Modes of faulting at mid-ocean ridges

Publication Type  Journal Article
Year of Publication  2005
Authors  Buck, W. R.; Lavier, L. L.; Poliakov, A. N. B.
Journal Title  Nature
Volume  434
Issue  7034
Pages  719-723
Journal Date  Apr 7
ISBN Number  0028-0836
Accession Number  ISI:000228160700030
Key Words  east pacific rise; mid-atlantic ridge; seismic structure; spreading ridges; oceanic-crust; abyssal hills; seamarc-ii; sea-beam; lithosphere; floor

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.


913NUTimes Cited:13Cited References Count:42

URL  <Go to ISI>://000228160700030
DOI  Doi 10.1038/Nature03358