The middle and late Holocene Barrier Spit System at Vejers, Denmark: Structure and Development

Abstract

Georadar data (72 km) combined with borings and datings form the basis of a study of the three-dimensional build-up of the middle and late Holocene barrier spit system at Vejers, Denmark. The georadar data reveal one barrier spit covering 15-20 km2 , with an average thickness of approximately 10 meters. This barrier spit shows a tripartite build-up. At the base a shoal sand unit of well-sorted, fine- to medium-grained sand occurs. The overlying interval constitutes a barrier core unit, stretching from north to south, and composed of alternating layers of westward dipping coarse sand- and gravel layers. At the top of these layers aeolian sand sheet and dune deposits occur. The barrier core unit is followed to the east by a back-barrier unit of fine- to medium-grained sand, with a varying content of silt and plant fragments. These deposits are also overlain by aeolian sediments. A second, smaller and more inland situated barrier spit occurs in the central and southern parts of the investigated area. It appears that barrier spit formation took place in three main stages. The initial stage occurred between c. 6500 and c. 4000 B.P. (transgressive period). Barrier spit consolidation and rapid growth took place between c. 4000 B.P. and c. 1200 A.D. (early highstand period). Final development and large-scale dune formation took place after 1200 A.D. (highstand period). The dominance of west-ward dipping strata in the spit deposits indicates consistent seaward progradation of the spit. The shape of the spit indicates southward growth. Apparently the spit formed under the influence of a strong southward directed littoral drift, but the overall alignment of the spit was controlled by swash processes.

Sediments and morphodynamics along the Danish West Coast from Skagen to the Wadden Sea

“…The presence of Horns Rev has led to the construction of the marine foreland north/east of Blåvands Huk. This foreland consists of a system of sandy/gravelly spits which are attached to the Saalian moraine landscape north of the lake Fil Sø (Nielsen et al, 1995;Clemmensen et al, 1996). The spit growth was initiated about 7000 years ago when the rising sea the level started to erode the former glacial deposits and the spit system prograded south and west.…”