Rocks and energy

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Rocks and energy

April 2011

+Igneous Rocks

• Igneous Rocks were the original rocks formed while the Earth cooled.

• When a rock is melted and allowed to cool, it becomes an igneous rock.

+Igneous Rocks

• Magma: found in the mantle. Lava under the crust. • Lava: liquid rock that is found on top of the crust. Lava comes

out of a volcano. • There are 2 types of Igneous Rock:

1. Extrusive: this igneous rock is found above the crust and cools quickly producing small rocks.

2. Intrusive: this igneous rock is found underground and cools very slowly, producing large rocks. Example : Granite.

• The most common rocks found in the Earth’s crust.

+Igneous rocks

+Characteristics of Igneous Rocks

Felsic: is a type of magma that is Al based and are lighter in color. Much lower density.

Mafic: is a type of magma Fe and Mg based and are darker in color.

+

Sedimentary rock

Chapter 6 April 2011

+Sedimentary rock

Sediments: pieces of solid material that have been deposited on Earth’s surface by wind, water, ice, gravity, or chemical precipitation.

When sediments come together they form sedimentary rocks. This begins with either weathering or erosion.

+Examples of sedimentary rock

+Shale- Natural gas

+Deposition

• Sediment ends up being deposited once transport stops.

• Remember, faster moving water or wind can transport larger particles.

• So, naturally larger pieces will slow down first, followed by smaller pieces.

• Some transporters carry all sediments equally like landslides and glaciers.

+The Deposition cycle

+Lithification

• Sediments deposited in sedimentary basins.• This build up causes increasing temperature and

pressure in an area which leads to LITHIFICATION.

• THIS IS WHAT MAKES SEDIMENTS COMBINE TO FORM SEDIMENTARY ROCKS!

• Cementation refers to when mineral growth cements sediment grain together into solid rocks.

+Cementation

+Features of sedimentary rock

• Bedding ( horizontal layering)• Graded bedding (particle size become heavier and

courser towards the bottom layers) Marine sedimentary rock

• Cross bedding: inclined layers of sediment move forward across a horizontal surface.

+Energy from rocks and Minerals?

1. Carbon: Mineral: Oil, Petroleum, Coal

2. Natural Gas: Sedimentary Rock: Shale

3. Nuclear Power: Uranium and Plutonium

Which is best?

+Features of sedimentary rock

+Metamorphic rock

• Pressure and temperature increases with depth….when temperature or pressure increases: rocks melt and form magma.

• If the rocks do not melt, they are still capable of being distorted

• Various types of Metamorphic Rocks• Regional metamorphism• Contact metamorphism• Hydrothermal metamorphism

+Metamorphic rock

+Regional metamorphic

+Contact metamorphic

+Hydrothermal metamorphism