论文信息 - Fast rift propagation at a slow-spreading ridge

Fast rift propagation at a slow-spreading ridge

Bathymetric, magnetic, gravity, and morphologic data from the flank of the slow-spreading Mid-Atlantic Ridge reveal obliquely oriented features that offset magnetic isochrons and morphological patterns within individual ridge segments. These features form angles of ∼10°–40° with the isochrons and are inferred to result from rift propagation at rates several times the spreading rate, representing the fastest propagators yet observed at a slow-spreading ridge. These fast propagators appear to have formed as a result of tectonic extension migrating along ridge segments as the segments change from more magmatic to less magmatic periods of spreading.

M. Tivey | M. C. Kleinrock | Jian Lin | B. Tucholke

[1] M. Cormier,et al. East Pacific Rise 18°–19°S: Asymmetric spreading and ridge reorientation by ultrafast migration of axial discontinuities , 1994 .

[2] W. Roest,et al. Fracture zones in the North Atlantic from combined Geosat and Seasat data , 1992 .

[3] Deborah K. Smith,et al. The role of seamount volcanism in crustal construction at the Mid‐Atlantic Ridge (24°–30°N) , 1992 .

[4] S. Carbotte,et al. Spreading rates, rift propagation, and fracture zone offset histories during the past 5 my on the Mid-Atlantic Ridge; 25°–27°30′ S and 31°–34°30′ S , 1991 .

[5] J. Sempere,et al. Evidence from gravity data for focused magmatic accretion along the Mid-Atlantic Ridge , 1990, Nature.

[6] H. Schouten,et al. Migration of mid-ocean-ridge volcanic segments , 1987, Nature.

[7] E. Parmentier,et al. Causes and rate-limiting mechanisms of ridge propagation: A fracture mechanics model , 1985 .