GEOSCAN, résultats de la recherche


TitreRapid tidal expansion in the upper Bay of Fundy, Canada: Validation of the Glooscap legend
AuteurShaw, J; Amos, C L; Greenberg, D A; O'Reilly, C T; Parrott, D R; Patton, E
SourceAtlantic Geology vol. 46, 2010 p. 67
Séries alt.Secteur des sciences de la Terre, Contribution externe 20100044
RéunionAGS Colloquim 2010; Wolfville, NS; CA; février 5-6, 2010
Documentpublication en série
Mediapapier; en ligne; numérique
ProvinceRégion extracotière de l'est
Lat/Long OENS -67.5000 -64.5000 45.5000 44.2500
Sujetsdistribution des sédiments; transport des sediments; sédiments marins; stabilité du sédiment; marées; dépôts de marée; milieux de marée; géologie marine; sédimentologie
ProgrammeÉnergie renouvelable offshore, Géoscience en mer
Résumé(disponible en anglais seulement)
Tidal models for the Bay of Fundy, Canada - site of the highest recorded modern tide - show that tidal amplification began in the early Holocene, and that by c. 5000 14C yr BP range was almost 80 % of the present range. Empirical data consisting of 146 sea-level index points and other observations appear to contradict model results. Aggregated relative sea-level data for Chignecto Bay and Minas Basin show that rapid tidal expansion began c. 3400 14C yr BP. However, if we separate these two geographically separate data sets, evidence for this rapid late-Holocene tidal expansion is confined to Minas Basin. We explain this singularity by positing a barrier across Minas Basin that delayed tidal expansion. With the rapid breakdown of this barrier and near-instantaneous tidal expansion, water temperature dropped, tidal currents and turbidity increased, and the form of the inner estuary was changed from lagoonal/mesotidal to macrotidal. We argue that the catastrophic breakdown of the barrier is related in the aboriginal legend of Glooscap, showing that aboriginal peoples observed the rapid environmental changes and preserved an oral record for 3400 years.