1. Dr. Jeff Amato Geological Sciences Rocks Igneous Rocks

2. Themes for today: (1) Heat and the Earth (2) Melting processes (3) Differentiation (4) Igneous rock classification (5) Plate tectonics and igneous rocks

3. How do we know the Earth is hot?

4. Why is the Earth hot inside?

5. (1) Early collisions create heat. Planetesimals Protostar Planetesimal ~1 km

6. (2) Radioactive decay creates heat

7. Geothermal Gradient Rate of T increase with depth

8. Why is the Earth hot on the SURFACE?

9. 90%

10. 10%

11. What controls heat loss? Radiation Conduction Convection

12. Themes for today: (1) Heat and the Earth (2) Melting processes (3) Differentiation (4) Igneous rock classification (5) Plate tectonics and igneous rocks

13. How to form magma: 1) Raise the temperature 2) Lower the pressure 3) Add water

14. Phase Diagram for Water

15. Melting dry rocks

17. Melting wet rocks

19. How to form magma: 1) Raise the temperature: CRUSTAL MELTING 2) Lower the pressure: DECOMPRESSION MELTING 3) Add water: HYDRATION MELTING

20. Themes for today: (1) Heat and the Earth (2) Melting processes (3) Differentiation (4) Igneous rock classification (5) Plate tectonics and igneous rocks

21. Igneous Rock Classification Ultramafic Mafic Intermediate Felsic

22. From Ultramafic to Felsic…. Fe, Mg, Ca decreases Density decreases SiO 2 increases K, Na increases