1. Plates vs. Plumes: A Geological Controversy Gillian R. Foulger Durham University, U.K.

2. 2 Morgan (1971) The Plume Hypothesis

3. 3

4. 4 The Plate hypothesis

5. Top Down vs. Bottom Up

6. 6 Predictions of the Plume Hypothesis

8. 8 Burov (2005) 1. Precursory uplift

9. 9 Coffin & Eldholm (1993) 2. Flood basalt eruption

10. 10 Campbell (2005) 3. Plume “tail” to the core-mantle boundary

11. 11 Hawaii 4. Time-progressive chain

12. 12 5. High temperature

13. 13 Predictions of the Plate Hypothesis

14. 14 1. Lithospheric extension 2. Source fusibility 3. Shallow mantle source

15. 15 Plume predictions are not confirmed

16. Precursory uplift

17. Emeishan basalts, China – 260 Ma

19. ? Ukstins-Peate & Bryan, Nature Geoscience, 2009 Campbell, Elements, 2005

20. Time-progressive volcanic chains

21. 21 Hawaii 80 Ma 50 Ma 0 Ma

22. 22

23. Seismology – looking for plume tails

24. Seismic imaging is a can of worms Hmm… Is this a multi-headed plume?

25. Bruce map

26. Hawaii: Tomography Li et al. (2008) Wolfe et al. (2009) NW SE

27. Cao et al. (2011) 2000 km WE Hawaii: Receiver functions

29. No-one can agree on how many plumes there are, or where they are

30. Many “hot spot” lists

31. 31 Tholeiitic provinces Ritsema & Allen (2003) Courtillot et al. (2003) Montelli et al. (2006)

32. 32 Flood basalt & volcanic chain: only 3/49! None fit all the predictions

33. Endless plume variants Lateral flow of plume material Tabular plumes Pulsing plumes High 3 He/ 4 He plumes Low 3 He/ 4 He plumes Headless plumes Tailless plumes 33

34. 34 Comparison with geosynclines Mio-geosyncline Eu-geosyncline Ortho-geosyncline Primary geosyncline Zeugo-geosyncline Para-geosyncline Exo-geosyncline Taphro-geosyncline Paralia-geosyncline

35. This is not scientific

36. 36 What about the Plate hypothesis?

37. 37 The Plate hypothesis involves diverse processes

38. 38 This immediately fits the observations

39. Examples

40. 40 Continental breakup Van Wijk et al. (2001); Jones (2005)

41. 41 Silver et al. (2006) Southern Africa Melt ponding & draining is required

42. European Intraplate Volcanism Tamar Graben?

43. ? ? ?

44. 44 Beutel (2005) Extensional stress at plate boundary junctions

45. 45

47. 47 Slab tearing at Samoa Samoa

49. A comment on boxing matches…

50. That’s all folks