Dynamical Instability Produces Transform Faults at Mid-Ocean Ridges

  title={Dynamical Instability Produces Transform Faults at Mid-Ocean Ridges},
  author={Taras V. Gerya},
  pages={1047 - 1050}
  • T. Gerya
  • Published 2010
  • Geology, Medicine
  • Science
Cracking Up Transform faults perpendicular to mid-ocean ridges are some of the most prominently visual features on the sea floor. Because they form slowly over thousands of years, the lack of observational data means their mechanism of formation has remained controversial. Taking a numerical modeling approach, Gerya (p. 1047) suggests that due to asymmetric growth of the plate boundary, sections of the mid-ocean ridge become unstable and eventually rotate 90°. As the ridge continues to grow… Expand
Origin and models of oceanic transform faults
Abstract Mid-ocean ridges sectioned by transform faults represent prominent surface expressions of plate tectonics. A fundamental problem of plate tectonics is how this pattern has formed and why itExpand
Initiation of a Proto-transform Fault Prior to Seafloor Spreading
Transform faults are a fundamental tenet of plate tectonics, connecting offset extensional segments of mid‐ocean ridges in ocean basins worldwide. The current consensus is that oceanic transformExpand
Seafloor expression of oceanic detachment faulting reflects gradients in mid-ocean ridge magma supply
Abstract Oceanic detachment faulting is a major mode of seafloor accretion at slow and ultraslow spreading mid-ocean ridges, and is associated with dramatic changes in seafloor morphology.Expand
Porosity‐driven convection and asymmetry beneath mid‐ocean ridges
Seismic tomography of the asthenosphere beneath mid-ocean ridges has produced images of wave speed and anisotropy that are asymmetric across the ridge axis. These features have been interpreted asExpand
Oblique continental rifting and long transform fault formation based on 3D thermomechanical numerical modeling
Abstract The length of oceanic transform faults is highly variable in nature and can range from zero-offset fracture zones to longer than thousand kilometers. The initiation and evolution ofExpand
Rheological control on the segmentation of the mid-ocean ridges: Laboratory experiments with extension initially perpendicular to the axis
Abstract Mid-ocean ridges (MOR) axes are not straight, but segmented over scales of 10s to 100s of kilometers by several types of offsets including transform faults (TF), overlapping spreadingExpand
Initiation of transform faults at rifted continental margins: 3D petrological-thermomechanical modeling and comparison to the Woodlark Basin
This work presents high-resolution 3D numerical model of transform fault initiation at rifted continental margins. Our petrological-thermomechanical visco-plastic model allows for spontaneousExpand
Accretion mode of oceanic ridges governed by axial mechanical strength
Oceanic spreading ridges exhibit structural changes as a function of spreading rate, mantle temperature and the balance of tectonic and magmatic accretion. The role that these or other processes haveExpand
Origin and model of transform faults in the Okinawa Trough
Transform faults in back-arc basins are the key to revealing the opening and development of marginal seas. The Okinawa Trough (OT) represents an incipient and active back-arc or marginal sea basinExpand
Mechanical and geological controls on the long-term evolution of normal faults
This thesis investigates the long-term evolution of rift-bounding normal faults. To first order, the observed diversity of extensional tectonic styles reflects differences in the maximum offset thatExpand


Modes of faulting at mid-ocean ridges
Numerical models of plate separation, dyke intrusion and faulting require at least two distinct mechanisms of fault formation at ridges to explain a large range of fault sizes and orientations. Expand
Spreading rate dependence of gravity anomalies along oceanic transform faults
A systematic study of the residual mantle Bouguer gravity anomaly of 19 oceanic transform faults reveals a strong correlation between gravity signature and spreading rate, which suggests that three-dimensional magma accretion may occur near intermediate- and fast-slipping transform faults. Expand
Evidence for weak oceanic transform faults
[1] We present the results of a series of 3-D boundary element calculations to investigate the effects of oceanic transform faults on stress state and fault development at adjacent mid-ocean ridgeExpand
Central role of detachment faults in accretion of slow-spreading oceanic lithosphere
An examination of ∼2,500 km of the Mid-Atlantic Ridge between 12.5 and 35° N is presented, which reveals asymmetrical accretion along almost half of the ridge, suggesting that much of the variability in sea-floor morphology, seismicity and basalt chemistry found along slow-spreading ridges can be thus attributed to the frequent involvement of detachment faults in oceanic lithospheric accretion. Expand
Thermal stress and the spacings of transform faults
Bathymetric charts are used with satellite altimeter profiles to locate major ridge-transform intersections along five spreading ridges. The ridges are the Mid-Atlantic Ridge, the East Pacific Rise,Expand
Stress fields associated with oceanic transform faults
Abstract Although their formation is commonly attributed to shear stresses, oceanic transform faults contain many structural elements indicating extension across them. Examples includeExpand
A tectonic model for ridge-transform-ridge plate boundaries: implications for the structure of oceanic lithosphere
Abstract The first-order geologic and morphologic relationships at, along and proximal to ridge-transform-ridge plate boundaries are used to construct an empirical and speculative tectonic model. TheExpand
Extremely asymmetric magmatic accretion of oceanic crust at the ends of slow-spreading ridge segments
We report the results of a deep-towed magnetic survey of part of a Mid-Atlantic Ridge spreading segment. Analysis of the magnetic reversals indicates that for the past 0.7 m.y., magmatic accretion atExpand
An ultraslow-spreading class of ocean ridge
An ultraslow-spreading class of ocean ridge that is characterized by intermittent volcanism and a lack of transform faults is revealed, and it is found that the mantle beneath such ridges is emplaced continuously to the seafloor over large regions. Expand
Thermomechanics of mid-ocean ridge segmentation
The mechanics responsible for the initiation of the orthogonal pattern characterizing mid-ocean ridges and transform faults are studied using numerical models. The driving forces are thermal stressesExpand