1. Objective: 1.Describe processes of rock formation.
2. Compare and contrast intrusive and extrusive igneous rocks.
3. Classify different types and textures of igneous rocks
4. Recognize the effects of cooling rates on the grain sizes of igneous rock
5. Describe some uses of igneous rocks

2. Rocks: Mineral Mixtures
(Elements) S6E5b & c.
S6E5b: Investigate the composition of rocks in terms of minerals
&
S6E5c: Classify rocks by their process of formation.

3. aturally occurring olid norganic ixed composition rystalline structure
What is a mineral?
olid
aturally occurring
norganic
SNIFC
ixed composition
rystalline structure

4. What is a ROCK Exactly? SNI olid aturally Occurring
s made up of minerals or organic matter.
SNI

5. ROCK
A naturally occurring solid mixture of one or more minerals or organic matter.

6. Texture
Is the size (course), shape (tiny like seeds), pattern (multicolored), and positions of the grains that make up the rock. A rocks texture is the look of the rock’s surface, determined by the size, shape, pattern, and position of the grains. (How it looks)

7. Grains gives the rock texture.
Grains-particles (pieces) of minerals or other rocks.
Grains gives the rock texture.
Siltstone Sandstone Conglomerate
Fine-grained Medium-grained Coarse-grained

8. COMPOSITION
The chemical makeup of a rock; describes either the minerals or other materials in the rock.
The combination of elements or compounds (minerals the rock is made up of) that make up a rock.

9. Rocks are composed of (made up of) two or more minerals.
What’s the difference?
Minerals have a
Definite chemical composition and a characteristic crystalline structure.
May be a single element such as copper (Cu) or gold (Au), or it
May be a compound made up of a number of elements.
Rocks are composed of (made up of) two or more minerals.

10. Compare Contrast mineral in terms of a rock
Difference
Fixed composition
Difference
How are they ALIKE
Naturally occurring
Solid
Organic matter

11. Classification System
Classified according to its color, texture and mineral composition. Using these characteristics a geologist can determine the rock’s origin or where and how it formed.

12. Origins of Igneous Rocks where they are formed
ex- means “out of” or “outside.”
In- means “within or into”;
Extrusive Rocks:
These rocks are formed above the ground when lava flows or explodes from a volcano.
Intrusive or plutonic igneous rock Rock: These rocks form underground from magma.
Granite
Basalt
Obsidian
Gabbro

13. Texture of Igneous Rocks
Texture depends on the size and shape of the crystals when the rock forms. This is due to the cooling rate of the rocks.
Slow Cooling: Slow cooling produces coarse grains with large crystals. This is associated with intrusive rocks.
Rapid Cooling: Rapid cooling produces fine grains and small crystals. This is associated with extrusive rocks.
Diorite
Andesite

14. Let’s pull it all together!
Small OR invisible grains
Large grains