From 1 - 10 / 61
  • Categories  

    The British Geological Survey hold a collection of data recorded during marine geophysical surveys which includes digital data and analogue records. These data result from approximately 350,000 line kilometres of multi-instrument geophysical survey lines. The data include seismic, sonar, magnetic, gravity, echo sounder, multibeam bathymetry and navigation data. The seismic data are mainly for airgun, sparker, boomer and pinger. The data were primarily collected by BGS and the collection also includes additional third party data. The data are primarily from the UKCS (United Kingdom Continental Shelf). The data are stored within the National Geoscience Data Centre (NGDC) and the Marine Environmental Data and Information Network (MEDIN) Data Archive Centre (DAC) for Geology and Geophysics. The majority of legacy geophysical paper records are available as scanned images viewable via the BGS Offshore GeoIndex www.bgs.ac.uk/GeoIndex/offshore.htm. Other records can be scanned on request. Older records are of variable quality. Data not yet available online including segy are available on request enquiries@bgs.ac.uk. The data are applicable to a wide range of uses including environmental, geotechnical, geophysical and geological studies. Reference: Fannin, NGT. (1989) Offshore Investigations 1966-87. British Geological Survey Technical Report WB/89/2, British Geological Survey.

  • Categories  

    The British Geological Survey has collected over 50000 offshore samples using grabs, dredges and shallow coring devices (to a maximum depth of 6m below the sea bed). The collection also includes additional third party data and has assisted in the creation of BGS Marine Geology Maps. The distribution is variable, but in general there are sample stations spaced about every 5 - 10km across the entire UK Continental Shelf (UKCS). In some localised areas the sampling density is much higher. The data held includes digital data and analogue records (sample data sheets), plus associated physical sample material. Sample data sheets which have been scanned contain index information and geological descriptions and are more detailed from 1983 onwards. Coded geological descriptions were entered on sheets which were subsequently digitised, and this information is available for about 10,000 samples. The data also includes results of analyses such as micropalaeontological examination or age dating. Particle Size Analysis, geochemistry and geotechnical data are described in separate metadata entries. Sample material are managed as part of the BGS Materials collection and are available for examination and subsampling. The data are stored within the National Geoscience Data Centre (NGDC) and Marine Environmental Data and Information Network (MEDIN) Data Archive Centre (DAC) for Geology and Geophysics. Data are delivered via the BGS Offshore GeoIndex www.bgs.ac.uk/GeoIndex/offshore.htm.The activity and scan layers contains location information, metadata and links to scanned sample datasheets/core logs, and the geological, geotechnical, geochemical and sea-bed sediment data layers contain observations and/or measurements as digital values. The data are applicable to a wide range of uses including environmental, geotechnical and geological studies. Reference: Fannin, NGT. (1989) Offshore Investigations 1966-87. British Geological Survey Technical Report WB/89/2, British Geological Survey.

  • Categories  

    The BGS Seabed Sediments 250k dataset is vector data is vector data which reflects the distribution of seabed substrate types of the UK and some of its adjacent waters at 1:250,000 scale. This comprehensive product provides a digital compilation of the paper maps published by BGS at the same scale, as well as, additional re-interpretations from regional geological studies. The seabed is commonly covered by sediments that form a veneer or thicker superficial layer of unconsolidated material above the bedrock. These sediments are classified based on their grain size reflecting the environment in which were deposited. This information is important to a range of stakeholders, including marine habitat mappers, marine spatial planners, offshore industries (in particular, the dredging and aggregate industries). This dataset was primarily based on seabed grab samples of the top 0.1 m, combined with cores, dredge samples and sidescan sonar acquired during mapping surveys since the early 1970s. The variations in data density will be reflected in the detail of the mapping.

  • Categories  

    Linear features (shown as polylines) represent seven classes of geological structural features e.g. faults, folds or landforms e.g. buried channels, glacial drainage channels at the ground or bedrock surface (beneath superficial deposits). The scale of the data is 1:10 000 scale. Onshore coverage is partial with approximately 30% of England, Scotland and Wales available in the version 2 data release. BGS intend to continue developing coverage at this scale; current focus is to include all large priority urban areas, along with road and rail transport corridors. Linear features are associated most closely with the bedrock theme either as an intrinsic part of it for example marine bands or affecting it in the case of faults. However landform elements are associated with both bedrock and superficial deposits. The linear features are organised into seven main categories: Alteration area indicating zones of change to the pre-existing rocks due to the application of heat and pressure can occur round structural features such as faults and dykes. Fault where a body of bedrock has been fractured and displaced by a large scale process affecting the earth's crust. Fold where strata are bent or deformed resulting from changes or movement of the earth's surface creating heat and pressure to reshape and transform the original horizontal strata. Folds appear on all scales, in all rock types and from a variety of causes. Fossil horizons where prolific fossil assemblages occur and can be used to help establishing the order in which deposits were laid down (stratigraphy). These horizons allow correlation where sediments of the same age look completely different due to variations in depositional environment. Mineral vein where concentrations of crystallised mineral occur within a rock, they are closely associated with faulting but may occur independently. Landforms define the landscape by its surface form; these include glacial features such as drumlins, eskers and ice margins. Rock identifies key (marker) beds, recognised as showing distinct physical characteristics or fossil content. Examples include coal seams, gypsum beds and marine bands. The data are available in vector format (containing the geometry of each feature linked to a database record describing their attributes) as ESRI shapefiles and are available under BGS data licence.

