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Fault scarp statistics at the Galapagos spreading centre from Deep Tow data

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Abstract

Much of the relief of the abyssal hills covering the ocean basins is believed to originate from faulting of oceanic crust at mid-ocean ridges. The timescale over which faults grow is controversial, however, with some authors arguing that faults continue to grow in places for 0.5 m.y. or more based on increasing relief of fault scarps with distance from ridge axes. We examine Deep Tow profiler records of the Galapagos Spreading Centre, in which basement reflections allow scarp relief to be measured beneath the sediment cover, and find that relief does not increase but decreases systematically to 40 km off-axis (1.5 Ma seafloor). Since reversal of fault offsets is unlikely in this tectonic setting, we interpret this result as indicating that variations in fault statistics could reflect temporal variations in the tectonic or volcanic state of the ridge crest, not necessarily progressive fault growth with age as previously assumed. Resolving the issue of fault longevity will therefore require independent data on the timing of fault growth and distribution of present growth activity. We suggest some possible alternative indicators of fault longevity and discuss more generally the implications of volcanic flows to studies of faulting at ridges.

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References

  • Alexander, R. T. and Macdonald, K. C., 1996, Sea Beam, Sea-MARC II and ALVIN-based studies of faulting on the East Pacific Rise 9°20′N–9°50′N, Marine Geophys. Res. 18: 557–587.

    Google Scholar 

  • Allmendinger, R. W. and Riis, F., 1979, The Galapagos Rift at 86°W, regional morphological and structural analysis, J. Geophys. Res. 84: 5379–5389.

    Google Scholar 

  • Ballard, R. D., Holcomb, R. T. and van Andel, T. H., 1979. The Galapagos Rift at 86°W: 3. Sheet flows, collapse pits, and lava lakes of the rift valley. J. Geophys. Res. 84: 5407–5422.

    Google Scholar 

  • Ballard, R. D., van Andel, T. H. and Holcomb, R. T., 1982, The Galapagos Rift at 86 deg W. 5. Variation in volcanism, structure, and hydrothermal activity along a 30-km segment of the rift valley, J. Geophys. Res. 87: 1149–1161.

    Google Scholar 

  • Bergman, E. A. and Solomon, S. C., 1984, Source machanisms of earthquakes near mid-ocean ridges from body waveform inversion: implications for the early evolution of oceanic lithosphere, J. Geophys. Res. 89: 11415–11441.

    Google Scholar 

  • Bicknell, J. D., Sempere, J.-C., Macdonald, K. C. and Fox, P. J., 1987, Tectonics of a fast-spreading center: A deep-tow and Sea Beam survey on the East Pacific Rise at 19°30′S, Marine Geophys. Res. 9: 25–45.

    Google Scholar 

  • Bratt, S. R., Bergman, E. A. and Solomon, S. C., 1985, Thermoelastic stress: how important as a cause of earthquakes in young oceanic lithosphere?, J. Geophys. Res. 90: 10249–10260.

    Google Scholar 

  • 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.

    Google Scholar 

  • Carbotte, S. M. and Macdonald, K. C., 1994, Comparison of seafloor tectonic fabric at intermediate, fast, and super fast spreading rates: Influence of spreading rate, plate motions, and ridge segmentation on fault patterns, J. Geophys. Res. 99: 13609–13631.

    Google Scholar 

  • Choukroune, P., Francheteau, J. and Hekinian, R., 1984, Tectonics of the East Pacific Rise near 12° 50′N: A submersible study, Earth Planet. Sc. Lett. 68: 115–127.

    Google Scholar 

  • Clay, C. S. and Medwin, H., 1977. Acoustical oceanography: principles and applications. Wiley Interscience, New York, 544 pp.

    Google Scholar 

  • Cowie, P. A., Malinverno, A., Ryan, W. B. F. and Edwards, M. H., 1994, Quantitative fault studies on the East Pacific Rise &3-a comparison of sonar imaging techniques, J. Geophys. Res. 99: 15205–15218.

    Google Scholar 

  • Cowie, P. A., Scholz, C. H., Edwards, M. and Malinverno, A., 1993, Fault strain and seismic coupling on mid-ocean ridges, J. Geophys. Res. 948: 17911–17920.

    Google Scholar 

  • CYAMEX, scientific team:, Francheteau, J., Needham, H. D., Choukroune, P., Juteau, T., Seguret, M., Ballard, R. D., Fox, P. J., Normark, W. R., Carranza, A., Cordoba, D., Guerrero, J. and Rangin, C., 1981, The first manned submersible dives on the East Pacific Rise at 21°N (project RITA): General results, Marine Geophys. Res. 4: 345–379.

    Google Scholar 

  • Edwards, M. H., Fornari, D. J., Malinverno, A., Ryan, W. B. F. and Madsen, J., 1991, The regional tectonic fabric of the East Pacific Rise from 12° 50′N to 15° 10′N, J. Geophys. Res. 96: 7995–8017.

    Google Scholar 

  • Fang, W. W., Langseth, M. G. and Schultheiss, P. J., 1993, Analysis and application of in situ pore pressure measurments in marine sediments, J. Geophys. Res. 98: 7921–7938.

