Seismic structure across the rift valley of the Mid-Atlantic Ridge at 23°20′ (MARK area): Implications for crustal accretion processes at slow spreading ridges

Journal of Geophysical Research: Solid Earth

Volumn 105, Issue B12, 2000, Pages 28411-28425

  Canales, J Pablo ^a   Collins, John A ^a   Escartín, Javier ^b,c   Detrick, Robert S ^a  

^a WOODS HOLE OCEANOGRAPHIC INSTITUTION   (United States)

^b INSTITUTE OF EARTH SCIENCES JAUME ALMERA   (Spain)

^c SORBONNE UNIVERSITÉ   (France)

Author keywords

[No Author keywords available]

Indexed keywords

ACCRETION; MID-OCEAN RIDGE; RIFT ZONE; SEISMIC VELOCITY; SPREADING CENTER; VELOCITY STRUCTURE;

ATLANTIC OCEAN; MID-ATLANTIC RIDGE;

EID: 0034478453     PISSN: 21699313     EISSN: 21699356     Source Type: Journal    
DOI: 10.1029/2000jb900301     Document Type: Article

References (77)

1. Allerton, S., J. Escartín, and R.C. Searle, Extremely asymmetric magmatic accretion of oceanic crust at the end of slow-spreading ridge segments, Geology, 28, 179-182, 2000.
2. Ballu, V., J. Dubois, C. Deplus, M. Diament, and S. Bonvalot, Crustal structure of the Mid-Atlantic Ridge south of the Kane fracture zone from seafloor and sea surface gravity data, J. Geophys. Res., 103, 2615-2631, 1998.
3. Barclay, A.H., D.R. Toomey, and S.C. Solomon, Seismic structure and crustal magmatism at the Mid-Atlantic Ridge, 35°N, J. Geophys. Res., 103, 17,827-17,844, 1998.
4. Bonatti, E., Serpentinite protrusions in the oceanic crust, Earth Planet. Sci. Lett., 32, 107-113, 1976.
5. Brown, J.R., and J.A. Karson, Variations in axial processes on the Mid-Atlantic Ridge: The median valley of the MARK area, Mar. Geophys. Res., 10, 109-138, 1988.
6. Bryan, W.B., S.E. Humphris, G. Thompson, and J.F. Casey, Comparative volcanology of small axial eruptive centers in the MARK area, J. Geophys. Res., 99, 2973-2984, 1994.
7. Calvert, A.J., Seismic evidence for a magma chamber beneath the slow-spreading Mid-Atlantic Ridge, Nature, 377, 410-414, 1995.
8. Calvert, A.J., Backscattered coherent noise and seismic reflection imaging of the oceanic crust: An example from the rift valley of the Mid-Atlantic Ridge at 23°N, J. Geophys. Res., 102, 5119-5133, 1997.
9. Campbell, A.C., et al., Chemistry of hot springs on the Mid-Atlantic Ridge, Nature, 335, 514-519, 1988.
10. Canales, J.P., R.S. Detrick, J. Lin, J.A. Collins, and D.R. Toomey, Crustal and upper mantle seismic structure beneath the rift mountains and across a nontransform offset at the Mid-Atlantic Ridge (35°N), J. Geophys. Res., 105, 2699-2719, 2000.
11. Cann, J.R., D.K. Blackman, D.K. Smith, E. McAllister, B. Janssen, S. Mello, E. Avgerinos, A.R. Pascoe, and J. Escartín, Corrugated slip surfaces formed at ridge-transform intersections on the Mid-Atlantic Ridge, Nature, 385, 329-332, 1997.
12. Cannat, M., Emplacement of mantle rocks in the seafloor at mid-ocean ridges, J. Geophys. Res., 98, 4163-4172, 1993.
13. Cannat, M., et al., Proceedings of the Ocean Drilling Program, Initial Reports, vol. 153, Ocean Drill. Program, College Station, Tex., 1995a.
14. Cannat, M., et al., Thin crust, ultramafic exposures, and rugged faulting patterns at the Mid-Atlantic Ridge (22°-24°N), Geology, 23, 49-52, 1995b.
15. Christensen, N.I., Ophiolites, seismic velocities and oceanic crustal structure, Tectonophysics, 47, 131-157, 1978.
16. Christensen, N.I., Compressional wave velocities in rocks at high temperatures and pressures, critical thermal gradients, and crustal low-velocity zones, J. Geophys. Res., 84, 6849-6857, 1979.
17. Collins, J.A., and R.S. Detrick, Seismic structure of the Atlantis fracture zone megamullion, a serpentinized ultramafic massif, EoS Trans. AGU, 79(45), Fall Meet. Suppl., F800, 1998.
