FORT GIBSON LAKE *ROCKS* EARTHCACHE
This is an earthcache which will hopefully provide you with an educational experience about a feature on our planet. There is no physical container for you to find. Your visit here will be a fact gathering trip to answer the questions below. You do not have to climb the Rock to complete this cache.
In this lesson we are going to learn how to identify some of the most common rocks. First, What is a rock? A rock is a solid natural occurring aggregate.
A rock can fall under one of three classes or types which are Igneous, Metamorphic, and Sedimentary.
All three major types of rocks can be made into the other type. Rocks have to be eroded to form sediments by wind, water, and ice. Now all those sediments are buried and in time it becomes sedimentary rocks. If they get buried very deep they become metamorphic rocks due to heat and pressure. And if they melt they become Magma. And when the Magma cools it becomes igneous rocks. These process take millions of years.
Igneous
Igneous rock is formed through the cooling and solidification of magma or lava. Igneous rock may form with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Intrusive Rocks:
Granite : light in color with large interlocking crystals. Gabro : dark in color with large interlocking Crystas. Both of these types are very hard to break.
Extrusive Rocks:
Basalt: dark in color with small crystals Tuff : deposited ash that cools to form Both are hard to break.
Scoria : Lava that cool fast and the bubbles forms the holes. Easy to break.
Metamorphic Rocks
The are rocks that have been squeezed and heated but not melted. Now the new rock depends on what the original rock was and the amount of heat and the pressure it received.
Examples: Gneiss and Quartzite are very hard to break. While slate is very easy to brake. On marble can see the veins and crystals.
Sedimentary Rocks
These are the types of rocks that are formed by the deposition of materials within bodies of water.
Limestone : Made from coral, calcite, and shells. Sometimes you can see small pieces of corals or animal shells.
Sandstone : Made from sand, grains of sand can be seen.
Shale : Made from mud and it may contain fossils
To log your visit to this EC e-mail me the following answers to the following questions:
1. Earthcache name and GC number
2. At posted cords you will see a rock wall where the road was cut through. In your best estimate what is the size of this rock that is exposed?
3. What type of rock is at the present location?
4. What is this rock made of?
5. What is the color of this rock?
6. Photos are optional, but please don't post photos showing the answers.
This is a public parking area.