    Google Scholar 

  • Hey, R. N., Duennebier, F. and Morgan, W. J., 1980, Propagating rifts on mid-ocean ridges, J. Geophys. Res. 85: 3647–3658.

    Google Scholar 

  • Hsu, K. J., 1975, Catastrophic debris streams (Sturzstroms) generated by rockfalls, Geol. Soc. Am. Bull. 86: 129–140.

    Google Scholar 

  • Ito, G. T. and Lin, J., 1995, Mantle temperature anomalies along the past and paleoaxes of the Galapagos spreading center as inferred from gravity analyses, J. Geophys. Res. 100: 3733–3745.

    Google Scholar 

  • Karato, S. and Becker, K., 1983, Physical properties of sediments from the Galapagos region and their implications for hydrothermal convection, in J. Honnorez, R. P. Von Herzen et al. (eds.), Init. Repts. DSDP, vol. 70, U.S. Govt. Printing Office, Washington, pp. 355–368.

    Google Scholar 

  • Kastens, K. A., 1984, Earthquakes as a triggering mechanism for debris flows and turbidites on the Calabrian Ridge, Mar. Geol. 55: 13–33.

    Google Scholar 

  • Kent, G. M., Swift, S. A., Detrick, R. S., Collins, J. A., and Stephen, R. A., 1996, Evidence for active normal faulting on 5.9 Ma old crust near Hole 504B on the southern flank of the Costa Rica Rift, Geology 24: 83–86.

    Google Scholar 

  • Klitgord, K. D. and Mudie, J. D., 1974, The Galapagos spreading centre: a near-bottom geophysical survey, Geophys. J. R. astr. Soc. 38: 563–586.

    Google Scholar 

  • Laughton, A. S. and Searle, R. C., 1979, Tectonic processes on slow spreading ridges, in M. Talwani, C. G. Harrison and D. E. Hayes (eds.), Deep Drilling Results in the Atlantic Ocean: Ocean Crust, Maurice Ewing Series, vol. 2, American Geophysical Union, Washington, D. C., pp. 15–32.

    Google Scholar 

  • Lee, S.-M. and Solomon, S. C., 1995, Constraints from Sea Beam bathymetry on the development of normal faults on the East Pacific Rise, Geophys. Res. Lett. 22: 3135–3139.

    Google Scholar 

  • Lonsdale, P., 1977a, Deep-tow observations at the mounds abyssal hydrothermal field, Galapagos Rift, Earth Planet. Sci. Lett. 36: 92–110.

    Google Scholar 

  • Lonsdale, P., 1977b, Structural geomorphology of a fast-spreading rise crest: the East Pacific Rise near 3° 25′S, Marine Geophys. Res. 3: 251–293.

    Google Scholar 

  • Macdonald, K. C., Fox, P. J., Alexander, R. T., Pockalny, R. and Gente, P., 1996, Volcanic growth faults and the origin of Pacific abyssal hills, Nature 380: 125–129.

    Google Scholar 

  • Macdonald, K. C., Haymon, R. and Shor, A., 1989, A 220 km2 recently erupted lava field on the East Pacific Rise near lat 8°S, Geology 17: 212–216.

    Google Scholar 

  • Macdonald, K. C. and Luyendyk, B. P., 1985, Investigation of faulting and Abyssal hill formation on the flanks of the East Pacific Rise (21°N) using ALVIN, Marine Geophys. Res. 7: 515–535.

    Google Scholar 

  • McAllister, E., 1995, Tectonic processes on the Mid-Atlantic Ridge, Ph. D., University of Leeds, U.K., pp. McAllister, E., Spencer, S. and Dougherty, M., 1993, Observations of mass-wasting in the crestal mountains of the MAR: implications for the seismic life of a crestal mountain fault, Bridge Newsletter 4: 7–12.

    Google Scholar 

  • Mitchell, N. C., 1991, Improving GLORIA images using Sea Beam data, J. Geophys. Res. 96: 337–351.

    Google Scholar 

  • Mitchell, N. C., 1993, A model for attenuation of backscatter due to sediment accumulations and its application to determine sediment thickness with GLORIA sidescan sonar, J. Geophys. Res. 98: 22477–22493.

    Google Scholar 

  • Mitchell, N. C., 1995, Characterising the extent of volcanism at the Galapagos Spreading Centre using Deep Tow profiler records, Earth Planet. Sci. Lett. 134: 459–472.

    Google Scholar 

  • Mitchell, N. C., 1996, Creep in pelagic sediments and potential for morphologic dating of marine fault scarps, Geophys. Res. Lett. 23: 483–486.

    Google Scholar 

  • Mitchell, N. C., 1998, Sediment accumulation rates from Deep Tow profiler records and DSDP Leg 70 cores over the Galapagos Spreading Centre, in A. Cramp, C. J. MacLeod, S. V. Lee and E. J. W. Jones (eds.), Geological Evolution of Ocean Basins: Results From the Ocean Drilling Program, Geol Soc spec publ., vol. 131, Geological Society, London, pp. 199–209.