  • Categories  

    Data identifying landscape areas (shown as polygons) attributed with geological names and rock type descriptions. The scale of the data is 1:10 000 scale. Onshore coverage is partial with approximately 30% of England, Scotland and Wales available in the version 2 data release. BGS intend to continue developing coverage at this scale; current focus is to include all large priority urban areas, along with road and rail transport corridors. Superficial deposits are the youngest geological deposits formed during the most recent period of geological time, the Quaternary, which extends back about 2.58 million years from the present. They lie on top of older deposits or rocks referred to as bedrock. Superficial deposits were laid down by various natural processes such as action by ice, water, wind and weathering. As such, the deposits are denoted by their BGS lexicon name, which classifies them on the basis of mode of origin (lithogenesis) with names such as, 'glacial deposits', 'river terrace deposits' or 'blown sand'; or on the basis of their composition such as 'peat'. Most of these superficial deposits are unconsolidated sediments such as gravel, sand, silt and clay. The digital data includes attribution to identify each deposit type (in varying levels of detail) as described in the BGS Rock Classification Scheme (volume 4). The data are available in vector format (containing the geometry of each feature linked to a database record describing their attributes) as ESRI shapefiles and are available under BGS data licence.

  • Categories  

    Data identifying landscape areas (shown as polygons) attributed with geological names and rock type descriptions. The scale of the data is 1:10 000 scale providing bedrock geology. Onshore coverage is partial with approximately 30% of England, Scotland and Wales available in this version 2 data release. BGS intend to continue developing coverage at this scale; current focus is to include all large priority urban areas, along with road and rail transport corridors. Bedrock geology describes the main mass of solid rocks forming the earth's crust. Bedrock is present everywhere, whether exposed at surface in outcrops or concealed beneath superficial deposits or water bodies. The bedrock geology of Great Britain is very diverse and includes three broad classes based on their mode of origin: igneous, metamorphic and sedimentary. The data includes attribution to identify each rock type (in varying levels of detail) as described in the BGS Rock Classification Scheme (volumes 1-3). The bedrock has formed over long periods of geological time, from the Archean eon some 7500 million years ago, to the relatively young Pliocene, 58 million years ago. The age of the rocks is identified in the data through their BGS lexicon name (published for each deposit at the time of the original survey or subsequent digital data creation). For stratified rocks i.e. arranged in sequence, this will usually be of a lithostratigraphic type. Other rock types for example intrusive igneous bodies will be of a lithodemic type. More information on the formal naming of UK rocks is available in the BGS Lexicon of Named Rock Units. Geological names are based on the lithostratigraphic or lithodemic hierarchy. The lithostratigraphic scheme arranges rock bodies into units based on rock-type and geological time of formation. Where rock-types do not fit into the lithostratigraphic scheme, for example intrusive, deformed rocks subjected to heat and pressure resulting in new or changed rock types; then their classification is based on their rock-type or lithological composition. This assesses visible features such as texture, structure, mineralogy. The data are available in vector format (containing the geometry of each feature linked to a database record describing their attributes) as ESRI shapefiles and are available under BGS data licence.

  • Categories  

    The map shows the location of excess sample materials from the G-BASE (Geochemical Baseline Survey Of The Environment) geochemistry project:- stream sediments, panned heavy mineral concentrates and soils are stored long term in the National Geoscience Data Centre and are available for use in other projects. The Minerals Programme (incorporating the Mineral Reconnaissance Programme) sample collection contains reference samples of drill cores, rocks, tills, soils, stream sediments and panned concentrates. These samples were collected in the period 1974 - to date in mineralised and potentially mineralised areas of the United Kingdom, principally in the northern and western Britain.

  • Categories  

    The data set consists of the results of particle size analysis (PSA) performed on approximetaly 29,000 sea-bed sediment samples collected by BGS from the UK Continental Shelf and adjacent deep water areas, mostly using sediment grabs, but also sediment corers on occasions. Measurements were also made on approximately 8000 downhole sub-samples from shallow cores and boreholes. Data from other UK organisations have also been added to the PSA dataset. The data are stored as part of the National Geoscience Data Centre (NGDC) and the Marine Environmental Data and Information Network (MEDIN) Data Archive Centre (DAC) for Geology and Geophysics. Data are delivered via the BGS Offshore GeoIndex www.bgs.ac.uk/GeoIndex/offshore.htm Seabed Sediment Data layers.

  • Categories  

    The British Institutions Reflection Profiling Syndicate (BIRPS) shot approximately 12,000 km of deep, multi-channel seismic reflection data around the British Isles from 1981 to 1991 during 14 surveys. Recording depths vary depending on the purpose of the survey but range from 15 s to 40 s two-way time. Raw and processed digital data are archived by BGS who make the data available subject to the cost of reproduction and handling. Seismic sections and other analogue ancillary data are available for some surveys. Gravity and magnetic data may also be available.

  • Categories  

    This low-resolution image has been produced from BGS land and marine gravity data. The colour was generated using the BGS COLMAP software package. Colour levels are defined by histogram equalisation. Combining this image with the grey shaded relief image produces a similar image to the colour shaded relief image. The measured gravity values have been corrected in order to show the anomalies attributable to variations in crustal density. In broad terms the blues are attributable to large volumes of low density rocks, the reds to high density rocks. Significant lows occur, for instance, over areas of thick, low density sedimentary rocks(e.g. Cheshire Basin, Wessex Basin), or large granites (eg Cornwall). For marine data, free-air anomalies have been calculated from observed gravity values along marine survey lines. Line intersection errors between crossing lines and overlapping surveys have been used using network adjustment techniques. Free air anomalies have been calculated for sea-bottom stations. For land data, bouguer anomalies have been calculated from gravity observations at points of known height. In order to minimise the effect of topography, Bouguer corrections for the British Mainland have been applied using a density estimated for each station. Elsewhere a correction density of 2.67 Mg/m3 has been used. Corrections for the gravitational effect of terrain have been made where significant, and in a general extent to a radius of 48.6km. The data have been interpolated onto a 1km x 1km grid using a variable tension technique, and smoothed.