Rolls or Canyons: How Valleys Form
In the process of landform development, valleys are a common feature that can be formed in various ways. One of the initial stages in the formation of valleys is the presence of rolls or canyons, which eventually develop into valleys over time.

Rolls
Rolls are gentle, undulating landforms that can be found in various landscapes. They are formed through the process of erosion and weathering, where softer rocks are worn down faster than harder rocks. As this erosion occurs, the landscape starts to take on a rolling appearance, with smooth, rounded hills and valleys.
Over time, these rolls can become more pronounced as erosion continues to shape the landscape. As water flows over the land, it follows the path of least resistance, carving out deeper channels between the rolls. This gradual process of erosion and deposition eventually leads to the formation of valleys.

Canyons
Canyons, on the other hand, are deep, narrow valleys with steep sides. They are typically formed through the process of erosion by rivers or glaciers. As water flows through the landscape, it cuts into the rock, creating deep channels that gradually widen over time.
Canyons can also be formed through tectonic activity, where the Earth's crust is uplifted or faulted, creating steep cliffs and valleys. In some cases, canyons are formed through a combination of erosion and tectonic activity, resulting in dramatic landscapes like the Grand Canyon in the United States.

Conclusion
In conclusion, valleys can start as rolls or canyons, depending on the geological processes at play in a particular landscape. Whether through the gradual erosion of rolls or the more dramatic formation of canyons, valleys are a crucial part of the Earth's diverse and dynamic landforms.