1. Melt Properties

2. Updates/questions? Labs: Field trip:18 th or 19 th ? Last lecture’s 3 remaining slides in lab Today’s topics: 1.Magma properties

3. Melt properties - Internal variables

4. Composition Majority of Earth’s minerals are …? Bill White’s Geochemistry book

5. Silicates http://visionlearning.com/library/modules/mid140/Image/VLObject-3539- 060516120522.jpg

6. Networks http://visionlearning.com/library/modules/mid140/Image/VLObject-3539- 060516120522.jpg

7. Bridging Oxygen www.uwgb.edu/dutchs/PETROLGY/NesoSoro.HTM http://visionlearning.com/library/modules/mid140/Imag e/VLObject-3539-060516120522.jpg

8. NBO/T NBO/T change with melt composition….why? Mysen, 1983 RhyoliteBasalt

9. Structure in Melt Carmichael et al., 1974

10. Breaking the polymers Carmichael et al., 1974 www.origins.rpi.edu/claycatalyzed.html

11. Effect of volatiles

12. Polymerization and Viscosity What will move more easily: a)Shorter chain polymers? b)3D networks? What does that mean w.r.t. rock types?

13. Viscosity

14. http://video.google.com/videosearch?ndsp=18&um=1&hl=en&client=firefox-a&rls=org.mozilla:en-US:official&q=viscosity&ie=UTF-8& sa=N&tab=iv#ndsp=18&um=1&hl=en&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&q=viscosity&ie=UTF-8&sa=N&tab=iv&start=10

15. Viscosity

16. Viscosity, composition, temperature Scarfe., 1986 Decreasing SiO 2

17. Viscosity and pressure Scarfe., 1986

18. Viscosity and H 2 O Scarfe., 1986

19. Lava types and viscosity USGS Ctein

20. Viscosity regimes Regimes related to temperature w.r.t. Tg T >> Tg Viscosity very low, follows power law:  (T) =  o (T-T c ) -   ~2, T c = critical T (> Tg) T ~ Tg Intermediate viscosity, follows exponential:  (T) = A e exp(B e /(TS conf )) Ae~0.003, S from experiments, B e from fit T << Tg: Very high viscosity: sample turned into glass (Bottinga et al., 1995)

21. Rheology and time Webb & Dingwell, 1995

22. Glass Transition