Abstract
In 1994, a joint Japanese-American dive program utilizing the worlds deepest diving active research submersible (SHINKAI 6500) was carried out at the western ridge-transform intersection (RTI) of the Mid-Atlantic Ridge and Kane transform in the central North Atlantic Ocean. A total of 15 dives were completed along with surface-ship geophysical mapping of bathymetry, magnetic and gravity fields. Dives at the RTI traced the neovolcanic zone up to, and for a short distance (2.5 km) along, the Kane transform. At the RTI, the active trace of the transform is marked by a narrow valley (<50 m wide) that separates the recent lavas of the neovolcanic zone from the south wall of the transform. The south wall of the transform at the western RTI consists of a diabase section near its base between 5000 and 4600 m depth overlain by basaltic lavas, with no evidence of gabbro or deeper crustal rocks. The south wall is undergoing normal faulting with considerable strike-slip component. The lavas of the neovolcanic zone at the RTI are highly magnetized (17 A m−1) compared to the lavas of the south wall (4 A m−1), consistent with their age difference. The trace of the active transform changes eastwards into a prominent median ridge, which is composed of heavily sedimented and highly serpentinized peridotites. Submersible observations made from SHINKAI find that the western RTI of the Kane transform has a very different seafloor morphology and lithology compared to the eastern RTI. Large rounded massifs exposing lower crustal rocks are found on the inside corner of the eastern RTI whereas volcanic ridge and valley terrain with hooked ridges are found on the outside corner of the eastern RTI. The western RTI is much less asymmetric with both inside and outside corner crust showing a preponderance of volcanic terrain. The dominance of low-angle detachment faulting at the eastern RTI has resulted in a seafloor morphology and architecture that is diagnostic of the process whereas crust formed at the WMARK RTI must clearly be operating under a different set of conditions that suppresses the initiation of such faulting.
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Allerton, S., Murton, B. J., Searle, R. C. and Jones, M.: 1995, 'Extensional faulting and segmentation of the Mid-Atlantic Ridge north of the Kane fracture zone, (24°00′ N to 24°40′ N)', Mar. Geophys. Res. 17: 37–61.
Auzende, J-M., Bideau, D., Bonatti, E., Cannat, M., Honnorez, J., Lagabrielle, Y., Malavieille, J., Mamaloukas-Frangoulis, V. and Mevel, C.: 1989, 'Direct observations of a section though slow-spreading oceanic crust', Nature 337: 726–729.
Auzende, J-M., Cannat, M., Gente, P., Henriet, J. P., Juteau, T., Karson, J., Lagabrielle, Y. and Tivey, M. A.: 1993, 'A transect through 0–4 Ma oceanic crust: NAUTILE dives along the Kane Transform', RIDGE Events 4: 1, 3.
Auzende, J-M., Cannat, M., Gente, P., Henriet, J. P., Juteau, T., Karson, J., Lagabrielle, Y., Mevel, C. and Tivey, M. A.: 1994, 'Observations of sections of oceanic crust and mantle cropping out on the southern wall of Kane FZ (N. Atlantic)', Terra Research 6: 143–148.
Barth, G. A., Kastens, K. A. and Klein, E. M.: 1994, 'The origin of bathymetric highs at ridge-transform intersections: a multi-disciplinary case study at the Clipperton fracture zone', Mar. Geophys. Res. 16: 1–50.
Bonatti, E.: 1978, 'Vertical tectonism in oceanic fracture zones', Earth Planet. Sci. Lett. 37: 369–379.
Brown, J. R. and Karson, J. A.: 1988, 'Variations in axial processes on the Mid-Atlantic Ridge: The median valley of the MARK area', Mar. Geophys. Res. 10: 109–138.
Cande, S. C. and Kent, D. V.: 1995, 'Revised calibration of the geomagnetic polarity timescale for the late Cretaceous and Cenozoic', J. Geophys. Res. 100: 6093–6095.