18. Coogan, L.A., P.D. Kempton, A.D. Saunders, and M.J. Norry, Melt aggregation within the crust beneath the Mid-Atlantic Ridge: Evidence from plagioclase and clinopyroxene major and trace element compositions, Earth Planet. Sci. Lett., 176, 245-257, 2000.
19. Crawford, W.C., S.C. Webb, and J. Hildebrand, Constraints on melt in the lower crust and Moho at the East Pacific Rise, 9°48′N, using seafloor compliance measurements, J. Geophys. Res., 104, 2923-2939, 1999.
20. Detrick, R.S., et al., Proceedings of the Ocean Drilling Program, Initial Reports, vol. 106/109, Ocean Drill. Program, College Station, Tex., 1988.
21. Detrick, R.S., J.C. Mutter, P. Buhl, and I.I. Kim, No evidence from multichannel reflection data for a crustal magma chamber in the MARK area on the Mid-Atlantic Ridge, Nature, 347, 61-64, 1990.
22. Detrick, R., J. Collins, R. Stephen, and S. Swift, In situ evidence for the nature of the seismic layer 2/3 boundary in oceanic crust, Nature, 370, 288-290, 1994.
23. Detrick, R.S., H.D. Needham, and V. Renard, Gravity anomalies and crustal thickness variations along the Mid-Atlantic Ridge between 33°N and 40°N, J. Geophys. Res., 100, 3767-3787, 1995.
24. Dick, H.J.B., G. Thompson, and W.B. Bryan, Low-angle faulting and steady-state emplacement of plutonic rocks at ridge-transform intersections, EoS Trans. AGU, 62, 406, 1981.
25. Donnelly, K.E., C.H. Langmuir, S.L. Goldstein, and D. Desonie, Systematic distribution of E-MORB in the MARK area, Eos Trans. AGU, 80(46), Fall Meet. Suppl., F1086, 1999.
26. Dunn, R.A., D.R. Toomey, and S. Solomon, Three-dimensional seismic structure and physical properties of the crust and shallow mantle beneath the East Pacific Rise at 9°30′N, J. Geophys. Res., 105, 23,463-23,478, 2000.
27. Faul, U.H., D.R. Toomey, and H.S. Waff, Intergranular basaltic melt is distributed in thin, elongated inclusions, Geophys. Res. Lett., 21, 29-32, 1994.
28. Gente, P., C. Mével, J.M. Auzende, J.A. Karson, and Y. Fouquet, An example of a recent accretion on the Mid-Atlantic Ridge: The Snake Pit neovolcanic ridge (MARK area, 23°22′N), Tectonophysics, 190, 1-29, 1991.
29. Gente, P., R.A. Pockalny, C. Durand, C. Deplus, M. Maia, G. Ceuleneer, C. Mével, M. Cannat, and C. Laverne, Characteristics and evolution of the segmentation of the Mid-Atlantic Ridge between 20°N and 24°N during the last 10 million years, Earth Planet. Sci. Lett., 129, 55-71, 1995.
30. Henstock, T.J., A.W. Woods, and R.S. White, The accretion of oceanic crust by episodic sill intrusion, J. Geophys. Res., 98, 4143-4161, 1993.
31. Hooft, E.E.E., R.S. Detrick, D.R. Toomey, J.A. Collins, and J. Lin, Crustal thickness and structure along three contrasting spreading segments of the Mid-Atlantic Ridge, 33.5°-35°N, J. Geophys. Res., 105, 8205-8226, 2000.
32. Hussenoeder, S.A., J.A. Collins, G.M. Kent, R.S. Detrick, and the TERA Group, Seismic analysis of the axial magma chamber reflector along the southern East Pacific Rise from conventional reflection profiling, J. Geophys. Res., 101, 22,087-22,105, 1996.
33. Karato, S., Importance of anelasticity in the interpretation of seismic tomography, Geophys. Res. Lett., 20, 1623-1626, 1993.
34. Karato, S., and H.A. Spetzler, Defect microdynamics in minerals and solid-state mechanisms of seismic wave attenuation and velocity dispersion in the mantle, Rev. Geophys., 28, 399-421, 1990.
35. Karson, J.A., Seafloor spreading on the Mid-Atlantic Ridge: Implications for the structure of ophiolites and oceanic lithosphere produced in slow-spreading environments, in Proceedings of the Symposium "Troodos 1987", edited by J. Malpas et al., pp. 547-555, Geol. Surv. Dept., Nicosia, Cyprus, 1990.
36. Karson, J.A., and J.R. Brown, Geological setting of the Snake Pit hydrothermal site: An active vent field on the Mid-Atlantic Ridge, Mar. Geophys. Res., 10, 91-107, 1988.
37. Karson, J.A., and H.J.B. Dick, Tectonics of ridge-transform intersection at the Kane Fracture Zone, Mar. Geophys. Res., 6, 51-98, 1983.
