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TitleOrganisational controls, typologies and time scales of paraglacial gravel-dominated coastal systems
AuthorOrford, J D; Forbes, D L; Jennings, S C
Source29th Binghamton geomorphology symposium: coastal geomorphology; by Gares, P A (ed.); Sherman, D J (ed.); Geomorphology vol. 48, issue 1-3, 2002 p. 51-85,
LinksAbstract - Résumé
Alt SeriesGeological Survey of Canada, Contribution Series 1999122
PublisherElsevier BV
Meeting29th Binghamton geomorphology symposium: coastal geomorphology; Woods Hole, MA; US; November 13-15, 1998
Mediapaper; on-line; digital
File formatpdf
Subjectssedimentology; gravels; sediments; storm deposits; sea level changes; sea level fluctuations; sediment transport; sediment distribution; sedimentation; sedimentation rates; shoreface deposits
Illustrationscross-sections, stratigraphic; tables; photographs; location maps; graphs; formulae
AbstractThe fundamental controls on the initiation and development of gravel-dominated deposits (beaches and barriers) on paraglacial coasts are particle size and shape, sediment supply, storm wave activity (primarily runup), relative sea-level (RSL) change, and terrestrial basement structure (primarily as it affects accommodation space). This paper examines the stochastic basis for barrier organisation as shown by variation in gravel barrier architecture. We recognise punctuated self-organisation of barrier development that is disrupted by short phases of barrier instability. The latter results from positive feedback causing barrier breakdown when sediment supply is exhausted. We examine published typologies for gravel barriers and advocate a consolidated perspective using rate of RSL change and sediment supply. We also consider the temporal variation in controls on barrier development. These are examined in terms of a simple behavioural model (BARCH) for prograding gravel barrier architecture and its sensitivity to such controls. The nature of macroscale (102-103 years) gravel barrier development, including inherited characteristics that influence barrier genesis, as well as forcing from changing RSL, sediment supply, headland control and barrier inertia, is examined in the context of long-surviving barriers along the southern England coastline.