Abstract
The environmental dynamics at barrier-island salt marshes are reflected in lateral and vertical textural
patterns of the marsh sediment. During normal conditions, fine-grained sediment is deposited, whereas
during high-energy conditions also sand accretion can occur. This paper describes the occurrence and
importance of sand deposits for the building of salt marshes. The study was carried out in the Wadden Sea on
the islands of Schiermonnikoog (NL), Terschelling (NL) and the peninsula of Skallingen (DK). Firstly, we
recorded the presence of sand in the sediment representing initial salt-marsh formation. The results indicate
that part of the salt marsh developed under conditions that were dynamically enough for sand to be
transported. The spatial distribution of these conditions depends on soil elevation and location on the marsh,
modified by the presence of artificial sand dikes. Further we recorded the presence and thickness of sand
layers within the salt-marsh sediment. Sand layers are found on twenty percent of the marsh area and are
partly associated with the local sources of the sand, i.e. marsh creeks, the salt-marsh edge and washovers. In
total, sand layers contribute less than ten percent to the volume of marsh deposits on Schiermonnikoog. We
dated the layers using the thickness of the deposits and known marsh age. The ages of the layers indicate that
for the decadal occurrence of storms capable of depositing sand in the salt marsh, the local hydrodynamics
and availability of sand determine whether a site receives sand or not.
© 2011
Original language | English |
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Pages (from-to) | 240-254 |
Journal | Marine Geology |
Volume | 282 |
Issue number | 3-4 |
DOIs | |
Publication status | Published - 2011 |
Keywords
- sea-level rise
- southern north-sea
- danish wadden sea
- tidal marsh
- storm deposits
- vegetation
- succession
- england
- morphodynamics
- sedimentation