Monday, September 15, 2014

Blog Entry 1
Topic: Earth's Innards(Basic Rock Types)

In Arvada Colorado, there is a place known as "Katelyn's Backyard." In Katelyn's Backyard there are many things to observe. Such as the river, rocks, hills/fields, and trees. In my backyard there are many rocks that i had never really given much thought to until now. I found Igneous, Sedimentary, and Metamorphic rocks right in my backyard.

Igneous: Rocks formed from the solidification of molten rock material.
Igneous rocks are formed when magma in the earth gets trapped. When this trapped magma cools it forms little pockets that turn into igneous rocks. These rocks can also be formed from volcanic eruptions above the surface. 



The picture of the left is an example of a extrusive igneous rock. The little holes in the rock are formed when gas is trapped within the rock before it solidifies.


















This is a granite igneous rock. It is a light colored rock, and contains feldspar minerals and quartz. It is a rock you have to observe closely to see all its pieces.















Sedimentary: Rocks formed from the accumulation of sediments.
Sedimentary rocks are formed when sediments of other rocks start to form together. The 4 steps for this process are: erosion, transportation, deposition, and finally when the rock is compacted. Once everything is squashed together after this process, you know have a sedimentary rock. These rocks cover 3/4 of the earth's surface. 





This is an example of a conglomerate sedimentary rock. These rocks contain large and small particles that all have formed together. The smaller particles of the rock holds it together.















Metamorphic: Rocks that have been modified by heat, pressure,  and chemical processes.
Metamorphic rocks are formed from other rocks when heat and pressure affect them. These rocks them combine and are known as metamorphic rocks. 



This rock is slate, this rock is composed during the metamorphism of shale. Slate also splits into thin pieces, and you can easily see an example of this to the right of the rock in this picture where is looks like a thinner layer on top.

Sources:
http://geology.com/rocks/igneous-rocks.shtml
http://geology.com/rocks/sedimentary-rocks.shtml
http://geology.com/rocks/metamorphic-rocks.shtml
http://www.universetoday.com/82009/how-are-igneous-rocks-formed/
http://www.sciencedaily.com/articles/s/sedimentary_rock.htm
http://www.bbc.co.uk/bitesize/ks3/science/environment_earth_universe/rock_cycle/revision/5/