Talus slopes form as pieces of rock fall away from the bedrock of the cliff or hillside above. Usually the main mechanism that splits off these pieces of rock is ice or frost heaving. Water gets into small cracks and freezes, expanding and pushing the crack wider. Eventually the rock is wedged off falling down onto the pile of rocks below.
These rocks pile up to a maximum angle called the angle of repose, the same term used to describe the maximum angle a sand dune will achive. This angle is dependant upon the size of the grains.
The term scree slopes is also used to describe these landforms, but typically scree is used for rocks that are smaller than about 1 foot.
Logging requirements:
Send me a note with :
- The text "GC14ZQY Yellowstone Talus Slope" on the first line
- The number of people in your group.
- compare the shapes of the rocks in the talus slope and the ones near the coordinates, see if you can account for the difference
- Looking at the source of the talus, how many new pieces are getting ready to fall.
- According to the sign, how are the rocks moving and what is the movement compared to.
The above information was compiled from the following sources:
- NPS informational Pannel
- Scree - Wikipedia http://en.wikipedia.org/wiki/Scree.
Placement approved by the
Yellowstone National Park