Assessing the conditions of continental breakup at magma-poor rifted margins: What can we learn from slow spreading mid-ocean ridges?

Abbate, 1980, Apennine ophiolite. A peculiar oceanic crust, Ofioliti, 1, 59 Allen, 2004, Serpentinization and heat generation: Constraints from Lost City and rainbow hydrothermal systems, Geochim. Cosmochim. Acta, 68, 1347, 10.1016/j.gca.2003.09.003 Andreani, 2007, Dynamic control on serpentine crystallization in veins: Constraints on hydration processes in oceanic peridotites, Geochemistry Geophysics Geosystems, 8, Q02012, 10.1029/2006GC001373 Asimow, 2003, The importance of water to oceanic mantle melting regimes, Nature, 421, 815, 10.1038/nature01429 Bach, 2006, Unraveling the sequence of serpentinization reactions: petrography, mineral chemistry, and petrophysics of serpentinites from MAR 15 degrees N (ODP Leg 209, Site 1274), Geophys. Res. Lett., 33, L13306, 10.1029/2006GL025681 Barclay, 2001, Microearthquake characteristics and crustal Vp/Vs structure at the Mid-Atlantic Ridge, 35°N, J. Geophys. Res., 106, 2017, 10.1029/2000JB900371 Behn, 2006, Topographic controls on dike injection in volcanic rift zones, Earth Planet. Sci. Lett., 246, 188, 10.1016/j.epsl.2006.04.005 Beslier, 1990, Kinematics of peridotite emplacement during North Atlantic continental rifting, Galicia, northwestern Spain, Tectonophysics, 184, 321, 10.1016/0040-1951(90)90446-F M.O. Beslier, G. Cornen, J. Girardeau, Tectonometamorphic evolution of peridotites from the ocean/continent of the Iberia Abyssal Plain margin. Proceedings of the Ocean Drilling Program, Scientific Results, 149 (1996) 397–412. Blackman, 1989, Axial topographic relief associated with ridge-transform intersections, Earth Planet. Sci. Lett., 95, 115, 10.1016/0012-821X(89)90171-4 Boillot, 1980, Ocean–continent boundary off the Iberian Marg in: a serpentinite diapir west of the Galicia Bank, Earth Planet. Sci. Lett., 48, 23, 10.1016/0012-821X(80)90166-1 Boillot, 1987, Tectonic denudation of the upper mantle along passive margins. A model based on drilling results (ODP LEG-103, Western Galicia Margin, Spain), Tectonophysics, 132, 335, 10.1016/0040-1951(87)90352-0 Bown, 1994, Variation with spreading rate of oceanic crustal thickness and geochemistry, Earth Planet. Sci. Lett., 121, 435, 10.1016/0012-821X(94)90082-5 Buck, 1986, Small-scale convection induced by passive rifting; the cause for uplift of rift shoulders, Earth Planet. Sci. Lett., 77, 362, 10.1016/0012-821X(86)90146-9 Cande, 1995, Revised calibration of the geomagnetic polarity timescale for the Late Cretaceous and the Cenozoic, J. Geophys. Res., 100, 6093, 10.1029/94JB03098 Cann, 1997, Corrugated slip surfaces formed at North Atlantic ridge-transform intersections, Nature, 385, 329, 10.1038/385329a0 Cannat, 1993, Emplacement of mantle rocks in the seafloor at mid-ocean ridges, J. Geophys. Res., 98, 4163, 10.1029/92JB02221 Cannat, 1996, How thick is the magmatic crust at slow spreading oceanic ridges?, J. Geophys. Res., 101, 2847, 10.1029/95JB03116 M. Cannat, J.F. Casey, 1995, An ultramafic lift at the Mid-Atlantic Ridge: Successive stages of magmatism in serpentinized peridotites from the 15°N region, in: R.L.M. Vissers, A. Nicolas (Eds.), Mantle and lower crust exposed in oceanic ridges and in ophiolites, Kluwer Academic publishers, Netherlands, pp. 5–34. Cannat, 1995, Thin crust, ultramafic exposures, and rugged faulting patterns at the Mid-Atlantic Ridge (22–24°N), Geology, 23, 49, 10.1130/0091-7613(1995)023<0049:TCUEAR>2.3.CO;2 M. Cannat, F. Chatin, H. Whitechurch, G. Ceuleneer, Gabbroic rocks trapped in the upper mantle at the Mid-Atlantic Ridge, in: J.A. Karson, M. Cannat, D.J. Miller, D. Elthon (Eds.), Proceedings of the Ocean Drilling Program, Scientific Results, vol. 153, ODP, pp. 243–264. Cannat, 1999, Formation of the axial relief at the very slow spreading Southwest Indian Ridge (49°–69°E), J. Geophys. Res., 104, 22825, 10.1029/1999JB900195 Cannat, 2002, Melt supply variations to a magma-poor ultraslow-spreading ridge (Southwest Indian Ridge 61° to 69°E), Geochemistry, Geophysics, Geosystems, 4, GC000480 M. Cannat, J.R.Cann, J. Maclennan, Some