Cann, J. R., Blackman, D. K., Smith, D. K., McAllister, E., Janssen, B., Mello, S., Avgerinos, E., Pascoe, A. R. and Escartin, J.: 1997, 'Corrugated slip surfaces formed at ridge-transform intersections on the Mid-Atlantic Ridge', Nature 385: 329–332.
Cannat, M., Mevel, C., Maia, M., Deplus, C., Durand, C., Gente, P., Agrinier, P., Belarouchi, A., Dubuisson, G., Humler, E. and Reynolds, J.: 1995a, 'Thin crust, ultramafic exposures, and rugged faulting patterns at the Mid-Atlantic Ridge (22–24° N)', Geology 23: 49–52.
Cannat, M., Karson, J. A. and Miller, D. J. et al.: 1995b, Proc. Ocean Drilling Program, Init. Repts. 153: College Station, TX (Ocean Drilling Program).
Christie, D. M. and Sinton, J. M.: 1981, 'Evolution of abyssal lavas along propagating segments of the Galapagos spreading center', Earth Planet. Sci. Lett. 56: 321–335.
Collette, B. J. and Roest, W. R.: 1992, 'Further investigations of the North Atlantic between 10° and 40° N and an analysis of spreading from 118 Ma ago to present', Proc. Kon. Ned. Akad. v. Wetensch 95: 159–206.
Cormier, M.H., Detrick, R. S. and Purdy, G. M.: 1984, 'Anomalously thin crust in oceanic fracture zones: New seismic constraints from the Kane fracture zone', J. Geophys. Res. 89: 10249–10266.
Deplus, C., Maia, M., Aslanian, D. and Gente, P.: 1992, 'Segmentation of the Mid-Atlantic Ridge south of Kane FZ revealed by gravity anomalies: Results of SEADMA I cruise', EOS Trans. AGU 73(43): 568.
Detrick, R. S., and Purdy, G. M.: 1980, 'Crustal structure of the Kane fracture zone from seismic refraction studies', J. Geophys. Res. 85: 3759–3777.
Detrick, R. S., Fox, P. J., Kastens, K., Ryan, W. B. F., Mayer, L. and Karson, J. A.: 1984, 'A SeaBeam survey of the Kane Fracture Zone and adjacent Mid-Atlantic Ridge rift valley', EOS Trans. AGU 65(45): 1006.
Detrick, R., Honnorez, J., Bryan, W., Juteau, T. et al.: 1990, Proc. Ocean Drilling Prog. Init. Repts. 106/109, College Station, TX, ODP.
Dick, H. J. B., Schouten, H., Meyer, P., Gallo, D., Bergh, H., Tyce, R., Patriat, P., Johnson, K., Snow, J. and Fisher, A.: 1991, 'Tectonic evolution of the Atlantis II Fracture Zone', Proc. Ocean Drilling Program, edited by R.P. Von Herzen and P.T. Robinson, Scientific Results 118: 359–398.
Francheteau, J., Choukroune, P., Hekinian, R., Le Pichon, X. and Needham, H. D.: 1976, 'Oceanic fractures do not provide deep sections of the crust', Can. J. Earth Sci. 13: 1223–1235.
Fujimoto, H., Bryan, W. B., Matsumoto, T., Furuta, T., Fujiwara, T., Tivey, M., Lin, J., Kobayashi, K., Kinoshita, H., Takeuchi, A., Ishizuka, H., Kelemen, P., Hotta, H. and Purdy, M.: 1994, 'A geophysical survey of the mid-Atlantic Ridge around the western Kane Transform fault', EOS Trans. AGU 75: 44, 656.
Fujimoto, H., Bryan, W. B., Tivey, M., Kobayashi, K., Matsumoto, T., Kinoshita, H., Takeuchi, A., Ishizuka, H., Furuta, T. and Fujiwara, T: 1995, 'Outline of diving surveys in the WMARK area in the Atlantic', JAMSTEC J. Deep Sea Res. 11: 1–9.
