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Rocky Valley..... EarthCache

Hidden : 6/25/2018
Difficulty:
1.5 out of 5
Terrain:
1.5 out of 5

Size: Size:   other (other)

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Geocache Description:


Up at the listed co-ordinates is a rugged valley, hidden from sight from the town below. It is known as Rocky Valley, but you are not going to find:

Image result for rocky and​       or Image result for Rocky and Bullwinkle

At first sight you may think that the location is the site of an old quarry, but there is something much more ancient and brutal about this place. To the south of the path you are stood on,you will notice a shattered landscape of massive angular boulders here, which lie below the steep escarpment of the cliffs up above. To the north of the path, you will notice a rising hummocky ridge.


So what has happened here?

The geology of the moor is made up of sandstones, and shales , laid down in layers known as strata during the Carboniferous period. Later on during the quatenary period, the moor was covered by an ice sheet. The sub zero temperatures, caused the ground and underlying rocks to be deeply frozen, in a state of permafrost. As the ice sheet retreated, and the environmental temperature warmed, so did the rocks. As the shale warmed, the melting permafrost led it to develop into a clayey soil, due to a higher water content compared with the sandstone. This water saturated shale, then developed into a situation where the strata above no longer had a stable base. Imagine if you stood on ice, with flat shoe soles, you like the sandstone above the shale can potentially become unstable. 

On a flat level landscape, this would not play much of a problem, but add another dimension then the whole situation becames much more unstable. That other dimension is the hilly location, which means that there is potential for the sandstone above the shale to start moving, and cause a landslide, this is made much more likley as the angle of the slope increases.

An ancient landslide has occured here, in quite a dramatic fashion, the shale having become a slip plane. 


There are different forms of landslides:

Rock falls

​These happen when blocks of rock fall off a cliff and outcrops and fall down a slope.

Block slides 

This is where blocks of soil or rock move down a slope. Imagine a geocache ammunition box sliding down a ramp, it sides will maintain intact, in the case of a body of soil or rock, the sides are straight after it has moved down the inclined slip place.

Slumps

​In this case, the slip plane is concave, this means that the landslipe rotates and tilts objects so that they point up hill. 

Creep

This is a slow inperceptible movement of a landmass, it may not be at first apparent, but over time, sloping posts, trees and subtle movement of rocks may become apparent.


The whole of the hillside to the immediate north west of the Rocky Valley has an hummocky appearance, this is a remenant of the landslide.


This being an EarthCache, in order to log it, I ask that you answer some questions. Please send them to me, and do not include them in your log. You can send them to me by using the message facility or email, both of which can be found by looking at my profile.

1. From the listed co-ordinates walk down the path towards Stage 2. Please look at the debris field to the south of the path. What type of landslide process has taken place here? What is the rationale for your answer?

2. At Stage 2. Look at the outcrop of rocks at the western end of the hummocky ridge. By looking at the way that the rocks are positioned, what landslide process has taken place? What is your rationale for this answer?

3. What angle do the rocks at stage 2 sit at in degrees?

Additional Hints (No hints available.)