2. 1; movies

3. Topography of a fast spreading ridge (EPR)

4. Topography of a slow spreading ridge (south atlantic)

5. 2; topography

7. Melt beneath a fast-spreading ridge (East Pacific Rise)

8. Ophiolites

9. 3; classic ophiolites

10. Oman ophiolite

11. Pillow lavas

12. Sheeted Dikes

13. Layered Gabbros

14. V s is the particles' settling velocity (vertically downwards if ρ p > ρ f, upwards if ρ p < ρ f ) g is the acceleration due to gravity, ρ p is the density of the particles, and ρ f is the density of the fluid Stokes law

15. 4; settling

16. Massive gabbro

17. Impregnated dunnite Banded harzburgite

19. Hot spot volcanism: a global phenomenon

20. 5; Hawaii-emperor chain

21. The origin of hot spot volcanoes from melting of plumes

22. Dynamic models of mantle convection Plates going down Plumes coming up Rapid, small-cell convection on Io

23. Why does the mantle melt to produce hot spot magmas? Isentropic decompression melting Fluxing by volatiles Heating of the lithosphere by a hot plume Unconventional heat sources

24. Simple variations on the decompression melting theme Variations in potential temperature -- hotter mantle produces deeper melting, more magma Variations in the thickness of the lithosphere -- controls the depth at which melting terminates Fractional vs. batch melting All of these can vary from hot spot to hot spot and within a single volcano, producing distinctive chemical signatures

26. Temperature variations near head of plume 3D Model by Ribe and Christensen

27. Why does the mantle melt to produce hot spot magmas? Isentropic decompression melting Fluxing by volatiles Heating of the lithosphere by a hot plume Unconventional heat sources

28. Why does the mantle melt to produce hot spot magmas? Isentropic decompression melting Fluxing by volatiles Heating of the lithosphere by a hot plume Unconventional heat sources

29. Hawaii (topography/bathymetry)

30. Geological map of the big island of Hawaii

32. HSDP drilling in 1993 and 1999 into the flank of Mauna Kea volcano >95% recovery, to a total depth of 3.1 km below sea level Penetration through ~1 km of subaerial lavas, ~2 km of submarine deposits, both hyaloclastites and pillows

33. estimate of average subsidence rate

35. hyaloclastite formation -- “prograding delta” volcano growth

37. Trace elements and isotopic ratios are generally correlated with variations in SiO 2 content (Kurz et al, 2003)

38. What if the length scales of compositional heterogeneities are small?