Fujimoto, H., Bryan, W., Matsumoto, T. and Kobayashi, K.: 1996a, 'MODE 94 SHINKAI 6500 dives in WMARK area on the Mid-Atlantic Ridge', Cruise Rep. Fleet of JAMSTEC Deep Sea Res. 2: 241 pp.
Fujimoto, H., Seama, N., Lin, J., Matsumoto, T., Tanaka, T. and Fujioka, K.: 1996b, 'Gravity anomalies of the Mid-Atlantic ridge north of the Kane fracture zone', Geophys. Res. Lett. 23: 3431–3434.
Fujiwara, T. and Fujimoto, H.: 1998, 'Seafloor geomagnetic vector anomaly around the intersection of the Mid-Atlantic Ridge and the Kane transform fault: Implications for magnetization of the oceanic crust', J. Geophys. Res. 103: 30,335–30,349.
Gao, D., Hurst, S. D., Karson, J. A., Delaney, J. R. and Spiess, F. N.: 1998, 'Computer-aided interpretation of side-looking sonar images from the eastern intersection of the Mid-Atlantic Ridge with the Kane transform', J. Geophys. Res. 103: 20,997–21,014.
Gay, S. and Parker, Jr.: 1963, 'Standard curves for interpretation of magnetic anomalies over long tabular bodies', Geophysics 28: 161–200.
Gee, J. and Kent, D. V.: 1994, 'Variations in layer 2A thickness and the origin of the central anomaly magnetic high', Geophys. Res. Lett. 21: 297–300.
Gente, P. et al.: 1991, 'Geometry of past and present-day segmentation of the Mid-Atlantic Ridge south of Kane fracture zone', EOS Trans. AGU 72(44): 477.
Gente, P., Pockalny, R. A., Durand, C., Deplus, C., Maia, M., Ceuleneer, G., Mevel, C., Cannat, M. and Laverne, C.: 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: 55–71.
Grindlay, N. R., Fox, P. J. and Vogt, P. R.: 1992, 'Morphology and tectonics of the Mid-Atlantic Ridge (25°–27° 30'S) from Sea Beam and magnetic data', J. Geophys. Res. 97: 6983–7010.
Hussenoeder, S., Tivey, M. A., Schouten, H. and Searle, R.: 1996, 'Near-bottom magnetic survey of the Mid-Atlantic Ridge Axis, 24°–24°40′ N: Implications for crustal accretion at slow spreading ridges', J. Geophys. Res. 101: 22,051–22,069.
Johnson, H. P. and Pariso, J. E.: 1993, 'Variations in oceanic crustal magnetization: Systematic changes in the last 160 million years', J. Geophys. Res. 98: 435–446.
Karson, J. A. and Dick, H. J. B.: 1983, 'Tectonics of ridge-transform intersections at the Kane fracture zone', Mar. Geophys. Res. 6: 51–98.
Karson, J. A., Thompson, G., Humphris, S. E, Edmond, J. M., Bryan, W. B., Brown, J. R., Winters, A. T, Pockalny, R. A, Casey, J. F., Campbell, A. C, Klinkhammer, G., Palmer, M. R., Kinzler, R. J. and Sulanowska, M. M.: 1987, 'Along-axis variations in seafloor spreading in the MARK area', Nature 328: 681–685.
Karson, J. A.: 1991, 'Seafloor spreading on the Mid-Atlantic Ridge: Implications for the structure of ophiolites and oceanic lithosphere produced in slow-spreading environments', in Malpas, J., Moores, E. M., Panayiotou, A. and Xenophontos, C. (eds.), Proc. of the Symposium 'TROODOS 1987': Geol. Surv. Dept., Nicosia, Cyprus, 547–555.
Karson, J. A., Delaney, J. R, Spiess, F. N., Hurst, S., Lawhead, B., Naidoo, D. D. and Gente, P.: 1992, 'Deep-Tow operations at the eastern intersection of the Mid-Atlantic ridge and the Kane fracture zone', EOS Trans. AGU 73: 1992.
