* Scree is a collection of loose rock fragments at the base of a cliff or slope.

* Talus is a similar term, often used interchangeably with scree, though it may sometimes refer to a larger, more extensive accumulation of rock debris.

Why does this happen?

* Weathering: The rocks on the mountain are constantly being broken down by weather (rain, frost, wind, etc.).

* Gravity: As the rocks break down, they become loose and are pulled downhill by gravity.

* Foot Traffic: When you walk on a mountain path, your steps can dislodge loose rocks, contributing to the scree.

It's important to be aware of scree when hiking:

* Be careful: Scree can be slippery and unstable, making it easy to lose your footing.

* Look for stable paths: Try to stay on established paths to minimize your impact on the environment.

* Use caution on steep slopes: Steeper slopes are more prone to scree.

Let me know if you have any other questions about hiking or geology!