Search results
Results From The WOW.Com Content Network
A model of the subducting Farallon slab under North America. In geology, the slab is a significant constituent of subduction zones. [1] Subduction slabs drive plate tectonics by pulling along the lithosphere to which they attach in a process known as slab pull and by inducing currents in the mantle via slab suction. [2]
The subduction of bathymetric highs such as aseismic ridges, oceanic plateaus, and seamounts has been posited as the primary driver of flat slab subduction. [3] The Andean flat slab subduction zones, the Peruvian slab and the Pampean (Chilean) flat slab, are spatially correlated with the subduction of bathymetric highs, the Nazca Ridge and the Juan Fernandéz Ridge, respectively.
A Wadati–Benioff zone (also Benioff–Wadati zone or Benioff zone or Benioff seismic zone) is a planar zone of seismicity corresponding with the down-going slab in a subduction zone. [1] Differential motion along the zone produces numerous earthquakes , the foci of which may be as deep as about 670 km (420 mi).
retreating subduction: caused by weak coupling between the lower and upper plate which leads to the opening of a back arc basin and the subduction zone being moved by slab rollback. stable subduction: caused by intermediate coupling between the lower and upper plate. The subduction zone generally stays in the same place and the subduction plate ...
The flat slab subduction associated with the Nazca Ridge has been linked to the cessation of volcanism in the Andes Mountains at about 4 Ma. [6] The subduction has also been linked with the formation of the Fitzcarrald Arch, which is a 400,000 km 2 (150,000 sq mi), 400 to 600 m (1,300 to 2,000 ft) high, domed topographic feature that defines ...
The flat-slab has caused an uplift of Sierras Pampeanas which begun first in the north and then moved southwards over millions of years. [2] The oldest noted uplift episode associated with Pampean flat-slab is that of Sierra de Aconquija (27 °S) from 7.6 to 6 million years ago (Ma) in the Late Miocene epoch. [2]
Slab suction is weaker than slab pull, which is the strongest of the driving forces. When measuring the forces of these two mechanisms, slab pull in subducting plate boundaries for upper mantle slabs is 1.9 × 10^21 N. [ clarification needed ] In comparison slab suction in the upper and lower mantle totaled 1.6 × 10^21 N. [ 3 ]
In plate tectonics, slab detachment or slab break-off may occur during continent-continent or arc-continent collisions. When the continental margin of the subducting plate reaches the oceanic trench of the subduction zone , the more buoyant continental crust will in normal circumstances experience only a limited amount of subduction into the ...