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TitleMorphosedimentary development of drumlin-flank barriers with rapidly rising sea level, Story Head, Nova Scotia
AuthorCarter, R W G; Orford, J D; Forbes, D L; Taylor, R B
SourceSedimentary Geology vol 69, 1990 p. 117-138, https://doi.org/10.1016/0037-0738(90)90104-2
Year1990
Alt SeriesGeological Survey of Canada, Contribution Series 26290
PublisherElsevier BV
Documentserial
Lang.English
Mediapaper; on-line; digital
File formatpdf
ProvinceNova Scotia
NTS11D/10; 11D/11; 11D/12; 11D/14; 11D/15; 11D/16; 11F/09; 11F/10; 11F/16; 11G/13
AreaStory Head
Lat/Long WENS -64.0000 -61.0000 45.2500 44.7500
Lat/Long WENS -61.0000 -60.0000 46.0000 45.5000
Subjectssurficial geology/geomorphology; marine geology; drumlins; longshore bars; sea level changes; sea level fluctuations; shore features; shoreline changes; shorelines; gravel bars; sediments; coastal erosion; coastal studies; Quaternary
Illustrationssketch maps; photographs; tables
AbstractThe morphodynamic and morphosedimentary development of drift-aligned and swash-aligned coarse clastic barriers plays an important role in the evolution of paraglacial coasts. This paper discusses the development of two contrasting barriers attached to a drumlin headland at Story Head on the Atlantic coast of Nova Scotia, southeastern Canada. A 3-4 mm a?1 sea-level rise is forcing rapid barrier changes, including landward migration (rollover) of the swash-aligned barrier at 5-8 m a?1, and barrier thinning, elongation and breaching. Morphological development reflects the highly variable longshore distribution of wave power, imposed initially by the topography of the drumlin and its position in the incident wave field, and later by morphosedimentary feedback resulting from such gradients. Gradual reduction of an inherently intermittent sediment supply leads to reworking (cannibalization) of the barrier, ultimately finding expression in a series of distinct wave-formed sediment cells. Further diminution of the sediment supply, coupled to cell development, results in the drift-aligned system decaying into a series of high-water residuals, separated by breach depressions, with splayed spit recurves at the margins. Although the swash-aligned barrier is stretched within the predominant overwash regime and may eventually separate from the headland, it has remained intact until very recently, when an initial breach occurred. The evolutionary sequence of the headland-barrier system has an important effect on adjacent sedimentary environments.
GEOSCAN ID203808