To start lets define what is a Valley?
A valley is a depressed area of land between mountains or hills. If you look at a map of KZN, you'll see it is a perfect location to study this natural land formation. Valleys often have rivers flowing through them, just as the tributary of the Town Bush Stream runs directly below you at GZ (you would probably have had to cross it to get to GZ from the parking). Now we are going to explain the difference between just 2 of the valley types V-shaped and U-shaped.
V-Shaped Valleys:
A valley with a river flowing through it is usually V-shaped. The steepness of the sides will usually depend on the size of the river and the speed that the river flows as well as the type of rock the river is flowing over, for example a narrow river that flows very fast over a sandstone floor will most likely erode the landscape a lot faster and would end up with either a canyon / gorge / a very steep sided valley while a very wide slow flowing river that is flowing over a granite floor will most likely be very shallow and the sides of the valley will most likely be very gentle as the river will probably be depositing more than eroding, If the rock was softer you would probably end up with a U-shaped valley.
U-Shaped Valleys:
Valleys can have a wider U shape than the V-shaped valley mentioned above. For example a river high up between two close mountains will create a V, but when that same river flows downhill to sea level, it snakes across the landscape (meanders is the term commonly used), creating a wider valley.
Think of a field where people often walk, 1) if it is wide people walk all over and the area takes a long time to wear-out the grass (this is the same as U-shaped valleys), if it is narrow people walk in single file and people tread on the same path over and over, wearing it down more quickly (this is very much like V-shaped valleys).
There are other shaped valleys if you would like to research them, here are a few:
- Tunnel valleys
- Melt-water valleys
- Hanging valleys
Then there are the very unique Rift Valleys which are formed by the expansion of the Earth's crust due to tectonic activity beneath the Earth's surface but that we will cover in another earth cache.
Questions:
1) Looking at the view of the Chase Valley in front of you, what type of valley shape would you say it is?
2) (Proof of visit to GZ) - There is a Boulder that has been broken in a very specific way behind the bench at GZ, how was it broken and why do you say so?
3) (Optional) - Take a Photo from GZ of something that you found interesting or beautiful and include it with your log.
Hope you enjoyed this Earthcache and enjoyed the views over the valley below while taking a breather on the bench built at GZ.
Please send your answers to us via geocaching.com messaging system or email us via our profile
References:
http://study.com/
https://en.wikipedia.org
HTH Goes to Lost Landie and Mills 369 who were with me when I decided to place this EC