Molten rock when Earth Science is childs play! EarthCache
Molten rock when Earth Science is childs play!
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This is a great way to learn some Earth science while the kids play! You will need a ruler with you!
The state of Maine is covered by rocks that have come from elsewhere - brought by glaciers, and in this case, by humans. But the lesson here is not about the transport of this rock, but what you can see within it.
Look for the rock with the very obvious black stripe. It really stands out!
The bulk of this rock is a white granite, which formed from molten rock deep in the the Earth's crust. This molten rock cooled slowly and formed quite large crystals of quartz, feldspar and mica. After millions of years of cooling the rock was thrust up towards the surface.
Sometime after the rock was a cold white granite, another type of molten rock which was not rich in molten quartz, was squeezed up into the granite, moving along natural cracks and crevices. When the molten rock touched the cold granite it cooled quickly, forming tiny crystals which are impossible to see without a microscope. Further towards the center of the crack that the molten rock filled, the dark molten material cooled a little slower, so that some minerals were able to form bigger crystals. Finally the molten rock completely cooled, locking in those crystals and forming a vein of the rock we call basalt.
To log this EarthCache, please email us (using the caching name above) answers to the following questions:
1. Using a ruler, how wide across is this vein of basalt?
2. How far from the side of the vein can you start to see crystals in the basalt?
3. How large are the crystals you can find in the basalt?
We would love to see a picture of you at the site (this is optional)...and also love to know how many people were with you when you visited this EarthCache.
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