P. Agrinier and M. Cannat, Oxygen isotopic constraints on serpentinization processes in ultramafic rocks from the Mid-Atlantic Ridge (lat. 23°N), in the MARK area, Proc. Ocean Drill. Program Sci. Results, vol.153, pp.381-388, 1997.

P. Agrinier, R. Hekinian, D. Bideau, and M. Javoy,

, C) of oceanic crust and upper mantle rocks in the Hess Deep near the Galapagos Triple Juction, vol.136, pp.183-196, 1996.

S. Arai and T. Fujii, Petrology of ultramafic rocks from site 395, Initial Rep. Deep Sea Drill. Proj, vol.45, pp.587-594, 1978.

K. S. Argyle and D. J. Dunlop, Low-temperature and high-temperature hysteresis of small multidomain magnetites (215 -540 nm), J. Geophys. Res, vol.95, pp.7069-7083, 1990.

K. S. Argyle, D. J. Dunlop, and S. Xu, Single-domain behaviour of multidomain magnetite grains (abstract), Fall Meet, vol.75, 1994.

M. M. Bina, B. Henry, M. M. Bina, Y. Hamano, K. Krammer et al., Magnetic properties, opaque mineralogy and magnetic anisotropies of serpentinized peridotites from ODP Hole 670A near the Mid-Atlantic Ridge, Paleomagnetisme of basalts from ODP hole 648B on the Mid-Atlantic Ridge, Proc. Ocean Drill. Program Sci. Results, 106/109, vol.65, pp.291-295, 1990.

H. Bougault, Initial Reports of the Deep Sea Drilling Project, vol.82, 1985.

R. F. Butler and S. K. Banerjee, Theoretical single-domain grain-size range in magnetite and titanomagnetite, J. Geophys. Res, vol.80, pp.4049-4058, 1975.

J. P. Canales, 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, vol.105, pp.2699-2719, 2000.

M. Cannat, Emplacement of mantle rocks in the seafloor at mid-ocean ridges, J. Geophys. Res, vol.98, pp.4163-4172, 1993.

M. Cannat, Ultramafic and gabbroic exposures at the Mid-Atlantic Ridge: Geological mapping in the 15°N region, Proceedings of the Ocean Drilling Program, vol.153, pp.193-213, 1995.

L. Caruso and J. V. Chernosky, The stability of lizardite, Can. Mineral, vol.17, pp.757-769, 1979.

N. I. Christensen, The abundance of serpentinites in the oceanic crust, J. Geol, vol.80, pp.709-719, 1972.

N. I. Christensen, Ophiolites, seismic velocities and oceanic crustal structure, Tectonophysics, vol.47, pp.131-157, 1978.

P. Dankers, Relationship between median destructive field and remanent coercive forces for dispersed natural magnetite, titanomagnetite and hematite, Geophys. J. R. Astron. Soc, vol.64, pp.447-461, 1981.

R. Day, M. D. Fuller, and V. A. Schmidt, Hysteresis properties of titanomagnetites: Grain size and composition dependance, Phys. Earth Planet. Inter, vol.13, pp.260-267, 1977.

R. Day, S. Halgedahl, M. Steiner, K. Kobayashi, T. Furuta et al., Magnetic properties of basalts from DSDP Leg 49, Initial Rep. Deep Sea Drill. Proj, vol.49, pp.781-791, 1979.

R. Detrick, Proceedings of the Ocean Drilling Program, vol.106, pp.291-295, 1988.

H. J. Dick and J. H. Natland, Late-stage evolution and transport in the shallow mantle beneath the East Pacific Rise, Proc. Ocean Drill. Program Sci. Results, vol.147, pp.103-134, 1996.

Y. Dilek, A. Coulton, and S. D. Hurst, Serpentinization and hydrothermal veining in peridotites at site 920 in the MARK area, Proc. Ocean Drill. Program Sci. Results, vol.153, pp.35-59, 1997.

D. J. Dunlop, Hysteretic properties of synthetic and natural monodomain grains, Philos. Mag, vol.19, pp.329-338, 1969.

D. J. Dunlop, Superparamagnetic and single-domain threshold sizes in magnetite, J. Geophys. Res, vol.78, pp.1780-1793, 1973.

D. J. Dunlop, The rock magnetism of fine particles, Phys. Earth Planet. Inter, vol.26, pp.1-26, 1981.

D. J. Dunlop, Hysteresis properties of magnetite and their dependence on particle size: A test of pseudo-single-domain remanence models, J. Geophys. Res, vol.91, pp.9569-9584, 1986.