hard rock constraints on the heat supply to mid-ocean ridges, in: C. German, J. Lin, L. Parson (Eds.), Mid-Ocean Ridges: Hydrothermal Interactions Between the Lithosphere and Oceans, vol. 148: Geophysical Monograph Series, AGU, pp. 111–150. Cannat, 2006, Modes of seafloor generation at a melt-poor ultraslow-spreading ridge, Geology, 34, 605, 10.1130/G22486.1 Cannat, 2008, Spreading rate, spreading obliquity, and melt supply at the ultraslow spreading Southwest Indian Ridge, Geochemistry Geophysics Geosystems, 9, Q04002, 10.1029/2007GC001676 Chazot, 2005, Lithospheric mantle evolution during continental breakup: the West Iberia nonvolcanic passive margin, J. Petrol., 46, 2569, 10.1093/petrology/egi064 Chen, 1990, A nonlinear rheology model for mid-ocean ridge axis topography: J, Geophys. Res., 95, 17583, 10.1029/JB095iB11p17583 Chen, 1992, Oceanic crustal thickness versus spreading rate: Geophys, Res. Lett., 19, 753, 10.1029/92GL00161 Chen, 1996, The effects of spreading rate, the magma budget, and the geometry of magma emplacement on the axial heat flux at mid-ocean ridges, J Geophys. Res., 101, 11475, 10.1029/96JB00330 Chian, 1999, Deep structure of the ocean–continent transition in the southern Iberia Abyssal Plain from seismic refraction profiles: Ocean Drillng Program (Legs 149 and 173) transect, J Geophys. Res., 104, 7443, 10.1029/1999JB900004 Christensen, 1972, The abundance of serpentinites in the oceanic crust, J Geology, 80, 709, 10.1086/627796 J.R. Cochran, G. Karner. Constraints on the deformation and rupture of continental lithosphere of the Red Sea: the transition from rifting to drifting, in: G.D. Karner, G. Manatschal, L.M. Pinheiro (Eds.), Imaging, Mapping and Modelling Continental Lithosphere Extension and Breakup. Geol. Soc. London, Spec. Pub. 2007, pp. 265–290. Cochran, 2002, The Gakkel Ridge: bathymetry, gravity anomalies, and crustal accretion at extremely slow spreading rates, J Geophys. Res., 108, JB001830 Contrucci, 2004, Deep structure of the West African continental margin (Congo, Zaire, Angola), between 5 degrees S and 8 degrees S, from reflection/refraction seismics and gravity data, Geophys J. Inter., 158, 529, 10.1111/j.1365-246X.2004.02303.x Coogan, 2000, 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, 10.1016/S0012-821X(00)00006-6 G. Cornen, M.O. Beslier, J. Girardeau, Petrologic characteristics of the ultramafic rocks from the ocean–continent transition in the Iberia Abyssal Plain, in: R.B. Withmarsh, D.S. Sawyer, A. Klaus, D.G. Masson (Eds.), Proceedings of the Ocean Drilling Program, Scientific Results, vol. 149, 1996, pp. 377–395. Cornen, 1999, Basalts, underplatted gabbros and pyroxenites record the rifting process of the West Iberian margin, Min. Petrol., 67, 111, 10.1007/BF01161518 E. d’Acremont, S. Leroy, M.O. Beslier, N. Bellahsen, M. Fournier, C. Robin, M. Maia, P. Gente, Structure and evolution of the eastern Gulf of Aden conjugate margins from seismic reflection data, Geophys. J. Inter., 160 (2005) 869, doi:10.1111/j.1365-246X.2005.02524.x. Dean, 2000, Deep structure of the ocean–continent transition in the southern Iberia Abyssal Plain from seismic refraction profiles: The IAM-9 transect at 40°20’N, J. Geophys. Res., 105, 5859, 10.1029/1999JB900301 Decandia, 1972, La “zona” ofiolitifera del Bracco nel settore compreso fra Levanto e la Val Graveglia (Appennino ligure), Memorie della Società Geologica Italiana, 11, 503 Detrick, 1987, Multichannel seismic imaging of a crustal magma chamber along the East Pacific Rise between 9°N and 13°N, Nature, 326, 35, 10.1038/326035a0 H.J.B. Dick, Abyssal peridotites, very slow spreading ridges and ocean ridge magmatism, in: A.D. Saunders, M.J. Norry (Eds.), Magmatism in the Ocean Basins, vol. 24, Geol. Soc. London Spec. Pub. 1989, pp. 71–105. Dick, 2000, A long in situ section of the lower oceanic crust: results of ODP leg 176 drilling at the Southwest Indian Ridge, Earth Planet. Sci. Lett., 179, 31, 10.1016/S0012-821X(00)00102-3 Dick, 2003, An ultraslow-spreading class of ocean ridge, Nature, 426, 405, 10.1038/nature02128 H.J.B. Dick, M.A. Tivey, B.E. Tucholke, Plutonic