Accretion and Water-Levels in Enclosed, Seepage Lagoons: Examples from Nova Scotia
Keywords:Sea-level, pollen, salt marsh, gravel barriers
Lithostratigraphic and biostratigraphic examination of lagoonal sequences in close proximity to an enclosing gravel ridge, has shown a linkage between lagoon accretionary characteristics and the developmental domain (growth, consolidation, breakdown and reformation) of the gravel barrier. Seepage lagoon water-level rise has occurred on instantaneous time-scales following barrier inlet closure, whereas lagoon accretion has developed over time-scales of 101 - 102 years. Despite this lag, lagoon stratigraphies have accreted more rapidly than relative sea-level (RSL) rise. Switching of lagoons between enclosed seepage and tidal states, as a result of barrier dynamics, has an important control on lagoon accretion, and further renders the use of the resultant stratigraphies for sea-level interpretation difficult.