This cache is a simple Earthcache and is part of my New Series of Caches called "Twelve Cache Types in a Day. I have placed one of each available cache type close together so that anyone can get Twelve Cache Types in a Day.
At Ground Zero you will be at the center of a Granite outcrop that is approximately 2km long by 5 meters wide. This Granite outcrop runs North / South and consists of granite pieces from a few centimeters to several feet across.
Granite is a kind of igneous rock, found on Earth but nowhere else in the Solar System. It is formed from hot, molten magma. Its color ranges from pink to grey.
There are three main ways that the Granite at Ground Zero could have become exposed to the surface so that you can now see it. These are Tectonic Movements (earthquakes), Volcanic Action, and/or Erosion:
1. Tectonic movements -- As the various plates that make up the Earth's surface move around, some crash into each other and one is forced up over the other. The rocks that were deep underground are forced up near the surface.
2. Volcanoes spew out lava which forms igneous rocks, but certain kinds of explosions will toss out large chunks of metamorphic rock from deep underground as well.
3. Erosion is primarily responsible for most of what we see as the surface of the Earth. While the other two actions will bring the rock near the surface, the action of wind and water removes the top layers of dirt and lighter rock.
Igneous Rocks How is Igneous Rock Formed?
These rocks are formed when magma cools and then goes solid. This might happen either above or below the surface.
• Magma can be forced into rocks, blown out in volcanic eruption or even forced to the surface as lava.
• The atoms and molecules of melted minerals is what make up magma.
• These atoms and molecules arrange themselves into mineral grains as the magma cools down, and this forms rock.
What types of Igneous Rocks are there? Rocks are categorised by the way that they form. Igneous Rocks from when magma cools and hardens, whether it is under the Earth or on the surface. The exact location of where the rock forms, determines what type of igneous rock it is. Get ready to find out about different igneous rocks.
Extrusive Igneous Rocks
When magma rises up to the surface of the Earth and then hardens, we get something called extrusive igneous rock. This type of rock is almost a bit glassy in texture as they form very, very quickly. Types of extrusive igneous rocks are pumice and basalt. Pumice is used in heaps of things like toothpaste, cement, and cosmetic products. Basalt however is used in buildings and statues. Sometimes extrusive rocks are called volcanic rocks as volcanoes are obviously very important in how they form. Extrusive Igneous Rocks are formed when magma rises to the surface of the Earth and hardens, which forms extrusive igneous rocks. Extrusive rocks like basalt are fine grained, is that as they cool quickly at the surface, the minerals don't have time to form large crystals so the resulting grain is fine.
Intrusive Igneous Rocks
Intrusive igneous rocks is granite. Intrusive igneous rocks, they are formed when the magma cools and hardens below the Earth’s surface. These rocks take a long, long time to form because of the way that they are made. They feel very grainy when you touch them. Granite is used for making gravestones, statues and countertops too. Do you have a granite countertop at home? It’s very durable, which means it can take a lot of pressure and wears very well. When intrusive rocks form huge bodies, like those found inside of mountains they are called Batholiths. The rocks that cool slowly beneath the earth have ideal conditions for the minerals to form large crystals, and that's why the grains in granite are are very coarse and you can see the individual large crystals.
Intrusive Igneous Rock Facts
• Ninety-five percent of the Earth's crust is made of igneous rock. Wow, that’s a lot.
• There are over 700 different kinds of igneous rocks that have been identified so far.
• The ocean floor is normally made out of basalt rock, which is hard and black, and an extrusive rock of course.
• The batholiths that we spoke about can be as large as about 97km across. That’s huge!
To Claim this Earthcache please email the answers to the following questions to DARKSIDEDAN. Do not post your answers in your "Found It" log.
Question One: At GZ What is the size of the biggest of Granite Boulder and why do you think the Granite has not eroded like other rocks around the GZ?
Question Two: What are the colors of the Granite boulders and describe the size of the grains in the boulders?
Question Three: Is the Rock at GZ an Extrusive Igneous Rock or Intrusive Igneous Rocks, How did you come to this conclusion?
Question Four: How much of the Earth's crust is made of Igneous Rock?
Please include a photo of you holding some granite at GZ (Optional, Not required to log this cache)