IGNEOUS ROCKS

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Igneous rock begins as magma

What is the origin of Igneous Rock?

http://www.webquest.hawaii.edu/kahihi/sciencedictionary/images/magma_flow_up.gif

There are three ways magma can form:

1. when rock is heated,

2. when pressure is released,

3. when rock changes composition.

What are the ways that magma can form?

Put a drawing like this on pg 37 in your nb

The longer it takes for the magma or lava to cool, the more time mineral crystals have to grow.

The more time the crystals have to grow, the larger the crystals.

The larger the crystals are the coarser the texture of the resulting igneous rock is.

What happens

to magma when it cools at different

rates?

The less time magma takes to cool, the less time crystals have to grow. Therefore, the rock that is formed will be fine grained.

What happens

to magma when it cools at different

rates?

Fine-grained igneous rock contains very small crystals, or if the cooling is very rapid, it contains no crystals.

What happens

to magma when it cools at different

rates?

What are the Compositions and Textures

of Igneous Rock?

What are examples of each type?

What is Intrusive Igneous Rock?

Magma that cools and solidifies deep within the Earth’s crust.

What is Intrusive Igneous Rock?

Magma that intrudes, or pushes, into surrounding rock below the Earth’s surface and cools.

What is Intrusive Igneous Rock?

Usually has a coarse-grained texture because it is well insulated by surrounding rock and cools very slowly. The minerals that form are large, visible crystals.

What are the different

masses of intrusive

igneous rock named and

why?

Masses of intrusive igneous rock are named for their size and shape

PlutonsBatholithsStocks Dikes

Plutons are large, irregular-shaped intrusive bodies.

The largest of all igneous intrusions are batholiths.

Stocks are intrusive bodies that are exposed over smaller areas than batholiths.

Dikes sheetlike intrusions that cut across previous rock units.

Sills are sheetlike intrusions that are oriented parallel to previous rock units.

Plutons

Batholiths

Stocks

Dikes

Sills

PLUTONS

Where would I find

Extrusive Igneous Rock?

Magma that erupts, or extrudes, onto the Earth’s surface. Extrusive rock is common around volcanoes.

Lava cools quickly on the surface and contains very small crystals or no crystals.

What type of texture

do extrusive igneous

rock have?