Geological setting of gravel occurrences on the Belgian part of the North Sea
Deleu, S.; Van Lancker, V.R.M. (2007). Geological setting of gravel occurrences on the Belgian part of the North Sea, in: Van Lancker, V. et al. Management, research and budgetting of aggregates in shelf seas related to end-users (Marebasse). pp. 101-115 In: Van Lancker, V. et al. (2007). Management, research and budgetting of aggregates in shelf seas related to end-users (Marebasse). Belgian Science Policy: Brussel. 139 pp., more |
| Abstract | According to D’Olier (1981), the Flandrian sea-level rise caused a transgression over an initial surface topography whereby the present sandbank positions and shapes reflect ancient transitory islands, coalesced beaches, confluent channel bars and changing coastline positions. It is known that in this region of the North Sea, most of the underlying Palaeogene units consist of clayey sediments, alternated with only a few sandy layers. On top of these are, apart from scour hollow infillings with Pleistocene sediments, the sandbanks, which consist of Holocene sediments. A thin gravel lag veneer would form the lower part of the Holocene sediments followed by a sandy succession. Kirby and Oele (1975) found out that in the nearby Sandettié - Fairy Bank area, there is a well-developed graded succession from flint and shell gravel at the base up to shelly quartz sands. This succession indicates a decrease in energy conditions at the bed during the period of deposition and a subsequent slow regional rise in sea-level. Most probably the succession is a drape over an originally irregular seabed. Moreover, the Holocene thickness is less than 2.5m in the swales between the sandbanks, indicating possible source areas where gravel can be found. |
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