38. Karson, J.A., et al., Along-axis variations in seafloor spreading in the MARK area, Nature, 328, 681-685, 1987.
39. Kempner, W.C., and J.F. Gettrust, Ophiolites, synthetic seismograms, and ocean crustal structure, 2, A comparison of synthetic seismograms of the Samail Ophiolite, Oman, and the ROSE refraction data from the East Pacific Rise, J. Geophys. Res., 87, 8463-8476, 1982.
40. Kong, L.S.L., R.S. Detrick, P.J. Fox, L.A. Mayer, and W.B.F. Ryan, The morphology and tectonics of the MARK area from Sea Beam and Sea MARC I observations (Mid-Atlantic Ridge 23°N), Mar. Geophys. Res., 10, 59-90, 1988.
41. Korenaga, J., W.S. Holbrook, G.M. Kent, P.B. Kelemen, R.S. Detrick, H.-C. Larsen, J.R. Hopper, and T. Dahl-Jensen, Crustal structure of the southeast Greenland margin from joint refraction and reflection seismic tomography, J. Geophys. Res., 105, 21,591-21,614, 2000.
42. Lagabrielle, Y., D. Bideau, M. Cannat, J.A. Karson, and C. Mével, Ultramafic-mafic plutonic rock suites exposed along the Mid-Atlantic ridge (10°N-30°N): Symmetrical-asymmetrical distribution and implications for seafloor spreading processes, in Faulting and Magmatism at Mid-Ocean Ridges, Geophys. Monogr. Ser., vol. 106, edited by W.R. Buck et al., pp. 153-176, AGU, Washington, D. C., 1998.
43. Lin, J., G.M. Purdy, H. Schouten, J.-C. Sempéré, and C. Zervas, Evidence from gravity data for focused magmatic accretion along the Mid-Atlantic Ridge, Nature, 344, 627-632, 1990.
44. MacGregor, L.M., S. Constable, and M. Sinha, The RAMESSES experiment, III, Controlled-source electromagnetic sounding of the Reykjanes Ridge at 57°45′N, Geophys. J. Int., 135, 773-789, 1998.
45. Magde, L.S., A.H. Barclay, D.R. Toomey, R.S. Detrick, and J.A. Collins, Crustal magma plumbing within a segment of the Mid-Atlantic Ridge, 35°N, Earth Planet. Sci. Lett., 175, 55-67, 2000.
46. Maia, M., and P. Gente, Three-dimensional gravity and bathymetry analysis of the Mid-Atlantic Ridge between 20°N and 24°N: Flow geometry and temporal evolution of the segmentation, J. Geophys. Res., 103, 951-974, 1998.
47. Mainprice, D., Modelling the anisotropic seismic properties of partially molten rocks found at mid-ocean ridges, Tectonophysics, 279, 161-179, 1997.
48. Matarese, J.R., Nonlinear travel time tomography, Ph.D. thesis, 367 pp., Mass. Inst. of Technol., Cambridge, 1993.
49. Mével, C., M. Cannat, P. Gente, E. Marion, J.M. Auzende, and J.A. Karson, Emplacement of deep crustal and mantle rocks on the west median valley wall of the MARK area (MAR, 23°N), Tectonophysics, 190, 31-53, 1991.
50. Miller, D.J., and N.I. Christensen, Seismic velocities of lower crustal and upper mantle rocks from the slow spreading Mid-Atlantic Ridge, south of the Kane transform zone (MARK), Proc. Ocean Drill. Program, Sci. Results, 153, 437-454, 1997.
51. Morris, E., and R.S. Detrick, Three-dimensional analysis of gravity anomalies in the MARK area, Mid-Atlantic Ridge 23°N, J. Geophys. Res., 96, 4355-4366, 1991.
52. Mutter, J.C., and J.A. Karson, Structural processes at slow-spreading ridges, Science, 257, 627-634, 1992.
53. Navin, D.A., C. Pierce, and M.C. Sinha, The RAMESSES experiment, II, Evidence for accumulated melt beneath a slow spreading ridge from wide-angle refraction and multichannel reflection seismic profiles, Geophys. J. Int., 135, 746-772, 1998.
54. Ocean Drilling Program (ODP) Leg 106 Scientific Party, Drilling the Snake Pit hydrothermal sulfide deposit on the Mid-Atlantic Ridge, lat 23°22′N, Geology, 14, 1004-1007, 1986.
55. Pariso, J. E., J.-C. Sempéré, and C. Rommeveaux, Temporal and spatial variations in crustal accretion along the Mid-Atlantic Ridge (29°-31°31′N) over the last 10 Myr: Implications from a three-dimensional gravity study, J. Geophys. Res., 100, 17,781-17,794, 1995.
