1. Late Holocene sea-level changes and isostasy in western Denmark
- Author
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Gehrels, W. Roland, Szkornik, Katie, Bartholdy, Jesper, Kirby, Jason R., Bradley, Sarah L., Marshall, William A., Heinemeier, Jan, and Pedersen, Jørn B.T.
- Subjects
ABSOLUTE sea level change ,GLACIAL isostasy ,MARSHES - Abstract
Abstract: Cores and exposed cliff sections in salt marshes around Ho Bugt, a tidal embayment in the northernmost part of the Danish Wadden Sea, were subjected to
14 C dating and litho- and biostratigraphical analyses to reconstruct paleoenvironmental changes and to establish a late Holocene relative sea-level history. Four stages in the late Holocene development of Ho Bugt can be identified: (1) groundwater-table rise and growth of basal peat (from at least 2300 BC to AD 0); (2) salt-marsh formation (0 to AD 250); (3) a freshening phase (AD 250 to AD 1600?), culminating in the drying out of the marshes and producing a distinct black horizon followed by an aeolian phase with sand deposition; and (4) renewed salt-marsh deposition (AD 1600? to present). From 16 calibrated AMS radiocarbon ages on fossil plant fragments and 4 calibrated conventional radiocarbon ages on peat, we reconstructed a local relative sea-level history that shows a steady sea-level rise of 4 m since 4000 cal yr BP. Contrary to suggestions made in the literature, the relative sea-level record of Ho Bugt does not contain a late Holocene highstand. Relative sea-level changes at Ho Bugt are controlled by glacio-isostatic subsidence and can be duplicated by a glacial isostatic adjustment model in which no water is added to the world''s oceans after ca. 5000 cal yr BP. [Copyright &y& Elsevier]- Published
- 2006
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