2. Massonne et al., (1999)

4. Diamond bearing inclusions in garnet (after Stöckhert et al., 2001)

5. After Massonne et al. (1999), Stöckhert et al. (2001)

6. Geodynamic environment

7. Krohe (1996) Franke (1989)

9. Zulauf (1997) Subduction Subduction+Collision Collision Delamination+detachment+underplating

10. Exhumation of high-pressure rocks during delamination+detachment+underplating stage

11. Numerical modeling: Schott & Schmeling (1998), Willner et al. (2002)

12. Depth=200 km Willner et al. (2002) Formation and destruction of deep crustal wedge during detachment of the lithosphere Depth=150 km Depth=100 km

13. Question: how and whether subduction->collision->detachment sequence of events might be genetically related to origin of the diamond bearing rocks? Method: numerical geodynamic modeling

14. 1600 x 600 km 370 x 200km 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1400 o C Weak zone Lithosphere Asthenosphere 1600 o C Mantle plume upwelling Slab push Slab pull 1400 o C Continental crust Oceanic crust Sediments Serpentinized mantle Hydrated zone Rock samples Antigorite stability field Hydration front Numerical model (full convection solution) High resolution region

15. Animation “Typical evolution”

16. 0.00 Myr 890 x 470 km 370 x 200km 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Initial configuration

17. 0.21 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

18. 0.68 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

19. 1.4 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

20. 2.1 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

21. 3.1 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

22. 4.6 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

23. 7.7 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

24. 11.3 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

25. 15.0 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

26. 18.9 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

27. 22.7 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

28. 25.3 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

29. 26.2 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Subduction

30. 27.0 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Collision

31. 27.7 Myr 400 o C 800 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Collision ~160 km (bottom of the lithosphere) 1200 o C ~160 km

32. 28.3 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Collision, Delamination Slab delamination

33. 28.9 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Collision, Delamination, Necking Slab delamination Slab necking

34. 29.4 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Collision, Necking Slab necking

35. 29.8 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating Mantle underplating

36. 30.3 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating Mantle underplating

37. 30.7 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating Mantle underplating

38. 30.9 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating

39. 31.2 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating

40. 31.5 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating

41. 31.8 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating, Domal structures Domal structure growth

42. 32.1 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating, Domal structures Domal structures growth

43. 32.4 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating, Domal structures Domal structures growth

44. 32.6 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating, Domal structures Domal structures growth

45. 32.9 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating, Domal structures Domal structures growth

46. 33.3 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating, Domal structures Domal structures growth

47. 33.6 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating, Domal structures Domal structures growth

48. 34.1 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating, Domal structures Domal structures growth

49. 36.4 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating, Domal structures Domal structures growth

50. 37.5 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C Extension, Detachment, Underplating, Domal structures Domal structures growth

51. 39.6 Myr 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C The End Domal structures growth

52. 200 o C 400 o C 600 o C 800 o C 1000 o C ~160 km (bottom of the lithosphere) Stoeckhert et al. (2001) Cooling stage

53. “Heating+Cooling during subduction” Gerya & Stoeckhert (2002) Active margin B BEGIN

54. Isobaric cooling 19.3 Myr 1000 o C 200 o C 800 o C 400 o C 1200 o C 600 o C Stoeckhert et al. (2001) Cooling stage ~100 km (bottom of the lithosphere)

55. What does slab break-off look like? ? ?

56. Animation “Slow necking”

57. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 5.0 Myr Collision

58. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 5.8 Myr Collision

59. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 6.6 Myr Collision + Delamination

60. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 7.3 Myr Collision + Delamination

61. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 8.0 Myr Collision + Delamination

62. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 8.7 Myr Collision + Delamination

63. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 9.3 Myr Collision + Delamination

64. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 10.0 Myr Collision + Delamination

65. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 10.7 Myr Collision + Delamination

66. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 11.4 Myr Delamination

67. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 12.1 Myr Delamination

68. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 12.8 Myr Delamination

69. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 13.4 Myr Delamination

70. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 14.0 Myr Detachment

71. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 14.6 Myr Detachment

72. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 15.2 Myr Detachment

73. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 15.7 Myr Detachment

74. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 16.3 Myr Detachment

75. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 16.9 Myr Detachment

76. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 17.5 Myr End

77. Animation “Rapid necking”

78. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 30.6 Myr Collision

79. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 31.3 Myr Collision

80. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 32.3 Myr Collision

81. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 33.1 Myr Detachment

82. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 34.1 Myr Extension + Underplating

83. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 34.8 Myr Extension + Underplating

84. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 35.4 Myr Extension + Underplating

85. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 35.9 Myr Extension + Underplating

86. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 36.3 Myr Extension + Underplating

87. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 36.7 Myr Extension + Underplating

88. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 37.0 Myr Extension + Underplating

89. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 37.3 Myr Extension + Underplating

90. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 37.6 Myr Extension + Underplating

91. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 38.0 Myr Extension + Underplating

92. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 38.4 Myr Extension + Underplating

93. 400 o C 800 o C 1200 o C 200 o C 400 o C 600 o C 800 o C 1000 o C 1200 o C 38.8 Myr End

94. Symmetric necking (no preexisting weak zone) Assymmetric necking by shearing along preexisting weak zone But is this really “break-off”?

95. 33 Myr 28 Myr 30 Myr 29 Myr