌어져 넓은 수직 틈이 생겼다.
After the tuff was thickly piled up, many joints were formed due to the decrease in volume that occurred as it cooled, and some joints opened to form wide vertical gaps.