1. IGNEOUS ROCKS

2. Igneous rocks: Latin = ‘fire’
form when molten rock cools and solidifies (crystallizes) into different minerals from
magma - Underground.Cools slowly
- Solidifies at 700 – 1250o Celsius
lava - erupted at Earth's surface. Cools rapidly

3. Texture The properties and sizes of the various crystals determined by magma's :
rate of cooling, and
composition

4. composed of large crystals, Texture = coarse grained
Classification of Igneous rocks :
Intrusive rocks (or plutonic rocks) - form by slow cooling of magma underground
composed of large crystals, Texture = coarse grained
crystals had a long time to grow- are large

5. 2. Extrusive rocks (or volcanic rocks) which form at Earth's surface from lava
Small crystals, or none at all
Cool very fast
Texture - fine-grained (aphanitic), - glassy

6. Felsic/ Mafic Rock
Felsic is less dense, lighter in color, usually has a lot of silicon
Mafic is dense, darker color, usually has a lot of iron

7. Granite, Igneous, intrusive, coarse grained, light colored

9. Gabbro is a dark-colored coarse-grained intrusive igneous rock.

10. Plutonic rock exposed by weathering

11. Pumice is a light-colored , felsic, igneous rock
Pumice is a light-colored , felsic, igneous rock. It forms through very rapid cooling of lava. The pores are a result of gas trapped in the lava at the time of solidification.

12. Scoria is a dark-colored, extrusive, igneous rock.

13. Obsidian - igneous rock
Obsidian - igneous rock. Forms when molten rock material cools so rapidly that atoms are unable to arrange themselves into a crystalline structure. Get a volcanic glass with a smooth uniform texture that breaks with a conchoidal fracture Aphanitic

14. Igneous glassy texture

17. Basalt is a dark-colored, fine-grained, igneous extrusive rock composed mainly of plagioclase and pyroxene minerals

18. Igneous Porphyritic texture

19. Intrusive Rock Formation
Plutons – large balloon-shaped formations
Batholiths – Huge underground formations
Both are made up of Plutonic Rock

20. Extrusive Rock Formations
Remnants of volcanoes or Fissures
Dike, Sill, Volcanic neck
Solidified lava flows -
Rock that FLOATS!! Full of volcanic gas

21. Summary
All igneous rock was once molten!

22. Classification of Igneous Rocks
Extrusive or Intrusive
Fine-grained or Coarse–grained
Fast-forming and Slow-forming
Mafic or Felsic

23. Igneous Rock names to Know
Basalt Granite Pumice Scoria
Obsidian
Basalt
Rhyolite
Gabbro

24. Bonifacio, Corsica Photograph by Marc Dozier, Corbis Perched atop 200-foot chalk cliffs, the town of Bonifacio lights up the southern tip of Corsica. The French island is an eruption of granite and magma just 56 miles west of Italy. Its craggy mountains soar to almost 9,000 feet on one coast, while undulating beaches and vineyards line the other.

26. Homework 
Wksht.
Quiz - tba