D. J. Dunlop, Ö. Zdemir, and R. Magnetism, Fundamentals and Frontiers, 565 pp, 1997.

D. J. Dunlop and M. Prévot, Magnetic properties and opaque mineralogy of drilled submarine intrusive rocks, Geophys. J. R. Astron. Soc, vol.69, pp.763-802, 1982.

D. J. Dunlop and G. F. West, An experimental evaluation of single domain theories, Rev. Geophys, vol.7, pp.709-757, 1969.

J. Dyment and J. Arkani-hamed, Spreading-rate-dependent magnetization of the oceanic lithosphere inferred from the anomalous skewness of marine magnetic anomalies, Geophys. J. Int, vol.121, pp.789-804, 1995.

J. Dyment, J. Arkani-hamed, and A. Ghods, Contribution of serpentinized ultramafics to marine magnetic anomalies at slow and intermediate spreading centres: Insights from the shape of the anomalies, Geophys. J. Int, vol.129, pp.691-701, 1997.

J. Francheteau, R. Armijo, J. L. Cheminée, R. Hékinian, P. Lonsdale et al., 1 Ma East Pacific Rise oceanic crust and uppermost mantle exposed by rifting in Hess Deep (equatorial Pacific Ocean), Earth Planet. Sci. Lett, vol.101, pp.281-295, 1990.

G. L. Früh-green, A. Plas, B. Grobéty, and C. Lécuyer, Multi-stage hydrothermal alteration and antigorite serpentinization of EPR shallow mantle at Hess Deep, Terra Abstr, vol.7, p.208, 1995.

G. L. Früh-green, A. Plas, and C. Lécuyer, Petrological and stable isotope constraints on hydrothermal alteration and serpentinization of the EPR shallow mantle at Hess Deep (site 895), Proc. Ocean Drill. Program Sci. Results, vol.147, pp.255-291, 1996.

I. Ghose, M. Cannat, and M. Seyler, Transform fault effect on mantle melting in the MARK area (Mid-Atlantic Ridge south of the Kane transform), Geology, vol.24, pp.1139-1142, 1996.

E. Gracia, D. Bideau, R. Hekinian, and Y. Lagabrielle, Detailed geological mapping of two contrasting second-order segments of the Mid-Atlantic Ridge between Oceanographer and Hayes fracture zones (33°30 0 NÀ35°N), J. Geophys. Res, vol.104, pp.903-925, 1999.

Y. Hamano, M. M. Bina, and K. Krammer, Paleomagnetism of the serpentinized peridotite from ODP Hole 670A, Proc. Ocean Drill. Program Sci. Results, 106/109, pp.257-262, 1990.

R. Hébert, A. C. Adamson, and S. C. Komor, Metamorphic petrology of ODP leg 109, hole 670A, serpentinized peridotites: Serpentinization processes at a slow spreading ridge environment, Proc. Ocean Drill. Program Sci. Results, vol.106, pp.103-106, 1990.

F. Heider, D. J. Dunlop, and N. Sugiura, Magnetic properties of hydrothermally recrystallized magnetite crystals, Science, vol.236, pp.1287-1290, 1987.

F. Heider, A. Zitzelsberger, and K. Fabian, magnetic susceptibility and remanent coercivity force in grown magnetite crystals from 0.1 mm to 6 mm, Phys. Earth Planet. Inter, vol.93, pp.239-256, 1996.

H. Horen and G. Dubuisson, Rôle de l'hydrothermalisme sur les propriétés magnétiques d'une lithosphère océanique formée à une ride lente: L'ophiolite de Xigaze (Tibet), C. R. Acad. Sci., Ser. IIa, vol.312, pp.1095-1102, 1995.

H. Horen, M. Zamora, and G. Dubuisson, Seismic waves velocities and anisotropy in serpentinized peridotites from Xigaze ophiolite: Abundance of serpentine at slow spreading ridges, Geophys. Res. Lett, vol.23, pp.9-12, 1996.

S. Hornes, H. Friedrichsen, and H. H. Schock, Oxygen-and hydrogenisotope and trace-element investigation on rocks of DSDP Hole 395A, Initial Rep. Deep Sea Drill. Proj, vol.45, pp.541-550, 1978.

P. H. Johnson, Rock magnetic properties of samples-DSDP Leg 45, Initial Rep. Deep Sea Drill. Proj, vol.45, pp.397-406, 1978.

