The boundary zone between continent and ocean, extending from the shoreline to the deep abyssal plain, spanning the continental shelf, continental slope and continental rise, and corresponding with an apparently sharp transition from continental crust to oceanic crust. In terms of tectonics setting, geomorphology and economic interest, there are profound differences between passive continental margins, which lie within plates, and active continental margins, which correspond to destructive plate margins.
Continental margins are major sites for the accumulation of sedimentary deposits, and in many places up to 15 km thickness has built up over the past 200 million years. Most of this is land-derived, and is transported onto and across the continental shelves by ocean currents and associated waves, storms and tides. Continental margins may be cut by submarine canyons, which act as major conduits of sediment transport. deposition on the continental margin in general, and the shelf in particular, is very sensitive to sea-level change, ocean chemistry, climate and tectonic modification of the hinterland: hence continental margin deposits are of great scientific interest because of their potential to preserve such information. Many depositional and erosional features of today’s continental margins formed under low sea-level conditions during glacial maxima in the pleistocene, when large parts of
the shelf were exposed; they are palimpsest features. The importance of the continental margins for petroleum exploration is such that abundant data are now available, particularly in the form of seismic stratigraphy and borehole records.
[See also hypsometry, ocean basin, plate tectonics]
- Burk, CA; Drake, CL (eds) (1974) The geology of continental margins. New York: Springer-Verlag.
- Global tectonics. Chichester: Wiley. ; ; (2009)
- Sedimentology and sedimentary basins: From turbulence to tectonics, 2nd edition. Chichester: Wiley-Blackwell. (2011)
- Sedimentology and stratigraphy. Oxford: Blackwell Science. (2009)
- Nittrouer, CA; Austin, JA; Field, ME et al. (eds) (2007) Continental margin sedimentation: From sediment transport to sequence stratigraphy (International Association of Sedimentologists Special Publication No. 37). Malden, MA: Blackwell.
- Stoker, MS; Evans, D; Cramp, A (eds) (1998) Geological processes on continental margins: Sedimentation, mass-wasting and stability. Bath: Geological Society.
CONTINENTS ARE THE large dry landmasses of the earth. They are areas of continental crust atop subterranean areas of the lithosphere. The...
A continental margin characterised by a wide continental shelf, separated by a continental slope and continental rise from the deep-ocean abyssal pla
The area of shallow sea floor (less than 200 m depth) adjacent to the continents, underlain by continental crust and effectively a submerged extensio