foundation of a slow-spreading ridge segment: the oceanic core complex at Kane Megamullion, 23°30’N, 45°20’W, Geochemistry Geophysics Geosystems 9 (2008) Q05014, doi:10.1029/2007GC001645. N.G. Direen, I. Borissova, H.M.J. Stagg, J.B. Colwell, P.A. Symonds, Nature of the continent–ocean transition zone along the southern Australian continental margin: a comparison of the Naturaliste Plateau, SW Australia, and the central Great Australian Bight sectors. In: G.D. Karner, G. Manatschal and L.M. Pinheiro (Eds.), Imaging, mapping and modelling continental lithosphere extension and breakup. Geol. Soc. London, Spec. Pub., 2007, pp. 239–264. Drouin, M., Godard, M., Ildefonse, B. Origin of olivine-rich troctolites from IODP Hole U1309D in the Atlantis Massif (Mid-Atlantic Ridge): Petrostructural and Geochemical Study. Eos Trans. AGU 88 (Suppl. Fall Meet.), 2007 (Abstract T53B-1300). Emmanuel, 2006, Suppression and stimulation of seafloor hydrothermal convection by exothermic mineral hydration, Earth Planet. Sci. Lett., 243, 657, 10.1016/j.epsl.2006.01.028 Escartín, 1997, Nondilatant brittle deformation of serpentinites: Implications for Mohr–Coulomb theory and the strength of faults, J Geophys. Res., 102, 2897, 10.1029/96JB02792 Evans, 1976, Stability of chrysotile and antigorite in the serpentine multisystem: Schweiz, Miner. Petrog. Mitt., 56, 79 Florineth, 1994, Transition from continental to oceanic basement in the Tasna nappe (Engadine window, Graubünden, Switzerland): evidence for Early Cretaceous opening of the Valais ocean. Schweiz, Miner. Petrog. Mitt., 74, 437 F.J. Fontaine, W.S.D. Wilcock, Two-dimensional numerical models of open top hydrothermal convection at high Rayleigh and Nusselt numbers: Implications for mid-ocean ridge hydrothermal circulation: Geochemistry Geophysics Geosystems 8 (2007) Q07010. G. Fruh-Green, J.A.D. Connolly, A. Plas, Serpentinization of oceanic peridotites: implications for geochemical cycles and biological activity, in W.S.D. Wilcock, E.F.D., D.S. Kelley, J.A. Baross and S.C. Cary, (Eds.), The Subseafloor Biosphere at Mid-Ocean Ridges, vol. Geophysical Monograph Series 144, The American Geophysical Union, 2004, pp. 119–136. Funck, 2003, Crustal structure of the ocean–continent transition at Flemish Cap: Seismic refraction results, J. Geophys. Res. Solid Earth, 108, 2531, 10.1029/2003JB002434 T. Funck, H.R. Jackson, K.E. Louden, S.A. Dehler, Y. Wu, Crustal structure of the northern Nova Scotia rifted continental margin (eastern Canada). J. Geophys. Res. 109 (2004) B09102, doi:10.1029/2004JB003008. Gente, 1995, 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, 10.1016/0012-821X(94)00233-O Goff, 1995, Quantitative analysis of abyssal hills in the Atlantic Ocean: A correlation between axis crustal thickness and extensional faulting, J Geophys. Res., 100, 22509, 10.1029/95JB02510 T.L. Grove, R.J. Kinzler, W.B. Bryan, Fractionation of Mid-Ocean Ridge Basalt (MORB), in: J. Phipps Morgan, D.K. Blackman, J. Sinton (Eds.), Mantle flow and melt generation at mid-ocean ridges, vol. 71: Geophysical monograph, Washington, American Geophysical Union 1992, pp. 281–310. Harrison, 1987, Marine magnetic anomalies: the origin of the stripes, Ann. Rev. Earth Planet. Sci., 15, 505, 10.1146/annurev.ea.15.050187.002445 Hart, 2006, Age and geochemistry of the mafic sills. ODP site 1276, Newfoundland margin, Chem. Geol., 235, 222, 10.1016/j.chemgeo.2006.07.001 Henstock, 1993, The accretion of oceanic crust by episodic sill intrusion, J Geophys. Res., 98, 4143, 10.1029/92JB02661 Herzberg, 2004, Partial crystallization of mid-ocean ridge basalts in the crust and mantle, J Petrol., 45, 2389, 10.1093/petrology/egh040 Hirschmann, 2000, Mantle solidus: Experimental constraints and the effects of peridotite composition, Geochemistry Geophysics Geosystems, 1, 1042, 10.1029/2000GC000070 G. Hirth, J. Escartín, J. Lin, The rheology of the lower oceanic crust: implications for lithospheric deformation at Mid-Ocean ridges, in: W.R. Buck, P.T. Delaney, J.A. Karson, Y. Lagabrielle (Eds.), Faulting and magmatism at mid-ocean ridges, vol. 106: Geophysical Monograph Series, Washington