J. A. Karson, S. D. Hurst, and P. Lonsdale, Tectonic rotation of dikes in fast-spread oceanic crust exposed near Hess Deep, Geology, vol.20, pp.685-688, 1992.

P. R. Kelso, C. Richter, and J. E. Pariso, Rock magnetic properties, magnetic mineralogy and paleomagnetism of peridotite from site 895, Hess Deep, Proc. Ocean Drill. Program Sci. Results, vol.147, pp.405-413, 1996.

S. C. Komor, D. Elthon, and F. J. Casey, serpentinization of cumulate ultramafic rocks the North Arm Moutain massif of the Bay of Islands ophiolite, Geochim. Cosmochim. Acta, vol.49, pp.2331-2338, 1985.

S. C. Komor, T. L. Grove, and R. Hébert, Abyssal peridotites from ODP Hole, vol.670, pp.21-31

N. ,

, Residues of mantle melting exposed by non-constructive axial divergence, Proc. Ocean Drill. Program Sci. Results, vol.106, pp.85-1001, 1990.

K. Krammer, Rock magnetic properties and opaque mineralogy of selected samples from Hole 670A, Proc. Ocean Drill. Program Sci. Results, 106/109, pp.269-273, 1990.

Y. Lagabrielle and M. Cannat, Alpine jurassic ophiolites resemble the modern central Atlantic basement, Geology, vol.18, pp.319-322, 1990.

B. R. Lienert and P. G. Wasilewski, A magnetic study of the serpentinization process at Burro Mountain, California, Earth Planet. Sci. Lett, vol.43, pp.406-416, 1979.

W. G. Melson, Initial Reports of the Deep Sea Drilling Project, vol.45, 1976.

W. G. Melson, P. D. Rabinowitz, J. H. Natland, H. Bougault, and H. P. Johnson, Initial Reports of the Deep Sea Drilling Project, vol.45, pp.587-594, 1978.

C. Mével and C. Stamoudi, Hydrothermal alteration of the upper-mantle section at Hess Deep, Proc. Ocean Drill. Program Sci. Results, vol.147, pp.293-309, 1996.

C. Mével, Proceedings of the Ocean Drilling Program, vol.147, 1993.

P. J. Michael and E. Bonatti, Petrology of ultramafic rocks from sites 556, 558 and 560 in the North Atlantic, Initial Rep. Deep Sea Drill. Proj, vol.82, pp.523-528, 1985.

D. J. Miller 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, vol.153, pp.437-454, 1997.

J. Moody, An experimental study on the serpentinization of iron-bearing olivines, Can. Mineral, vol.14, pp.462-478, 1976.

K. A. Nazarova, Serpentinized peridotites as a possible source for oceanic magnetic anomalies, Mar. Geophys. Res, vol.16, pp.455-462, 1994.

K. Niida, Mineralogy of MARK peridotites: Replacement through magma channeling examined from Hole 920D, MARK area, Proc. Ocean Drill. Program Sci. Results, vol.153, pp.265-275, 1997.

D. S. O'hanley, M. D. Dyar, ;. O'hanley, D. S. , and M. D. Dyar, The composition of lizardite 1T and the formation of magnetite in serpentines, Can. Mineral, vol.78, pp.727-739, 1993.

O. Oufi, Les propriétés magnétiques des péridotite serpentinisées abyssales: Relation entre la composition chimique, la nature minéralogique des minéraux serpentineux et le comportement magnétique des pérido-tites serpentinisées, 2000.

Ö. Ö-zdemir and D. J. Dunlop, Domain structure observations in biotite and hornblendes, vol.73, 1992.

N. G. Page, Chemical differences among the serpentine ''polymorphs, Am. Mineral, vol.53, pp.201-215, 1968.

J. E. Pariso, C. Rommevaux, and J. C. Sempéré, Three-dimensional inversion of marine magnetic anomalies: Implications for crustal accretion along the Mid-Atlantic Ridge, pp.28-31

L. G. Parry, Magnetic properties of dispersed magnetite powders, Mar. Geophys. Res, vol.18, pp.303-312, 1965.

R. A. Pockalny, A. Smith, and P. Gente, Spatial and temporal variability of crustal magnetization of a slowly spreading ridge: Mid-Atlantic Ridge (20°-24°N), Mar. Geophys. Res, vol.17, pp.301-320, 1995.

A. A. Rahman, A. D. Duncan, and L. G. Parry, Magnetization of multidomain magnetite particles, Riv. Ital. Geofis, vol.22, pp.259-266, 1973.

