Abstract
Abyssal-hill-bounding faults that pervade the oceanic crust are the most common tectonic feature on the surface of the Earth. The recognition that these faults form at plate spreading centres came with the plate tectonic revolution. Recent observations reveal a large range of fault sizes and orientations; numerical models of plate separation, dyke intrusion and faulting require at least two distinct mechanisms of fault formation at ridges to explain these observations. Plate unbending with distance from the top of an axial high reproduces the observed dip directions and offsets of faults formed at fast-spreading centres. Conversely, plate stretching, with differing amounts of constant-rate magmatic dyke intrusion, can explain the great variety of fault offset seen at slow-spreading ridges. Very-large-offset normal faults only form when about half the plate separation at a ridge is accommodated by dyke intrusion.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Hannington, M. D., Jonasson, I. R., Herzig, P. M. & Petersen, S. in Seafloor Hydrothermal Systems; Physical, Chemical, Biological, and Geological Interactions (eds Humphris, S. E., Zierenberg, R. A., Mullineaux, L. S. & Thomson, R. E.) 115–157 (American Geophysical Union, Washington DC, 1995)
Van Dover, C. L. Evolution and biogeography of deep-sea vent and seep invertebrates. Science 295, 1253–1257 (2002)
Heezen, B. C. The rift in the ocean floor. Sci. Am. 203, 99–106 (1960)
Tapponnier, P. & Francheteau, J. Necking of the lithosphere and the mechanics of slowly accreting plate boundaries. J. Geophys. Res. 83, 3955–3970 (1978)
Lin, J. & Parmentier, E. M. A finite amplitude necking model of rifting in brittle lithosphere. J. Geophys. Res. 95, 4909–4923 (1990)
Poliakov, A. N. B. & Buck, W. R. in Faulting and Magmatism at Mid-Ocean Ridges (eds Buck, W. R., Delaney, P. T., Karson, J. A. & Lagabrielle, Y.) 305–324 (American Geophysical Union, Washington DC, 1998)
Price, N. J. & Cosgrove, J. W. Analysis of Geological Structures 1–452 (Cambridge Univ. Press, Cambridge, UK, 1990)
Thatcher, W. & Hill, D. P. A simple model for fault generated morphology of slow-spreading mid-oceanic ridges. J. Geophys. Res. 100, 561–570 (1995)
Carbotte, S. M. & Macdonald, K. C. Causes of variation in fault-facing direction on the ocean floor. Geology 18, 749–752 (1990)
Macdonald, K. C., Fox, P. J., Alexander, R. T., Pockalny, R. & Gente, P. Volcanic growth faults and the origin of the Pacific abyssal hills. Nature 380, 125–129 (1996)
Detrick, R. S. et al. Multichannel seismic imaging of the crustal magma chamber along the East Pacific Rise. Nature 326, 35–41 (1987)
Vera, E. E. et al. 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, 15529–15556 (1990)
Dunn, R. A. et al. Three-dimensional seismic structure and physical properties of the crust and shallow mantle beneath the East Pacific Rise at 9N. J. Geophys. Res. 105, 23537–23556 (2000)
Karson, J. A. et al. Structure of the uppermost fast-spread oceanic crust exposed at the Hess deep: Implications for subaxial processes at the East Pacific Rise. Geochem. Geophys. Geosyst. 2, 1002, doi:10.1029/2001GC000155 (2001)
Alexander, R. T. & Macdonald, K. C. Sea Beam, Sea MARC II and ALVIN based studies of faulting on the East Pacific Rise 9°20′ N-9°50′ N. Mar. Geophys. Res. 18, 557–587 (1996)
Karson, J. A. et al. Along-axis variations in seafloor spreading in the MARK area. Nature 328, 681–685 (1987)
Cann, J. R. et al. Corrugated slip surfaces formed at ridge-transform intersections on the Mid-Atlantic Ridge. Nature 385, 329–332 (1997)
Tucholke, B. E., Lin, J. & Kleinrock, M. Megamullions and mullion structure defining oceanic metamorphic core complexes on the Mid-Atlantic Ridge. J. Geophys. Res. 103, 9857–9866 (1998)
Blackman, D. K. et al. Geology of the Atlantis Massif (MAR 30°N): Implications for the evolution of an ultramafic core complex. Mar. Geophys. Res. 23, 443–469 (2004)
Tucholke, B. E. & Lin, J. A geologic model for the structure of ridge segments in slow-spreading ocean crust. J. Geophys. Res. 99, 11937–11958 (1994)
Crawford, W. C., Webb, S. C. & Hildebrand, J. A. Estimation of shear velocities in the oceanic crust from compliance measurements by two-dimensional finite difference modeling. J. Geophys. Res. 103, 9895–9916 (1998)
Purdy, G. M., Kong, L. S. L., Christeson, G. L. & Solomon, S. C. Relationship between spreading rate and the seismic structure of mid-ocean ridges. Nature 355, 815–817 (1992)
Phipps Morgan, J. & Chen, Y. J. The genesis of oceanic crust: magma injection, hydrothermal circulation and crustal flow. J. Geophys. Res. 98, 6283–6297 (1993)