D.C., AGU, pp. 291–303. A. Hosford, M.A. Tivey, T. Matsumoto, H.J.B. Dick, H. Schouten, H. Kinoshita, Crustal magnetization and accretion at the Southwest Indian Ridge near the Atlantis II fracture zone, 0–25 Ma, J. Geophys. Res. 108 (2001) JB000604 (2003). Huang, 1988, Centroid depths of Mid-Ocean ridge earthquakes: dependence on spreading rate, J. Geophys. Res., 93, 13445, 10.1029/JB093iB11p13445 Humphris, 2000, Constraints on the energy and chemical balances of the modern TAG and ancient Cyprus seafloor sulfide deposits, J. Geophys. Res., 105, 28477, 10.1029/2000JB900289 Ildefonse, 2007, Oceanic core complexes and crustal accretion at slow-spreading ridges, Geology, 35, 623, 10.1130/G23531A.1 Jagoutz, 2007, The rift-to-drift transition in the North Atlantic: A stuttering start of the MORB machine?, Geology, 35, 1087, 10.1130/G23613A.1 Jokat, 2003, Geophysical evidence for reduced melt production on the Arctic ultraslow Gakkel mid-ocean ridge, Nature, 423, 962, 10.1038/nature01706 Karner, 2000, Style, timing and distribution of tectonic deformation across the Exmouth Plateau, Northwest Australia, determined from stratal architecture and quantitative basin modelling, Geol. Soc. London, Spec. Pub., 164, 271, 10.1144/GSL.SP.1999.164.01.14 J. Karson, Seafloor spreading on the Mid-Atlantic Ridge: implications for the structure of ophiolites and oceanic lithosphere produced in slow-spreading environments, in : J. Malpas, E.M. Moores, A. Panayiotou, C. Xenophontos (Eds.), Proceedings of the Symposium “Troodos 1987”: Nycosia, Geological Survey Department, Cyprus, 1990, pp. 547–555. P.B. Kelemen, E. Kikawa, J. Miller, Shipboard Scientific Party, Igneous crystallization and localized deformation above 15km beneath the Mid-Atlantic Ridge, 14-16N (abstract): Goldschmidt Conference 2004, Copenhagen. P.B. Kelemen, E. Kikawa, D.J. Miller, et al., Proc. ODP, Init. Repts., 209: College Station, TX (Ocean Drilling Program), doi:10.2973/odp.proc.ir.209.2004. P.B. Kelemen, E. Kikawa, D.J. Miller, Shipboard Scientific Party, Leg 209 summary: processes in a 20-km-thick conductive boundary layer beneath the Mid-Atlantic Ridge, 14°–16°N, in: P.B. Kelemen, E. Kikawa, D.J. Miller (Eds.), Proc. ODP, Sci. Results, 209: College Station, TX (Ocean Drilling Program), 1–33, doi:10.2973/odp.proc.sr.209.001.2007. Klein, 1987, Global correlations of ocean ridge basalt chemistry with axial depth and crustal chemistry: J, Geophys. Res., 92, 8089, 10.1029/JB092iB08p08089 Komor, 1985, Serpentinization of cumulate ultramafic rocks from the North Arm Mountain massif of the Bay of Islands ophiolite, Geochim. Cosmochim. Acta, 49, 2331, 10.1016/0016-7037(85)90233-9 Kornprobst, 1988, Plagioclase bearing ultramafic tectonites from the Galicia margin (Leg 103 Site 637): comparison of their origin and evolution with low-pressure ultramafic bodies in Western Europe, Proc. Ocean Drill. Program Sci. Results, 103, 252 Lagabrielle, 1990, Alpine Jurassic ophiolites resemble the modern central Atlantic basement, Geology, 18, 319, 10.1130/0091-7613(1990)018<0319:AJORTM>2.3.CO;2 Lau, 2006, Crustal structure across the Grand Banks-Newfoundland Basin continental margin. II. Results from a seismic reflection profile, Geophys. J. Inter., 167, 157, 10.1111/j.1365-246X.2006.02989.x Lavier, 2006, A mechanism to thin the continental lithosphere at magma-poor margins, Nature, 440, 324, 10.1038/nature04608 Lavier, 1999, Self-consistent rolling-hinge model for the evolution of large-offset low-angle normal faults, Geology, 27, 1127, 10.1130/0091-7613(1999)027<1127:SCRHMF>2.3.CO;2 Lin, 1990, Evidence from gravity data for focused magmatic accretion along the Mid-Atlantic Ridge, Nature, 344, 627, 10.1038/344627a0 Lissenberg, 2008, Melt–rock reaction in the lower oceanic crust and its implications for the genesis of mid-ocean ridge basalts, Earth Planet. Sci. Lett., 271, 311, 10.1016/j.epsl.2008.04.023 Lizarralde, 2004, Spreading rate dependence of melt extraction at mid-ocean ridges from mantle seismic refraction data, Nature, 432, 744, 10.1038/nature03140 Lowell, 2007, Numerical simulations of single-pass hydrothermal convection at