Lateglacial to Holocene relative sea-level changes in the Bjarkarlundur area near Reykholar, North West Iceland.

Lloyd, J.M.; Norddahl, H.; Bentley, M.J.; Newton, A.; Tucker, O.; Zong, Y.

Abstract

This paper presents results from seven isolation basins to investigate the relative sea-level history from the Lateglacial and the mid to late Holocene from the Bjarkarlundur area near Reykhólar on the Reykjanes peninsula in Northwest Iceland. Results presented help to constrain the timing and rate of RSL change since deglaciation and also the timing of deglaciation itself in the Bjarkarlundur area. The marine limit is estimated to be approximately 80 m above sea level based on an isolation basin with sill altitude at 79.1 m. The maximum age of this marine limit and, hence, local de¬glaciation is estimated at 12.2 14C ka BP. Relative sea level then fell rapidly during the late Bölling – early Alleröd at a rate of about 36 mm/14C year to below 50 m by 11.4 14C ka BP. After this the rate of RSL fall decreased significantly during the late Alleröd and Younger Dryas Chronozones (averaging 6 mm/14C year between 11.4 and 9.7 14C ka BP). Based on isolation basins with sill altitudes of 51.1 and 41.1 m our data constrains any possible fluctuation in relative sea level produced by re-growth of ice during the Younger Dryas to below 10 m. After 9.7 14C ka BP the rate of RSL fall increased significantly to about 26 mm/14C year to at least 9.014C ka BP. If eustatic sea level rise is taken into account and the calibrated timescale is used actual crustal uplift rates are estimated at +61 and +49 mm/cal. year during Lateglacial and early Holocene times respectively. During the mid to late Holocene relative sea-level then rose to at least 1 m above present day levels gradually falling to the present day level from 3.1 14C ka BP. These results demonstrate the potential of isolation basin data for investigating the timing and rate of relative sea-level change in Iceland. This can add important well constrained information on RSL when combined with data from raised beaches.

Citation

Lloyd, J., Norddahl, H., Bentley, M., Newton, A., Tucker, O., & Zong, Y. (2009). Lateglacial to Holocene relative sea-level changes in the Bjarkarlundur area near Reykholar, North West Iceland. Journal of Quaternary Science, 24, 816-831. https://doi.org/10.1002/jqs.1272

• Journal Article Type: Article
• Publication Date: 2009
• Journal: Journal of Quaternary Science
• Print ISSN: 0267-8179
• Electronic ISSN: 1099-1417
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 24
• Pages: 816-831
• DOI: https://doi.org/10.1002/jqs.1272
• Public URL: https://durham-repository.worktribe.com/output/1525066