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TitleThe Var submarine sedimentary system: understanding Holocene sediment delivery processes and their importance to the geological record
AuthorMulder, T; Savoye, B; Piper, D J W; Syvitski, J P M
SourceGeological Processes on Continental Margins: Sedimentation, Mass-Wasting and Stability; by Stoker, M S (ed.); Evans, D (ed.); Cramp, A (ed.); Special Publication of the Geological Society of London no. 129, 1998 p. 145-166,
Alt SeriesGeological Survey of Canada, Contribution Series 1996417
PublisherGeological Society of London
Mediapaper; on-line; digital
File formatpdf
Lat/Long WENS 7.0000 8.5000 50.0000 43.0000
Subjectssedimentology; hydrogeology; Pliocene; deltas; deltaic deposits; submarine fans; sediment transfer; turbidity currents; sedimentary environments; mass wasting; hydrologic environment; sedimentation rates; Var Canyon; hyperpycnal events; earthquake hazard; Quaternary
Illustrationshistograms; graphs; cross-sections
Released1998 01 01
AbstractThe Var system extends off Nice in the Western Mediterranean. It comprises a river, a delta and a submarine valley leading to a deep-sea fan that together have been in operation since the Early Pliocene. The Var system is an area experiencing active sediment transport, where at least three major types of sediment transfer process are identified: hyperpycnal turbid plumes, surge-like turbidity currents generated by shallow failures induced by excess pore pressure during river flood periods, and by large earthquake-triggered slides. The last two processes might generate higher-density turbidity currents, but at different return intervals. Hydrological data, direct observations of the sea floor, geotechnical testing and numerical modelling confirm the very high frequency of these sediment transfer events. Some of the processes have catastrophic surge behaviour, others are continuous during periods of river flooding. In the latter case, all the sediment supplied to the vicinity of the river mouth is transferred seaward without or with only brief periods of deposition. The geological record of such continuous activity remains difficult to identify. The palaeo-events identified in sedimentary series are often widespread, high-magnitude events with return periods close to a millennium, i.e. usually beyond historical records. Normal 'background' processes provide only thin deposits that are not interpretable in the geological record.