mid-ocean ridges: Effects of the extrusive layer and temperature-dependent permeability, Geochemistry, Geophysics, Geosystems, 8, Q10011, 10.1029/2007GC001653 Magde, 1997, The relationship beween buoyant mantle flow, melt migration and bull's eyes at the Mid-Atlantic Ridge between 33°N and 35°N, Earth Planet. Sci. Lett., 148, 59, 10.1016/S0012-821X(97)00039-3 Manatschal, 1997, A continent–ocean transition recorded in the Err and Platta nappes (eastern Switzerland), Eclogae Geol. Helv., 90, 3 G. Manatschal, N. Froitzheim, M. Rubenach, B.D. Turrin, The role of detachment faulting in the formation of an ocean–continent transition: Insights from the Iberia Abyssal Plain, in: Nonvolcanic Rifting of Continental Margins: A Comparison of Evidence From Land and Sea. R.C.L. Wilson et al. (Eds.), Geolog. Soc. London, Spec. Pub., 187, 2001, pp. 405–428. G. Manatschal, O. Müntener, L.L. Lavier, T.A. Minshull, G. Péron-Pinvidic, Observations from the Alpine Tethys and Iberia–Newfoundland margins pertinent to the interpretation of continental breakup. in: G.D. Karner, G. Manatschal, L.M. Pinheiro (Eds), Imaging, Mapping and Modelling Continental Lithosphere Extension and Breakup. Geol. Soc. London, Spec. Pub., 2007, pp. 291–324. Martin, 1970, Some experimental and theoritical observations on the kinetics of hydration reactions with particular reference to serpentinization, Chem. Geol., 6, 185, 10.1016/0009-2541(70)90018-5 McCaig, 2007, Oceanic detachment faults focus very large volumes of black smoker fluids, Geology, 35, 935, 10.1130/G23657A.1 McKenzie, 1978, Some remarks on the development of sedimentary basins, Earth Planet. Sci. Lett., 40, 25, 10.1016/0012-821X(78)90071-7 McKenzie, 1984, The generation and compaction of partially molten rock, J. Petrol., 25, 713, 10.1093/petrology/25.3.713 McKenzie, 1988, The volume and composition of melt generated by extension of the lithosphere, J. Petrol., 29, 625, 10.1093/petrology/29.3.625 Mendel, 1997, Segmentation and morphotectonic variations along a superslow spreading center: the Southwest Indian Ridge (57°E–70°E), Mar. Geophys. Res., 19, 505, 10.1023/A:1004232506333 Meyzen, 2003, A discontinuity in mantle composition beneath the Southwest Indian Ridge, Nature, 421, 731, 10.1038/nature01424 Michael, 1998, Influence of spreading rate and magma supply on crystallization and assimilation beneath mid-ocean ridges: Evidence from chlorine and major chemistry of mid-ocean ridge basalts, J. Geophys. Res., 103, 18325, 10.1029/98JB00791 Michael, 2003, Magmatic and amagmatic seafloor generation at the ultraslow-spreading Gakkel ridge, Arctic Ocean, Nature, 423, 956 D.J. Miller, 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): Proceedings of the Ocean Drilling Program, Scientific Results, 153, 1997, pp. 437–454. T.A. Minshull, M.R. Muller, C.J. Robinson, R.S. White, M.J. Bickle, Is the oceanic Moho a serpentinization front?, in: R.A. Mills, K. Harrison (Eds.), Modern Ocean Floor Processes and the Geological Record, vol. 148: Geol. Soc., London, Spec. Pub., 1998, pp. 71–80. T.A. Minshull, S.M. Dean, R.S. White, R.B. Whitmarsh, Anomalous melt production after continental breakup in the southern Iberian Abyssal Plain, in: R.C.L. Wilson, R.B. Whitmarsh, B. Taylor, N. Froitzheim (Eds.), Nonvolcanic rifting of continental margins: A comparison of evidence from land and sea, The Geological Society of London, vol.181, 2001, pp. 537–550. Mittelstaedt, 2008, Mid-ocean ridge jumps associated with hotspot magmatism, Earth Planet Sci. Lett., 266, 256, 10.1016/j.epsl.2007.10.055 Moretti, 1987, The evolution of the Suez rift: a combination of stretching and secondary convection, Tectonophysics, 133, 229, 10.1016/0040-1951(87)90266-6 Morton, 1985, A mid-ocean ridge thermal model: Constraints on the volume of axial hydrothermal heat flux, J. Geophys. Res., 90, 11345, 10.1029/JB090iB13p11345 Moulin, 2005, Geological constraints on the evolution of the Angolan margin based on reflection and refraction seismic data (ZaïAngo project), Geophys. J. Inter., 162, 793, 10.1111/j.1365-246X.2005.02668.x Muller, 1999, Segmentation and melt supply at the Southwest Indian