56. Pockalny, R.A., R.S. Detrick, and P.J. Fox, Morphology and tectonics of the Kane transform from Sea Beam bathymetry data, J. Geophys. Res., 93, 3179-3193, 1988.
57. Pockalny, R.A., A. Smith, and P. Gente, Spatial and temporal variability of crustal magnetization of a slow spreading ridge: Mid-Atlantic Ridge (20°-24°N), Mar. Geophys. Res., 17, 301-320, 1995.
58. Purdy, G.M., and R.S. Detrick, Crustal structure of the Mid-Atlantic ridge at 23°N from seismic refraction studies, J. Geophys. Res., 91, 3739-3762, 1986.
59. Salisbury, M.H., and N.I. Christensen, The seismic velocity structure of a traverse through the Bay of Islands ophiolite complex, Newfoundland, an exposure of oceanic crust and upper mantle, J. Geophys. Res., 83, 805-817, 1978.
60. Schulz. N.J., R.S. Detrick, and S.P. Miller, Two- and three-dimensional inversions of magnetic anomalies in the MARK area (Mid-Atlantic Ridge 23°N), Mar. Geophys. Res., 10, 41-57, 1988.
61. Sinton, J.M., and R.S. Detrick, Mid-ocean ridge magma chambers, J. Geophys. Res., 97, 197-216, 1992.
62. Smith, D.K., S.E. Humphris, and W.B. Bryan, A comparison of volcanic edifices at the Reykjanes Ridge and the Mid-Atlantic Ridge at 24°-30°N, J. Geophys. Res., 100, 22,485-22,498, 1995.
63. Sturm, M.E., S.J. Goldstein, E.M. Klein, J.A. Karson, and M.T. Murrell, Uranium-series age constraints on lavas from the axial valley of the Mid-Atlantic Ridge, MARK area, Earth Planet. Sci. Lett., 181, 61-70, 2000.
64. Tarantola, A., Inverse problem theory: methods for data fitting and model parameter estimation, 613 pp., Elsevier, New York, 1987.
65. Thompson, G., W.B. Bryan, and S.E. Humphris, Geochemical variations in basalts erupted in the MARK area, Mid-Atlantic Ridge 23°N, Eos Trans. AGU, 67, 1213.
66. Toomey, D.R., G.M. Purdy, and S.C. Solomon, Microearthquakes beneath the median valley of the Mid-Atlantic Ridge near 23°N: Tomography and tectonics, J. Geophys. Res., 93, 9093-9112, 1988.
67. Toomey, D.R., S.C. Solomon, and G.M. Purdy, Tomographic imaging of the shallow crustal structure of the East Pacific Rise at 9°30′N, J. Geophys. Res., 99, 24,135-24,157, 1994.
68. Tucholke, B. E., and J. Lin, A geological model for the structure of ridge segments in slow spreading ocean crust, J. Geophys. Res., 99, 11,937-11,958, 1994.
69. Tucholke, B.E., J. Lin, M.C. Kleinrock, M.A. Tivey, T.B. Reed, J. Goff, and G.E. Jaroslow, Segmentation and crustal structure of the western Mid-Atlantic Ridge flank, 25°25′-27°10′ and 0-29 m.y., J. Geophys. Res., 102, 10,203-10,223, 1997.
70. Tucholke, B.E., J. Lin, and M.C. Kleinrock, Megamullions and mullion structure defining oceanic metamorphic core complexes on the Mid-Atlantic Ridge, J. Geophys. Res., 103, 9857-9866, 1998.
71. Vera, E.E., J.C. Mutter, P. Buhl, J.A. Orcutt, A.J. Harding, M.E. Kappus, R.S Detrick, and T.M. Brocher, The structure of 0- to 0.2-m.y.-old oceanic crust at 9°N on the East Pacific Rise from expanded spread profiles, J. Geophys. Res., 95, 15,529-15,556, 1990.
72. Wessel, P., and W.H.F. Smith, New version of the generic mapping tools released, Eos Trans. AGU, 76, 329, 1995.
73. White, R.S., D. McKenzie, and R.K. O'Nions, Oceanic crustal thickness from seismic measurements and rare earth element inversions, J. Geophys. Res., 97, 19,683-19,715, 1992.
74. Wilkens, R.H., G.J. Fryer, and J. Karsten, Evolution of porosity and seismic structure of upper oceanic crust: Importance of aspect ratios, J. Geophys. Res., 96, 17,981-17,995, 1991.
75. Zelt, C.A., and D.A. Forsyth, Modeling wide-angle seismic data for crustal structure: Southeastern Grenville Province, J. Geophys. Res., 99, 11,687-11,704, 1994.
76. Zhang, J., and M.N. Toksöz, Nonlinear refraction traveltime tomography, Geophysics, 63, 1726-1737, 1998.
77. Zhang, J., U.S. ten Brink, and M.N. Toksöz, Nonlinear refraction and reflection travel time tomography, J. Geophys. Res., 103, 29,743-29,757, 1998.