Slab window

Diagram of a cross-section of the Patagonia slab window. The Nazca Plate and Antarctic Plate are colliding with the South American Plate at the Chile Ridge.[1]

In geology, a slab window is a gap that forms in a subducted oceanic plate when a mid-ocean ridge meets with a subduction zone and plate divergence at the ridge and convergence at the subduction zone continue, causing the ridge to be subducted.[2] Formation of a slab window produces an area where the crust of the over-riding plate is lacking a rigid lithospheric mantle component and thus is exposed to hot asthenospheric mantle (for a diagram of this, see the link below). This produces anomalous thermal, chemical and physical effects in the mantle that can dramatically change the over-riding plate by interrupting the established tectonic and magmatic regimes.[2] In general, the data used to identify possible slab windows comes from seismic tomography and heat flow studies.[3]

  1. ^ Russo, R.M.; VanDecar, John C.; Comte, Diana; Mocanu, Victor I.; Gallego, Alejandro; Murdie, Ruth E. (2010). "Subduction of the Chile Ridge: Upper mantle structure and flow". GSA Today: 4–10. doi:10.1130/gsatg61a.1. ISSN 1052-5173.
  2. ^ a b Thorkelson, Derek J., 1996, Subduction of diverging plates and the principles of slab window formation, Tectonophysics, v. 255, p. 47-63
  3. ^ van Wijk, J.W., Govers, R., Furlong, K.P., 2001, Three-dimensional thermal modeling of the California upper mantle: a slab window vs. stalled slab, Earth and Planetary Letters, v. 186, p. 175-186