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Rocks ain't Rocks EarthCache

Hidden : 5/6/2017
Difficulty:
2.5 out of 5
Terrain:
2 out of 5

Size: Size:   other (other)

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Geocache Description:


This is an EarthCache and has special requirements for logging it.  You cannot log a Found It without responding to the logging requirements set out below. 

Only one find claim per Message. Each Geocacher claiming a find must submit an individual response. One team can not lodge a response on behalf of a group of people.


Hopefully, after visiting this site, you will have an expanded appreciation of the wonders of our natural environment, and recognise that the environment here has a rather rare geological feature.


A good few of us can probably all recall the Castrol advertising campaign “Oils Ain’t Oils” with Sol and his gangster friends – designed to introduce the motorist to ‘man made’ synthetic oils. Oils are not the only focus of manipulative mankind - read on.

The earth's landscape is always changing, but the changes happen so slowly that they are difficult to see. Forces such as heat and pressure change the landscape through weathering and erosion. It can take thousands of years for rocks to change shape through erosion, and millions for one rock type to transform into another.

The rocks that form Earth’s crust are continually destroyed and remade in an endless process called the rock cycle. Rock is formed from magma (molten rock); by cooling and solidifying; by changing through heat and pressure; and by compression and cementation of rock fragments caused by weathering and erosion.

From this description, you can figure out that there are three basic types of rock, in order of description: igneous, metamorphic and sedimentary.  Of course, there are many sub-classifications of rocks - that's where geology really becomes interesting (and can be quite complex!).

Granite rocks can be very old. Some granite, in Australia, is believed to be more than four billion years old, although when rocks get that old, they've been altered enough by geological forces that it's hard to classify them.

When I was a youngster, I had an early Saturday morning job sweeping and rolling some tennis courts in preparation for the day's amateur matches.  The "decomposed granite" used for the surface came from the granite quarries (now defunct) along Settlement Road, The Gap.  The granite rocks there fit the description in the previous paragraph.  Forces of nature had broken down the tough granite of millions of years ago into something that could be crushed and used, for example, in the tennis courts I helped prepare.

Part A.

Look at the rocks at 'Ground Zero' (you are standing on the concrete pathway, facing up the hill):

  1. Identify these rocks as either igneous, metamorphic, or sedimentary.
  2. Give a very short justification for your answer
  3. Feel the rock surface of the closest rock, and describe its texture

Part B.

Take ten paces up the hill directly from where you were standing at GZ.

  1. Describe the 'rocks' you see here (in simple terms, please)
  2. Feel the rock surface, and describe its texture. Is it different to your answer to question three above?
  3. What tell-tale signs are there that what you are seeing is not natural
  4. There are more formations like this one. Why do you think they are here?

Part C

Take of photo of yourself OR your GPS to show a view of GZ.  Include it in your message, but please do not post it in your log, it might give too much away.

"Oils Ain’t Oils" and "Rocks Ain't Rocks"!. Not better. Not different. Just made to serve a different purpose.

 

When you have your responses to the questions above, please MESSAGE them to the CO. I don't deal with email very well. I will contact you once I read your MESSAGE. But you can log your find in the meantime, and just say that you have MESSAGED your answers to the CO.

Happy Earthcaching!


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