Ridge, Geology, 27, 867, 10.1130/0091-7613(1999)027<0867:SAMSAT>2.3.CO;2 Müntener, 2006, High degrees of melt extraction recorded by spinel harzburgite of the Newfoundland margin: The role of inheritance and consequences for the evolution of the southern North Atlantic, Earth Planet. Sci. Lett., 252, 437, 10.1016/j.epsl.2006.10.009 Müntener, 2004, Refertilization of mantle peridotite in embryonic ocean basins: Trace element and Nd-isotopic evidence and implications for crust–mantle relationships, Earth Planet. Sci Lett., 221, 293, 10.1016/S0012-821X(04)00073-1 Nazarova, 1994, Serpentinized peridotites as a possible source for oceanic magnetic anomalies, Mar. Geophys. Res., 16, 455, 10.1007/BF01270519 Neumann, 1993, The paradox of the axial profile: Isostatic compensation along the axis of the Mid-Atlantic Ridge?, J. Geophys. Res., 98, 17891, 10.1029/93JB01550 Nicolas, 1988, A new magma chamber model based on structural studies in the Oman Ophiolite, Tectonophysics, 151, 87, 10.1016/0040-1951(88)90242-9 O’Hanley, 1992, Solution to the volume problem in serpentinization, Geology, 20, 705, 10.1130/0091-7613(1992)020<0705:STTVPI>2.3.CO;2 Okino, 2002, Preliminary analysis of the Knipovich Ridge segmentation: influence of focused magmatism and ridge obliquity on an ultraslow spreading system, Earth Planet. Sci. Lett., 202, 275, 10.1016/S0012-821X(02)00790-2 O. Oufi, M. Cannat, H. Horen, Magnetic properties of variably serpentinized abyssal peridotites, J. Geophys. Res., 107 (2002) 10.1029/2001JB000549. Pariso, 1996, Three-dimensional inversion of marine magnetic anomalies: implications for crustal accretion along the Mid-Atlantic Ridge (28°–31°30’N), Mar. Geophys. Res., 18, p85, 10.1007/BF00286204 Perez-Gussinye, 2006, The rift to drift transition at nonvolcanic margins: Insights from numerical modelling, Earth Planet. Sci. Lett., 244, 458, 10.1016/j.epsl.2006.01.059 G. Péron-Pinvidic, G. Manatschal, The final rifting evolution at deep magma-poor passive margins from Iberia–Newfoundland: a new point of view. Inter. J. Earth Sci., 17 (2008) doi : 10.1007/s00531-008-0337-9. G. Péron-Pinvidic, G. Manatschal, T.A. Minshull, D.S. Sawyer, Tectonosedimentary evolution of the deep Iberia–Newfoundland margins: Evidence for a complex breakup history: Tectonics, 26 (2007) TC2011, doi:10.1029/2006TC001970. G. Péron-Pinvidic, D. Shillington, B. Tucholke, Characterization of the U reflection on the Newfoundland margin: Evidence for widespread early postrift magmatism on “magma-poor” rifted margin. AGU —American Geosciences Union, Fall Meeting 2007, San Francisco (United States), December 10–14, 2007 (Session T14). Phipps Morgan, 1988, Three-dimensional flow and temperature perturbations due to a transform offset: Effects on oceanic crustal and upper mantle structure, J. Geophys. Res., 93, 2955, 10.1029/JB093iB04p02955 Phipps Morgan, 1987, Mechanisms for the origin of Mid-Ocean Ridge axial topography: implications for the thermal and mechanical structure of accreting plate boundaries, J. Geophys. Res., 92, 12823, 10.1029/JB092iB12p12823 Piccardo, 2004, Ophiolitic peridotites of the Alpine–Apennine system: Mantle processes and geodynamic relevance, Inter. Geol. Rev., 46, 1119, 10.2747/0020-6814.46.12.1119 Pockalny, 1995, Spatial and temporal variability of crustal magnetization of a slowly spreading ridge: Mid-Atlantic ridge (20°–24°N), Mar. Geophys. Res., 17, 301, 10.1007/BF01203467 M. Rabinowicz,A. Briais, Temporal variations of the segmentation of slow- to intermediate-spreading mid-ocean ridges. 