    Google Scholar 

  • Morgenstern, N. R., 1967, Submarine slumping and the initiation of turbidity currents, in A. F. Richards (ed.) Marine Geotechnique, Univ. of Ill. Press, Urbana, pp. 189–210.

    Google Scholar 

  • Muller, R. D., Roest, W. R., Roger, J.-Y., Gahagan, L. M., and Sclater, J. G., 1997, Digital isochrons of the world's ocean floor, J. Geophys. Res. 102: 3211–3214.

    Google Scholar 

  • Pezard, P. A. et al., 1995. Fractures, faults and tectonic stress in the upper oceanic crust from ODP core and downhole measurements. EOS, Trans. Am. Geophys. Union (Fall Meet. Suppl.) 76(46): p. F325.

    Google Scholar 

  • Rea, D. K., 1975, Model for the formation of topographic features of the East Pacific Rise, Geology 3: 77–80.

    Google Scholar 

  • Searle, R. C., 1984, GLORIA survey of the East Pacific Rise near 3.5°S: tectonic and volcanic characteristics of a fast spreading mid-ocean rise, Tectonophysics 101: 319–344.

    Google Scholar 

  • Searle, R. C., Francis, T. J. G., Hilde, T. W. C., Somers, M. L., Revie, J., Jacobs, C. L., Saunders, M. R., Barrow, B. J. and Bicknell, S. V., 1981, 'Gloria' side-scan sonar in the East Pacific, EOS Trans. Am. Geophys. Union 62: 121–122.

    Google Scholar 

  • Searle, R. C. and Hey, R. N., 1983, Gloria observations of the propagating rift at 95.5°W on the Cocos-Nazca spreading center, J. Geophys. Res. 88: 6433–6447.

    Google Scholar 

  • Searle, R. C. and Laughton, A. S., 1977, Sonar studies of the Mid-Atlantic Ridge and Kurchatov Fracture Zone, J. Geophys. Res. 82: 5313–5328.

    Google Scholar 

  • Skempton, A. W., 1970, The consolidation of clays by gravitational compaction, Q. J. Geol. Soc. London 125: 373–411.

    Google Scholar 

  • Somers, M. L., Carson, R. M., Revie, J. A., Edge, R. H., Barrow, B. J. and Andrews, A. G., 1978, Gloria II — an improved long range sidescan sonar, Institute of Electrical Engineers, New York, London, pp. 16–24.

    Google Scholar 

  • Spiess, F. N. and Lonsdale, P. F., 1982, Deep Tow Rise Crest Exploration Techniques, Mar. Tech. Soc. J. 16: 67–74.

    Google Scholar 

  • Spudich, P. and Orcutt, J., 1982, Estimation of earthquake ground motions relevant to the triggering of marine mass movements, in S. Saxov and J. K. Nieuwenhuis (eds.), Marine slides and other mass movements, Plenum Press, New York.

    Google Scholar 

  • Tivey, M. A., Johnson, H. P., Bradley, A. and Yoerger, D., 1998, Thickness of a submarine lava flow determined from near-bottom magnetic field mapping by autonomous underwater vehicle, Geophys. Res. Lett. 25: 805–808.

    Google Scholar 

  • van Andel, T. H. and Ballard, R. D., 1979, The Galapagos Rift at 86°W. 2. Volcanism, structure and evolution of the rift valley, J. Geophys. Res. 84: 5390–5406.

    Google Scholar 

  • Wessel, P. and Smith, W. H. F., 1991. Free software helps map and display data. EOS Trans. AGU, 72: 441. Westaway, R. and Smith, R. B., 1989, Strong ground motion in normal-faulting earthquakes, Geophys. J. 96: 529–559.

    Google Scholar 

  • Wetzel, A., 1989, Influence of heat flow on ooze/chalk cementation: Quantification from consolidation parameters in DSDP Sites 504 and 505 sediments, J. Sed. Petrol. 59: 539–547.

    Google Scholar 

  • Wilcock, W. S. D., Purdy, G. M., Solomon, S. C. and DuBois, D. L., 1992, Microearthquakes on and near the East Pacific Rise, 9°–10°N, Geophys. Res. Lett. 19: 2131–2134.

    Google Scholar 

  • Wilkens, R. H. and Langseth, M. G., 1983, Physical properties of sediments of the Costa Rica rift, Deep Sea Drilling Project site 504 and 505, in J. R. Cann, M. G. Langseth, J. Honnorez, R. P. Von Herzen, S. M. White et al. (eds.), Init. Repts. DSDP, Vol. 69, U.S. Govt. Printing Office, Washington, pp 659–673.

    Google Scholar 

  • Wilson, D. S. and Hey, R. N., 1995, History of rift propagation and magnetization intensity for the Cocos-Nazca spreading center, J. Geophys. Res. 100: 10,041–10,056.

    Google Scholar 

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Mitchell, N.C., Searle, R.C. Fault scarp statistics at the Galapagos spreading centre from Deep Tow data. Marine Geophysical Researches 20, 183–193 (1998). https://doi.org/10.1023/A:1004556813514

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