Karson, J. A. and Lawrence, R. M.: 1997, 'Tectonic window into gabbroic rocks of the middle oceanic crust in the MARK area near sites' 921–924, Proc. Ocean Drilling Program, Scientific Results 153: 61–76.
Karson, J. A., Cannat, M., Miller, D. J. and Elthon, D.: 1997, Proc. Ocean Drilling Program, Scientific Results: 153, College Station, TX, (ODP).
Kong, L. S., Detrick, R. S., Fox, P. J., Mayer, L. A. and Ryan, W. B.: 1988, 'The morphology and tectonics of the Mark area from Sea Beam and SeaMARC I observations (Mid-Atlantic Ridge 23° N)', Mar. Geophys. Res. 10: 59–90.
Lawson, K., Searle, R. C., Pearce, J. A., Browning, P. and Kempton, P.: 1996, 'Detailed volcanic geology of the MARNOK area, Mid-Atlantic Ridge north of Kane transform, in Tectonic, Magmatic, Hydrothermal and Biological segmentation of Mid-Ocean Ridges', edited by C. J. Macleod, Tyler, P. A. and Walker, C. L. Geol. Soc. Spec. Publ. 118: 61–102.
Luyendyk, B. P.: 1984, 'On bottom gravity profile across the East Pacific Rise at 21° north', Geophysics 49: 2166–2177.
Macdonald, K. C., Castillo, D. A., Miller, S. P., Fox, P. J., Kastens, K. A. and Bonatti, E.: 1986, 'Deep-tow studies of the Vema fracture zone 1. Tectonics of a major slow-slipping transform fault and its intersection with the Mid-Atlantic ridge', J. Geophys. Res. 91: 3334–3354.
Maia, M., and Gente, P.: 1998, '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.
Mevel, C., Cannat, M., Gente, P., Marion, E., Auzende, J.-M. and Karson, J. A.: 1991, 'Emplacement of deep crustal and mantle rocks on the west median valley wall of the MARK area (MAR 23° N)', Tectonophys. 190: 31–53.
Michael, P. J., Forsyth, D. W., Blackman, D. K., Fox, P. J., Hanan, B. B., Harding, A. J., Macdonald, K. C., Neumann, G. A., Orcutt, J. A., Tolstoy, M. and Weiland, C. M.: 1994, 'Mantle control of a dynamically evolving spreading center: Mid-Atlantic Ridge 31–34°S', Earth Planet. Sci. Lett. 121: 451–468.
Miyashiro, A., Shido, F. and Ewing, M.: 1969, 'Composition and origin of serpentinites from the Mid-Atlantic ridge near 24° and 30 ° North latitude', Contrib. Min. Petrol. 23: 17–127.
Miyashiro, A., Shido, F. and Ewing, M.: 1971, 'Metamorphism in the Mid-Atlantic Ridge near 24° and 30° N,' Phil. Trans. Roy. Soc. London (A) 268: 589–603.
Morris, E., and Detrick, R. S.: 1991, 'Three-dimensional analysis of gravity anomalies in the MARK area, Mid-Atlantic Ridge 23° N', J. Geophys. Res. 96: 4355–4366.
Niu, Y. and Batiza, R.: 1994, 'Magmatic processes at a slow spreading ridge', J. Geophys. Res. 99: 19,719–19,740.
OTTER Team: 1984, 'The geology of the Oceanographer transform: The ridge-transform intersection', Mar. Geophys. Res. 6: 109–141.
Pedersen, L. B.: 1978, 'A statistical analysis of potential fields using a vertical cylinder and a dike', Geophysics 43: 943–953.
Pockalny, R. A., Detrick, R. S. and Fox, P. J.: 1988, 'Morphology and tectonics of the Kane transform from Sea Beam bathymetric data', J. Geophys. Res. 93: 3179–3193.
Pockalny, R. A., Smith, A. and Gente, P.: 1995, 'Spatial and temporal variability of crustal magnetization of a slowly spreading ridge: Mid-Atlantic Ridge (20°–24° N)', Mar. Geophys. Res. 17: 301–320.