2. A three-dimensional model in terms of lithospheric accretion and convection within the partially molten mantle: J. Geophys. Res. 107 (2002) 10.1029/2001JB000343. Rabinowicz, 1987, Melt segregation and flow in mantle diapirs below spreading centers. Evidence from the Oman Ophiolite, J. Geophys. Res. Solid Earth and Planets, 92, 3475, 10.1029/JB092iB05p03475 Rabinowicz, 1993, 3-dimensional mantle flow beneath midocean ridges, J Geophys. Res. Solid Earth, 98, 7851, 10.1029/92JB02740 Raleigh, 1965, Experimental deformation of serpentinite and its tectonic implications, J. Geophys. Res., 70, 3965, 10.1029/JZ070i016p03965 Reid, 1981, Oceanic spreading rate and crustal thickness, Mar. Geophys. Res., 5, 165 Reinen, 1991, The frictional behavior of serpentinite: implications for aseismic creep on shallow crustal fault, Geophys Res. Lett., 18, 1921, 10.1029/91GL02367 Reston, 1996, The S reflector west of Galicia (Spain): Evidence from prestack depth migration for detachment faulting during continental breakup, J. Geophys. Res., 101, 8075, 10.1029/95JB03466 Russell, 2003, Magmatism at the west Iberia nonvolcanic rifted continental margin: evidence from analyses of magnetic anomalies, Geophys. J. Inter., 154, 706, 10.1046/j.1365-246X.2003.01999.x Sauter, 2002, TOBI sidescan sonar imagery of the very slow spreading Southwest Indian Ridge: evidence for along-axis magma distribution, Earth Planet. Sci. Lett., 1999, 81, 10.1016/S0012-821X(02)00543-5 D. Sauter, M. Cannat, V. Mendel, Magnetization of 0–26.5 Ma seafloor at the ultraslow-spreading Southwest Indian Ridge 61–67°E: Geochemistry, Geophysics, Geosystems 9 (2008) Q04023, doi:10.1029/2007GC001764. D.S. Sawyer, R.B. Whitmarsh, A. Klaus, et al., Proc. ODP, Init. Repts, 149: College Station, TX (Ocean Drilling Program), 1994, doi:10.2973/odp.proc.ir.149. Schärer, 2000, 138–121 Ma asthenospheric magmatism prior to continental breakup in the North Atlantic and geodynamic implications, Earth Planet. Sci. Lett., 181, 555, 10.1016/S0012-821X(00)00220-X Sempéré, 1990, Segmentation of the Mid-Atlantic Ridge between 24°N and 30°40’N, Nature, 344, 427, 10.1038/344427a0 Severinghaus, 1988, High inside corners at ridge-transform intersections, Mar. Geophys. Res., 9, 353, 10.1007/BF00315005 Seyler, 2001, Clinopyroxene microtextures reveal incompletely extracted melts in abyssal peridotites, Geology, 29, 155, 10.1130/0091-7613(2001)029<0155:CMRIEM>2.0.CO;2 M. Seyler, M. Cannat, C. Mével, Evidence for major element heterogeneity in the mantle source of abyssal peridotites from the southwest Indian Ridge (52 to 68° East), Geochemistry, Geophysics, Geosystems 4 (2003) 2002GC000305. Seyler, 2007, Pervasive melt percolation reactions in ultradepleted refractory harzburgites at the Mid-Atlantic Ridge, 15°20’N: ODP Hole 1274A, Contrib. Mineral. Petrol., 153, 303, 10.1007/s00410-006-0148-6 Shaw, 1996, Models of ocean ridge lithospheric deformation: Dependence on crustal thickness, spreading rate, and segmentation, J. Geophys. Res., 101, 17977, 10.1029/96JB00949 Shipboard Scientific Party, Introduction, objectives, and principal results: Ocean Drilling Program Leg103, West Galicia margin. G. Boillot, E.L. Winterer, A.W. Meyer et al., Proceedings of the Ocean Drilling Program, Initial Reports, 103, 1987, pp. 3–17. J.C. Sibuet, S. Srivastava, G. Manatschal, Exhumed mantle forming transitional crust in the Newfoundland–Iberia rift and associated magnetic anomalies, J. Geophys. Res. 112 (2007) B06105, doi:10.1029/2005JB003856. Skelton, 2000, The relative timing of serpentinisation and mantle exhumation at the ocean–continent transition, Iberia: constraints from oxygen isotopes, Earth Planet. Sci. Lett., 178, 327, 10.1016/S0012-821X(00)00087-X Sleep, 1975, Formation of oceanic crust: Some thermal constraints, J. Geophys. Res., 80, 4037, 10.1029/JB080i029p04037 Sleep, 1997, The nature of the lower crust and shallow mantle emplacement at low spreading rates, Tectonophysics, 279, 181, 10.1016/S0040-1951(97)00121-2 C. Small, Global systematics of mid-ocean ridge morphology, in: W.R. Buck, P.T. Delaney, J.A. Karson, Y. Lagabrielle (Eds.), Faulting and magmatism at mid-ocean ridges, vol. 106: Geophysical Monograph Series: Washington D.C., AGU, 1998, pp. 1–25. Smith, 1999, Constructing the upper crust of the Mid-Atlantic Ridge; a reinterpretation based on the Puna Ridge, Kilauea volcano, J. Geophys. Res., 104, 25379, 10.1029/1999JB900177 D.K. Smith, J. Escartin, H. Schouten, J.R. Cann, Fault rotation and core complex formation: Significant processes in seafloor formation at slow-spreading mid-ocean ridges (Mid-Atlantic Ridge, 13 degrees–15 degrees N): Geochemistry, Geophysics Geosystems 9 (2008) Q03003, doi:10.1029/2007GC001699. Sotin, 1989, Dynamical consequences