Crag and tail, also known as crag with tail, is a geological landform characterized by an elongated ridge or hill composed of sturdy rock material, referred to as a crag, and a tapering, elongated slope, referred to as a tail, extending downhill from the crag. This distinctive landform typically emerges as a result of glacial erosion.
The crag, or steep rocky cliff, is usually formed from resilient and more resistant rock types that are capable of withstanding the erosive forces of glaciers. As a glacier advances over the landscape, it carves and abrades the surrounding softer rock, leaving behind the prominent crag as a remnant of the more resistant material that was less easily eroded. The crag often highlights the previous geological layers of the landscape, displaying the structure and composition of the underlying rocks.
The tail, on the other hand, is composed of glacially deposited material, such as gravel, sand, and till, which is pushed and distributed downhill as a glacier retreats. This material accumulates as a ridge-like formation that tapers away from the crag and is often smoothed or rounded due to glacial action.
Crag and tail formations are common in glaciated regions and are particularly prevalent in areas where the direction of ice flow was oriented from the crag towards the tail. The contrasting characteristics of the crag and the tail provide evidence of the geological processes that shaped the land during the presence and retreat of glaciers, making them significant features for geologists and researchers studying glacial landscapes.
