|
|||||
|
|
Late Holocene sea-level changes and isostasy in western Denmark |
|
| Authors: | W Roland Gehrels Katie Szkornik Jason R Kirby William A Marshall Jørn BT Pedersen |
| Institution: | a School of Geography, University of Plymouth, Plymouth, PL4 8AA, UK b Institute of Geography, University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen K, Denmark c School of Biological and Earth Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK d Department of Earth Sciences, University of Durham, Durham, DH1 3LE, UK e AMS 14C Dating Centre, Department of Physics and Astronomy, University of Århus, DK-8000 Århus C, Denmark |
| 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 14C 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. |
| Keywords: | Diatoms Foraminifera Glacio-isostasy Ho Bugt North Sea Wadden Sea Salt marsh |
| 本文献已被 ScienceDirect 等数据库收录！ | |