M. Ravilly, J. Dyment, P. Gente, and R. Thibaud, Axial magnetic anomaly amplitude along the Mid-Atlantic Ridge between 20°N and 40°N, J. Geophys. Res, vol.103, pp.201-225, 1998.

C. Richter, P. R. Kelso, and J. M. Christopher, Magnetic fabrics and sources of magnetic susceptibility in lower crustal and upper mantle rocks from Hess Deep, Proc. Ocean Drill. Program Sci. Results, vol.147, pp.393-403, 1996.

W. R. Roest, J. Arkani-hamed, and J. Verhoef, The seafloor spreading rate dependence of the anomalous skewness of marine magnetic anomalies, Geophys. J. Int, vol.109, pp.653-669, 1992.

V. P. Shcherbakov and V. V. Shcherbakova, Calculation of thermoremanence and ideal magnetization of an ensemble of interacting single-domain grains, Izv. Phys. Solid Earth, Engl. Transl, vol.18, pp.413-421, 1977.

V. P. Shcherbakov, B. E. Lamash, and N. K. Sycheva, Monte Carlo modelling of thermoremanence acquisition in interacting single-domain grains, Phys. Earth. Planet. Inter, vol.87, pp.197-211, 1995.

J. M. Sinton, Consequences of the maghemitization on the magnetic properties of submarine basalts: Synthesis of previous works and results concerning basement rocks from mainly DSDP Legs 51 and 52, Initial Rep. Deep Sea Drill. Proj, vol.45, pp.206-226, 1978.

G. M. Smith and S. K. Banerjee, Magnetic properties of plutonic rocks from the central North Atlantic Ocean, Initial Rep. Deep Sea Drill. Proj, vol.82, pp.377-383, 1985.

F. D. Stacey, A generalized theory of thermoremanence, covering the transition from single domain to multi-domain magnetic grains, Philos. Mag, vol.7, pp.1887-1900, 1962.

F. D. Stacey and S. K. Banerjee, The Physical Principles of Rock Magnetism, 1974.

E. C. Stoner and E. P. Wohlfarth, A mechanism of magnetic hysteresis in heterogeneous alloys, Philos. Trans. R. Soc. London, Ser. A, vol.240, pp.599-642, 1948.

M. Talwani, C. C. Windisch, and M. G. Langseth, Reykjanes crest: A detailed geophysical study, J. Geophys. Res, vol.76, pp.473-517, 1971.

M. A. Tivey and B. E. Tucholke, Magnetization of 0-29 Ma ocean crust on the Mid-Atlantic Ridge

N. and J. , Geophys. Res, vol.103, pp.807-824, 1998.

P. B. Toft, J. Arkani-hamed, and S. E. Haggerty, The effects of serpentinization on density and magnetic susceptibility: A petrophysical model, Phys. Earth Planet. Inter, vol.65, pp.137-157, 1990.

B. E. Tucholke and J. Lin, A geological model for the structure of ridge segments in slow spreading ocean crust, J. Geophys. Res, vol.99, pp.937-948, 1994.

E. J. Whittaker and F. J. Wicks, Chemical differences among the serpentine ''polymorphs'': A discussion, Am. Mineral, vol.55, pp.1025-1047, 1970.

E. J. Whittaker and J. Zussman, The characterization of serpentine minerals by X-ray diffraction, Mineral. Mag, vol.31, pp.107-126, 1956.

F. J. Wicks and D. S. O'hanley, Serpentines: Structure and petrology, Hydrous Phyllosilicates Exclusive of Micas, vol.19, pp.91-168, 1988.

F. J. Wicks and G. Plant, Electron microphobe and X-ray microbeam studies of serpentine textures, Can. Mineral, vol.17, pp.785-830, 1979.

F. J. Wicks and E. J. Whittaker, Serpentine textures and serpentinization, Can. Mineral, vol.15, pp.459-488, 1977.

E. P. Wohlfarth, Relations between different modes of acquisition of the remanent magnetization of titanomagnetic particles, J. Appl. Phys, vol.29, pp.595-596, 1958.

H. U. Worm and H. Markert, Magnetic hysteresis properties of fine particle titanomagnetites precipitated in a silicate matrix, Phys. Earth. Planet. Inter, vol.46, pp.84-92, 1987.

M. Cannat and O. Oufi, Laboratoire de Géosciences Marine, CNRS/IPGP

H. Horen, Laboratoire de Géologie, ENS, 24 rue Lhomond, F-75231