Barclay, A. H., Toomey, D. R. & Solomon, S. C. Microearthquake characteristics and crustal VP/VS structure at the Mid-Atlantic Ridge, 35°N. J. Geophys. Res. 106, 2017–2034 (2001)
Buck, W. R. Accretional curvature of lithosphere at magmatic spreading centers and the flexural support of axial highs. J. Geophys. Res. 106, 3953–3960 (2001)
Shah, A. & Buck, W. R. Causes for axial high topography at mid-ocean ridges and the role of crustal thermal structure. J. Geophys. Res. 106, 30865–30880 (2001)
Kuo, B. Y., Forsyth, D. W. & Parmentier, E. M. Flexure and thickening of the lithosphere at the East Pacific Rise. Geophys. Res. Lett. 13, 681–684 (1986)
Eberle, M. A. & Forsyth, D. W. An alternative, dynamic model of the axial topographic high at fast spreading ridges. J. Geophys. Res. 103, 12309–12320 (1998)
Hooft, E. E., Detrick, R. S. & Kent, G. M. Seismic structure and indicators of magma budget along the Southern East Pacific Rise. J. Geophys. Res. 102, 27319–27340 (1997)
Buck, W. R. & Poliakov, A. N. B. Abyssal hills formed by stretching oceanic lithosphere. Nature 392, 272–275 (1998)
Einarsson, P. & Brandsdottir, B. Seismological evidence for lateral magma intrusion during the July 1978 deflation of the Krafla volcano in NE-Iceland. J. Geophys. 47, 160–165 (1980)
Magde, L. & Sparks, D. W. Three dimensional mantle upwelling, melt generation and melt migration beneath segmented slow spreading ridges. J. Geophys. Res. 102, 20571–20583 (1997)
Lavier, L. L., Buck, W. R. & Poliakov, A. N. B. Factors controlling normal fault offset in an ideal brittle layer. J. Geophys. Res. 105, 23431–23442 (2000)
Buck, W. R. Effect of lithospheric thickness on the formation of high- and low-angle normal faults. Geology 21, 933–936 (1993)
Lavier, L. L. & Buck, W. R. Half graben versus large-offset low-angle normal fault: The importance of keeping cool during normal faulting. J. Geophys. Res. 107, 10.1029/2001JB000513 (2002)
Dick, H. J. B., Lin, J. & Schouten, H. An ultraslow-spreading class of ocean ridge. Nature 426, 405–412 (2003)
Cochran, J. R., Kurras, G. H., Edwards, M. H. & Coakley, B. J. The Gakkel Ridge: Bathymetry, gravity anomalies and crustal accretion at extremely slow spreading rates. J. Geophys. Res. 108, doi:10.1029/2002JB001830 (2003)
Michael, P. J. et al. Magmatic and amagmatic seafloor generation at the ultraslow-spreading Gakkel Ridge, Arctic Ocean. Nature 423, 956–961 (2003)
Haxby, W. GeoMapApp version 1.2_02; http://www.GeoMapApp.org/ (Marine Geosciences Data Management System, downloaded August 2004).
Cochran, J. R. et al. The Southeast Indian Ridge between 88°E and 120°E: Gravity anomalies and crustal accretion at intermediate spreading rates. J. Geophys. Res. 102, 15463–15487 (1997)
Macdonald, K. C. et al. The East Pacific Rise and its flanks, 8–18°N: History of segmentation, propagation and spreading direction based on SeaMARC II and SeaBeam studies. Mar. Geophys. Res. 14, 299–344 (1992)
Gente, P. et al. Characteristics and evolution of the segmentation of the Mid-Atlantic Ridge between 20 degrees N and 24 degrees N during the last 10 million years. Earth Planet. Sci. Lett. 129, 55–71 (1995)
Acknowledgements
Work supported by the National Science Foundation. We thank W. Haxby for help with images and J. Karson for comments on the text.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Competing interests
The authors declare that they have no competing financial interests.
Supplementary information
Supplementary Material
Contains details of the numerical model of dyking and stretching. (DOC 29 kb)
Rights and permissions
About this article
Cite this article
Buck, W., Lavier, L. & Poliakov, A. Modes of faulting at mid-ocean ridges. Nature 434, 719–723 (2005). https://doi.org/10.1038/nature03358
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/nature03358
This article is cited by
-
Geophysical investigation of the Mado Megamullion oceanic core complex: implications for the end of back-arc spreading
Progress in Earth and Planetary Science (2023)
-
How transform fault shear influences where detachment faults form near mid-ocean ridges
Scientific Reports (2023)
-
Microseismicity and lithosphere thickness at a nearly-amagmatic oceanic detachment fault system
Nature Communications (2023)
-
Sulfide metallogenic model for the ultraslow-spreading Southwest Indian Ridge
Science China Earth Sciences (2023)
-
Neogene and Quaternary dikes and related joints as conduits for recent juvenile degassing: case studies from the seismically active region of NW-Bohemia, Czech Republic
Bulletin of Volcanology (2023)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.