1. Melting Regions of the Mantle Terry Plank: LDEO with C-T. Lee (Rice) D. Forsyth (Brown) E. Hauri (Carnegie ) K.Fischer (Brown) G. Abers (LDEO) D.Wiens (Wash U)

2. Boundary Layers and Melting b.holtzman 2009 Boundary layer dynamics drive melting melt extraction creates lithosphere

3. East Pacific Rise MELT Experiment Forysth et al (1998) Japan Volcanic Arc P-wave tomography Zhao et al (1992)

4. What does RED mean? 1.Hot ? 2.Wet? 3.Melt ? from Yang and Forsyth, 2006, JGR Southern California shear velocity anomaly (70-90 km depth)

6. 0 1 2 3 11001200130014001500 Temperature (°C) Pressure (GPa) Melt Thermobarometers dry solidus Solidus from Hirschmann (2000) olivine-melt thermometer MgO ol MgO liq D = = f (T) 40 km 70 100 +/- 30 °C

7. 0 1 2 3 11001200130014001500 Temperature (°C) Pressure (GPa) Melt Thermobarometers dry solidus Solidus from Hirschmann (2000) olivine-melt thermometer silica-melt baromometer MgO ol MgO liq D = = f (T) Mg 2 SiO 4 ol + SiO 2 liq = Mg 2 Si 2 O 6 opx a(SiO 2 ) liq ~ 1/K Thermobarometer parameterizations from C-T Lee et al, EPSL, 2009 40 km 70 100 +/- 0.2 GPa +/- 30 °C

8. 0 1 2 3 11001200130014001500 Temperature (°C) Pressure (GPa) Melt Thermobarometers dry solidus Solidus from Hirschmann (2000) olivine-melt thermometer silica-melt baromometer MgO ol MgO liq D = = f (T) Mg 2 SiO 4 ol + SiO 2 liq = Mg 2 Si 2 O 6 opx Thermobarometer parameterizations from C-T Lee et al, EPSL, 2009 4.5 wt% H 2 O 40 km 70 100 a(SiO 2 ) liq ~ 1/K

9. For H 2 O, we need melt inclusions in olivine from well-quenched tephra

10. Benjamin, Plank, Wade, Hauri & Alvarado (JVGR, 2007)

11. 1. East Pacific Rise 3. Central American Arc 4. Basin and Range Examples of Melting Regions 2. Back-arc Basins

12. 1.East Pacific Rise (MELT and GLIMPSE) Ridge Harmon, Forsyth, Weeraratne (EPSL, 2009) Shear velocity model

13. 0 1 2 3 4 110012001300140015001600 Temperature (°C) Pressure (GPa) oceanic crust Pacific off-axis Nazca off axis on-axis 80 km 50 km 110 km 15 km P-T calculated from thermobaromters in Lee et al (EPSL, 2009): Fo 90, 100% Fe 2+ ; H 2 O = 0.1 wt% Most MORB data from Sinton et al (JGR, 1991) and Hall et al (G3, 2006); all > 8.2 wt% MgO method in LKP92 and Wiens et al (2006) 100 ppm H 2 O

14. Ridge Harmon, Forsyth, Weeraratne (EPSL, 2009) Shear velocity model dry solidus magmas solidus with 100 ppm H 2 O T p = 1470°C

15. 050100 0 40 80 120 km 130014001500 01020 Harmon, Forsyth, Weeraratne (EPSL, 2009) Shear velocity model Ridge dry solidus magmas solidus with 100 ppm H 2 O Temperature (°C) ppm H 2 O % Melting km T p = 1470°C Wet melting model after Langmuir et al (2006)

16. From Conder et al (JGR, 2002) test dynamic models

17. 0 50 100 150 200 3.8 4.0 4.2 4.4 4.64.8 Shear velocity (km/s) Depth (km) Model that satisfies Q = 80; T p = 1350°C derived from Rayleigh waves melt? …or Tp = 1450°C After Yang & Forsyth (EPSL, 2007)

18. 2. Back-arc Basins Wiens, Kelley & Plank (EPSL, 2006)

19. S wave velocity (km/s) N. Lau & N. Fiji Mariana Tr. & Scotia Wiens, Kelley & Plank (EPSL, 2006) (dry melts only) MELT

20. Wiens, Kelley & Plank (EPSL, 2006) S.EPR (MELT)? Temperature variations on Vs

21. 3. Volcanic Arc Rychert, Fisher, Abers, Plank, Syracuse, Protti, Gonzalez, Strauch (G3, 2008) Syracuse, Abers, Fischer, MacKenzie, Rychert, Protti, Gonzalez, Strauch (G3, 2008)

23. Rychert, Fisher, Abers, Plank, Syracuse, Protti, Gonzalez, Strauch (G3, 2008)

25. Olivine-liquidus depression due to water from Medard and Grove (2007))

26. US Array: Transportable Array

27. from Deuker et al, 2001, JGR from Yang and Forsyth, 2006, JGR LV = Long Valley BP = Big Pine GT = Golden Trout C = Coso 70-90 km depth

28. Lathrop Wells volcano 70,000 yrs old 18 km south of Yucca Mnt Yucca Mnt

29. Wang, Plank, Walker and Smith, JGR, 2002 Mantle Melting Profile Across B&R dark green columns = + ε (Nd) (astheno.)

30. 120°W 118 116 114 112 0 km 50 100 150 Transect at 37°N Courtesy of Yingjie Yang ( Yang, Ritzwoller, Lin, Moschetti, Shapiro, JGR, in press )

31. 120°W 118 116 114 112 0 km 50 100 150 Transect at 37°N BP Courtesy of Yingjie Yang ( Yang, Ritzwoller, Lin, Moschetti, Shapiro, JGR, in press )

32. 120°W 118 116 114 112 0 km 50 100 150 Courtesy of Yingjie Yang ( Yang, Ritzwoller, Lin, Moschetti, Shapiro, JGR, in press ) Transect at 37°N BP LW SC 1200-1340°C 1.8 wt% H 2 O 1365-1390°C 3.2 wt% H 2 O 1445-1460°C 0.9 wt% H 2 O T p =1350 T p =1390 T p =1440

33. 1. East Pacific Rise 3. Central American Arc 4. Basin and Range Examples of Melting Regions 2. Back-arc Basins presence of melt mantle Tp variations effect of water on Q mapping T, melt and H 2 O