Sayanagi, K., Fujimoto, H., Tamaki, K., Fujiwara, T., Murakami, H. and Minoshima, K.: 1995, 'Development of new versatile deep-sea three component magnetometer system', J. Japan Soc. Mar. Surv. Tech. 6: 21–32.
Schulz, N. J., Detrick, R. S. and Miller, S. P.: 1988, 'Two-and three-dimensional inversions of magnetic anomalies in the MARK area (Mid-Atlantic Ridge, 23° N)', Mar. Geophys. Res. 10: 41–57.
Sempere, J.-C., Purdy, G. M. and Schouten, H.: 1993, 'Segmentation of the Mid-Atlantic Ridge between 24° N and 30°40′ N', Nature 344: 427–431.
Sempere, J-C., Lin, J., Brown, H. S., Schouten, H. and Purdy, G. M.: 1993, 'Segmentation and morphotectonic variations along a slow-spreading center: the Mid-Atlantic Ridge (24°00′ N–30°40′ N)', Mar. Geophys. Res. 15: 153–200.
Severinghaus, J. P. and Macdonald, K. C.: 1988, 'High inside corners at ridge transform intersections', Mar. Geophys. Res. 9: 353–367.
Sinton, J. M. and Detrick, R. S.: 1992, 'Mid-ocean ridge magma chambers', J. Geophys. Res. 97: 197–216.
Smith, D. K. and Cann, J.: 1992, 'The role of seamount volcanism in crustal construction at the Mid-Atlantic Ridge (24°–30° N)', J. Geophys. Res. 97: 1645–1658.
Tivey, M. A., Rona, P. A. and Schouten, H.: 1993, 'Reduced crustal magnetization beneath the active sulfide mound, TAG Hydrothermal Field, Mid-Atlantic Ridge 26° N', Earth Planet. Sci. Lett. 115: 101–116.
Tivey, M. A.: 1996, 'The vertical magnetic structure of ocean crust determined from near-bottom magnetic field measurements', J. Geophys. Res. 101: 20,275–20,296.
Tivey, M. A. and Tucholke, B. E., 1998, 'Magnetization of oceanic crust from 0 to 29 Ma formed at the Mid-Atlantic Ridge 25°30′ to 27°10′ N', J. Geophys. Res. 103: 17,807–17,826.
Tucholke, B. E. and Schouten, H.: 1988, Kane Fracture Zone, Mar. Geophys. Res. 10: 1–39.
Tucholke, B. E. and Lin, J.: 1994, 'A geological model for the structure of ridge segment in slow spreading ocean crust', J. Geophys. Res. 99: 11,937–11,958.
Tucholke, B. E., Lin, J. and Kleinrock, M. C.: 1998, 'Megamullions and mullion structure defining oceanic metamorphic core complexes on the Mid-Atlantic Ridge', J. Geophys. Res. 103: 9857–9866.
Weiland, C., Macdonald, K. and Grindlay, N.: 1996, 'Ridge segmentation and the magnetic structure of the Southern Mid-Atlantic ridge 26°S and 31°–35°S: Implications for magmatic processes at slow spreading centers', J. Geophys. Res. 101: 8055–8073.
Wilcock, W. S., Purdy, G. M. and Solomon, S. C.: 1990, 'Micro earthquake evidence for extension across the Kane Transform fault', J. Geophys. Res. 95: 15,439–15,462.
Zonenshain, L. P., and Kuzmin, M. I., Lisitsin, A. P., Bogdanov, Yu. A. and Baranov, B. V.: 1989, 'Tectonics of the Mid-Atlantic rift valley between the TAG and MARK areas (26–24° N): evidence for vertical tectonism', Tectonophysics 159: 1–23.
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Tivey, M., Takeuchi, A. & Scientific Party, W. A submersible study of the western intersection of the Mid-Atlantic ridge and Kane fracture zone (WMARK). Marine Geophysical Researches 20, 195–218 (1998). https://doi.org/10.1023/A:1004630501837
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DOI: https://doi.org/10.1023/A:1004630501837