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THE MODELLING AND DYNAMICS OF THE QUATERNARY GEOLOGY OF THE SOUTHERN NORTH SEA AND THEIR APPLICATION TO ENVIRONMENTAL PROTECTION AND INDUSTRIAL DEVELOPMENTS

Objective


The development of the southern North Sea basin during the Quaternary has been studied by geologists from 5 countries. 9 boreholes were drilled and a seismic survey carried out. Study of the Belgian borehole showed that the tertiary deposits belong to the Lower Eocene and were deposited in a shallow marine environment. They are covered by Quaternary sediments which fill a valley like depression scoured in tertiary deposits. The lower Quaternary sequence consists of probably reworked marine sounds, deposited by a fluvial or fluvio periglacial system during the Weichselian. The upper Quaternary sequence has a Holocene age and consists of the active seabed sediments.

Several generations of valley erosion have been identified and mapped in the western Danish sector. The ages of the valley systems have been determined by analysis of foraminiferal assemblages obtained form boreholes. The late Quaternary deep erosional channel systems in the German secotr have been mapped and the clay mineralogy of Cretaceous, Tertiary and Quaternary sediments has been studied.

Sets of contour maps illustrating depths to 26 seismic sequence boundaries and isopachs for each of the 26 late Ceuozoic seismic sequences have been completed. A study has been done of the lateral changes in facies of successive seismic sequences along the transect and information gained on lithology of the late Cenozoic sediments. The morphology of buried glacial valleys in the southern North Sea and the nature of their fill is also under study. A digitally recorded and processed multichannel seismic profile between Cromer and Sylt has provided the first continuous section through the Miocene to middle Pleistocene delta complex of the southern North Sea basin.
A series of boreholes will be drilled to explore the Quaternary history of the southern North Sea Basin. This forms part of a joint European Geological Surveys programme to investigate the dynamic development of the basin and will contribute to environment models which turn will aid the development of an acceptable exploitation strategy for the area. The boreholes will be sited to assist basin-wide correlation and to identify the development of the deltas of the major European rivers in early Pleistocene times. The results will also provide data on climate and sea-level changes and from the younger sediments, temporal changes in pollution.

Coordinator

NERC British Geological Survey
Address
Station Edinburgh 19 Grange Terrace
EH9 2LF Edinburgh
United Kingdom

Participants (4)

Danmarks Geologiske Undersøgelse
Denmark
Address

2400 København Nv
GEOLOGICAL SURVEY OF BELGIUM
Belgium
Address
13,Jennerstraat 13
1040 Bruxelles
Niedersächsisches Landesamt für Bodenforschung
Germany
Address

30161 Hannover
Rijks Geologische Dienst - Nederland
Netherlands
Address

2000 AD Haarlem