TY - JOUR

T1 - Optical dating of dune ridges on Rømø

T2 - a Barrier Island in the Wadden Sea, Denmark

AU - Madsen, Anni Tindahl

AU - Murray, A. S.

AU - Andersen, Thorbjørn Joest

PY - 2007

Y1 - 2007

N2 - The application of optically stimulated luminescence (OSL) to the dating of recent aeolian sand ridges on Rømø, an island off the southwest coast of Denmark, is tested. These sand ridges began to form approximately 300 years ago, and estimates of the ages are available from historical records. Samples for OSL dating were taken ~0.5 m below the crests of four different dune ridges; at least five samples were recovered from each ridge to test the internal consistency of the ages. Additional samples were recovered from the low lying areas in the swales and from the scattered dune formations in a broad hummocky area landward of the well-defined ridges. Despite low luminescence signals, we were able to obtain a mean age for the youngest ridge of 17±2 years, consistent with the known age of ~28 years. Optical ages of individual samples in our study ranged between 10±3 years and 690±50 years, and all ages were broadly consistent with those expected from historical information. The oldest aeolian surface on Rømø appears to be 370±30 years. This is built on what we interpret as a marine sandbank, whose surface is ~700 years old. The sand ridges seaward of the hummocky dune field have well-defined building phases separated by inactive periods and the first major ridge formed ~235 years ago. This study demonstrates that optical dating can be successfully applied to these young aeolian sand deposits, and we conclude that OSL dating is a powerful chronological tool in studies of coastal change.

AB - The application of optically stimulated luminescence (OSL) to the dating of recent aeolian sand ridges on Rømø, an island off the southwest coast of Denmark, is tested. These sand ridges began to form approximately 300 years ago, and estimates of the ages are available from historical records. Samples for OSL dating were taken ~0.5 m below the crests of four different dune ridges; at least five samples were recovered from each ridge to test the internal consistency of the ages. Additional samples were recovered from the low lying areas in the swales and from the scattered dune formations in a broad hummocky area landward of the well-defined ridges. Despite low luminescence signals, we were able to obtain a mean age for the youngest ridge of 17±2 years, consistent with the known age of ~28 years. Optical ages of individual samples in our study ranged between 10±3 years and 690±50 years, and all ages were broadly consistent with those expected from historical information. The oldest aeolian surface on Rømø appears to be 370±30 years. This is built on what we interpret as a marine sandbank, whose surface is ~700 years old. The sand ridges seaward of the hummocky dune field have well-defined building phases separated by inactive periods and the first major ridge formed ~235 years ago. This study demonstrates that optical dating can be successfully applied to these young aeolian sand deposits, and we conclude that OSL dating is a powerful chronological tool in studies of coastal change.

KW - Faculty of Science

KW - kronologier

KW - Chronologies

KW - aeolian sediments

KW - OSL

KW - optically stimulated luminescence

U2 - DOI:10.2112/05-0471.1

DO - DOI:10.2112/05-0471.1

M3 - Journal article

VL - 23

SP - 1259

EP - 1269

JO - Journal of Coastal Research

JF - Journal of Coastal Research

SN - 0749-0208

IS - 5

ER -