2006 Strategic Environmental Assessment SEA7 Technical Report - hydrocarbon prospectivity, earthquakes, continental shelves and Rockall Trough surficial and sea-bed geology and sea-bed processes
This report is a contribution to the Strategic Environmental Assessment (SEA7) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). Investigations of the hydrocarbon prospectivity and earthquake activity include the whole of SEA7 but in this report investigations of the sea-bed sediments are restricted to the Hebrides Shelf, Rockall Trough and east Rockall Bank.
On the Hebrides Shelf, Hebrides Slope, east Rockall Bank and in the deep-water Rockall Trough the modern sea-bed sediments are mainly composed of mixtures of former glacial deposits and grains of modern interglacial biogenic carbonate shell. Former glacial deposits and modern biogenic carbonate are now mainly mixed and transported by wave-orbital currents and residual currents on Rockall Bank and by combinations of wave-orbital currents, tidal currents and residual currents on the Hebrides Shelf and upper Hebrides Slope. Below approximately 300 metres water depth in the Rockall Trough the sea-bed sediments are mainly transported by circulating deep-water residual currents.
On the Hebrides Shelf, Hebrides Slope, east Rockall Bank and in the deep-water Rockall Trough the modern sea-bed sediments are mainly composed of mixtures of former glacial deposits and grains of modern interglacial biogenic carbonate shell. Former glacial deposits and modern biogenic carbonate are now mainly mixed and transported by wave-orbital currents and residual currents on Rockall Bank and by combinations of wave-orbital currents, tidal currents and residual currents on the Hebrides Shelf and upper Hebrides Slope. Below approximately 300 metres water depth in the Rockall Trough the sea-bed sediments are mainly transported by circulating deep-water residual currents.
dataset
Strategic Environmental Assessment (SEA) data portal
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British Geological Survey
:
BGS_SEA_107
English
Environment
Geoscientific information
Oceans
Geoscientific information
Oceans
SeaDataNet Parameter Discovery Vocabulary:
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SeaVoX Vertical Co-ordinate Coverages:
Geology
Free:
-24.00,
55.20,
-5.00,
60.20
publication: 2006-01-01
2006-01-01
-
2006-01-01
British Geological Survey (BGS)
Paul Henni
Murchison House, West Mains Road,
Edinburgh,
EH9 3LA,
UK
tel: +44 (0)131 667 1000
email:
offshoredata@bgs.ac.uk
Role: custodian
Department for Energy and Climate Change (DECC)
Admiralty Way,
London,
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UK
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Data Quality
This report was prepared by Richard Holmes, Ken Hitchen and Lars Ottemoller of the British Geological Survey as part of the UK Department of Energy and Climate Change's Offshore Energy Strategic Environmental Assessment programme. Sediment analyses have been derived from samples taken from sea-bed to approximately 10 cm below sea-bed. After laboratory quantitative analysis of dried sediments, the BGS classifies sea-bed sediment textures to accord with modified Folk (1954) classes, which are based on weight % of sediment grains over a range of Wentworth size classes. The values of weight % carbonate in the total sediment and in the sediment-size classes are also routinely determined. These values can be interpreted as a measure of the inputs to the sediment from biological sources of calcium carbonate. For the BGS regional surveys, the proportions of mud, sand and gravel were quantified by square-mesh wet sieving using a 63micron sieve to determine mud (a mixture of silt and clay) and with a 2mm sieve to determine gravel (in the granular gravel to pebble and larger size classes).
Minimal Distance:
5 http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_19139_Schemas/resources/uom/gmxUom.xml#m
Constraints
Metadata about metadata
aba64100-c15f-4de3-e044-0003ba6f30bd
British Geological Survey (BGS)
Mary Mowat
tel: +44 (0)131 667 1000
email:
offshoredata@bgs.ac.uk
Role: point of contact
2011-08-30