2. What kinds of rock does Colorado have?

3. How are each of the 3 types of rocks formed? SedimentaryIgneousMetamorphic From fragments of other rock that have been weathered, eroded, and deposited. Compaction and Cementatation Chemical: from precipitation Organic: from dead plants and animals By melting from extreme heat. Intrusive: cools slowly underground, crystals have a long time to grow and are big. Extrusive: cools quickly above ground, crystals have less tome to grow and are small. Heat and Pressure. Contact metamorphism: rocks come in contact with hot magma but do not melt Regional metamorphism: Large regions of land collide, exerting great pressure on the rock or pushing them deep underground Foliation: bands of rock formed by extreme pressure

4. How were the Rockies created?  They were created by folding of the Earth’s crust when the Pacific and North American plates collided.  They were shaped by erosion caused by glaciers, running water, and wind.  http://channel.nationalgeographic.com/series/naked- science/3347/Videos#tab-Videos/05056_00 http://channel.nationalgeographic.com/series/naked- science/3347/Videos#tab-Videos/05056_00

5. How do you account for all of the metamorphic rock at the Earth’s surface?  It was pushed to the surface when the Pacific plate scraped under the North American plate.  The rock on top of it was eroded away to expose the granite.

6. How do you account for all the Igneous rock in Southern Colorado?  La Garita was a volcano that exploded 29-40 million years ago.  It was 50 times bigger than the largest nuclear bomb ever produced.  The explosion laid down ash all over the Western US