of compositional and thermal density stratification beneath spreading centers, Geophys Res. Lett., 16, 835, 10.1029/GL016i008p00835 Sparks, 1991, Melt extraction from the mantle beneath spreading centers, Earth Planet. Sci. Lett., 105, 368, 10.1016/0012-821X(91)90178-K Srivastava, 2000, Magnetic evidence for slow seafloor spreading during the formation of the Newfoundland and Iberian margins, Earth Planet. Sci. Lett., 182, 61, 10.1016/S0012-821X(00)00231-4 Stein, 1994, Constraints on hydrothermal heat flux through the oceanic lithosphere from global heat flow, J. Geophys. Res., 99, 3081, 10.1029/93JB02222 G. Suhr, P. Kelemen, H. Paulick, Microstructures in Hole 1274A peridotites, ODP Leg 209, Mid-Atlantic Ridge: Tracking the fate of melts percolating in peridotite as the lithosphere is intercepted: Geochemistry, Geophysics, Geosystems 9 (2008) Q03012, doi:10.1029/2007GC001726. A.J. Tankard, H.J. Welsink, W.A.M. Jenkins, Structural styles and stratigraphy of the Jeanne d’Arc Basin, Grand Banks of Newfoundland, in: A.J. Tankard, H.R. Balkwill (Eds.), Extensional Tectonics and Stratigraphy of the North Atlantic Margins, Amer. Assoc. Petroleum Geol. Mem. 46, 1989, pp. 265–282. Tivey, 1998, Magnetization of 0–29 Ma ocean crust on the Mid-Atlantic Ridge, 25°30’ to 27°10’N, J. Geophys. Res., 103, 17807, 10.1029/98JB01394 Toft, 1990, The effect of serpentinization on density and magnetic susceptibility: a petrophysical model, Phys Earth Planet. Inter., 65, 137, 10.1016/0031-9201(90)90082-9 Tolstoy, 1993, Crustal thickness on the Mid-Atlantic Ridge: Bull's eye gravity anomalies and focused accretion, Science, 262, 726, 10.1126/science.262.5134.726 Toomey, 1985, Microearthquakes beneath the median valley of the Mid-Atlantic ridge near 23°N: hypocenters and focal mechanisms, J. Geophys. Res., 90, 5443, 10.1029/JB090iB07p05443 Toomey, 1988, Microearthquakes beneath the median valley of the Mid-Atlantic ridge near 23°N: tomography and tectonics, J. Geophys. Res., 93, 9093, 10.1029/JB093iB08p09093 B.E. Tucholke, J.C. Sibuet, Leg 210 Synthesis: Tectonic, Magmatic, and Sedimentary Evolution of the Newfoundland–Iberia Rift, in: B.E. Tucholke, J.C. Sibuet (Eds), Scientific Results. Ocean Drilling Program, Texas A&M University, College Station, TX, 2007, pp. 1–56. Tucholke, 1998, Megamullions and mullion structure defining oceanic metamorphic core complexes on the Mid-Atlantic Ridge, J. Geophys. Res., 103, 9857, 10.1029/98JB00167 B.E. Tucholke, J.C. Sibuet, A. Klaus, et al., Proc. ODP, Init. Repts., 210: College Station, TX (Ocean Drilling Program), 2004, doi:10.2973/odp.proc.ir.210.2004. Tucholke, 2008, Role of melt supply in oceanic detachment faulting and formation of megamullions, Geology, 36, 455, 10.1130/G24639A.1 Van Avendonk, 2006, Seismic velocity structure of the rifted margin of the eastern Grand Banks of Newfoundland, Canada, J. Geophys. Res. Solid Earth, 111, 404, 10.1029/2005JB004156 Van Avendonk, 2009, Extension of continental crust at the margin of the eastern Grand Banks, Newfoundland, Tectonophysics, 468, 131, 10.1016/j.tecto.2008.05.030 White, 2001, Melt generation at very slow-spreading oceanic ridges: Constraints from geochemical and geophysical data, J. Petrol., 42, 1171, 10.1093/petrology/42.6.1171 Whitmarsh, 1995, Models of the development of the West Iberia rifted continental margin at 40°30’N deduced from surface and deep-tow magnetic anomalies, J. Geophys. Res., 100, 3789, 10.1029/94JB02877 R.B. Whitmarsh, M.O. Beslier, P.J. Wallace, et al., Proc. ODP, Init. Repts., 173: College Station, TX (Ocean Drilling Program), 1998, doi:10.2973/odp.proc.ir.173.1998. Whitmarsh, 2001, Evolution of magma-poor continental margins from rifting to seafloor spreading, Nature, 413, 150, 10.1038/35093085 Wilcock, 1996, Mid-ocean ridge sulfide deposits: Evidence for heat extraction from magma chambers or cracking fronts?, Earth Planet. Sci. Lett., 145, 49, 10.1016/S0012-821X(96)00195-1 Wolfe, 1995, Microearthquake characteristics and crustal velocity structure at 29°N of the Mid-Atlantic Ridge: The architecture of a slow-spreading segment, J. Geophys. Res., 100, 24449, 10.1029/95JB02399