This layer of the map based index (GeoIndex) shows the location of hydrocarbon wells known to BGS. Exploration for hydrocarbons by drilling began in the 19th century and locations were recorded in latitude/longitude until about 1960. These locations have been converted to national grid. The majority of the wells have formed part of basin studies by BGS and are therefore reliably located. There may be some discrepancies in location data between various databases, originating from project modifications and which original source was preferred.

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.

The surveys shown on the map based index (GeoIndex) include; Analogue airborne magnetic surveys of Great Britain for the Geological Survey (GSGB), commercial analogue survey of North Sea by Aeroservices Inc, subsequently digitised by BGS, commercial digital (+ one analogue) surveys off NW/N/NE of Britain by Huntings Geology and Geophysics, purchased outright by BGS and Local surveys, digital and analogue aeromagnetic (+ other methods) surveys for BGS and commercial companies.

This layer of the map based index (GeoIndex) shows the availability of 1:63360 scale geological maps. The maps are available for most of England and Wales and show early geological mapping covering the OS Old Series one inch map sheet areas.

This layer of the map based index (GeoIndex) shows the locations where stream sediment samples are collected under the G-BASE (Geochemical Baseline Survey of the Environment) programme at an average density of approximately one site per 1.5 km square. Analytical data for the minus 150 micron fraction of stream sediment samples are available for some or all of the following elements by a variety of analytical methods (now predominantly XRFS): Mg, P, K, Ca, Ti, Mn, Fe, V, Cr, Co, Ba, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Pb, Bi, Th, U, Ag, Cd, Sn, Sb, Cs, La, Ce, Ge, Sc, Se, Br, Hf, Ta, W, Tl, Te and I. Stream sediment samples were also collected by the now defunct MRP programme and analytical data for the minus 150 micron fraction of samples is available for a variety of elements including Ag, As, Au, Ba, Bi, Ca, Ce, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Sn, Sr, Ti, U, V, W, Zn and Zr. Some of the MRP samples may have undergone several stages of analysis, some for inclusion in the G-BASE project. The samples may have been assigned a different sample number but will plot at the same site. Data is available for most Great Britain, apart from some parts of Southern England which have yet to be surveyed.

An index to over 600 ground geophysical surveys carried out in the UK for a variety of projects. A large number of these surveys were done in conjunction with the DTI Mineral Reconnaissance Programme in the 1970's and 80's, and many others were carried out at the request of BGS field mapping groups. Information held describes the survey objective, location of measurements, geophysical methods and equipment used, reports and publications, storage locations of data and results (for analogue and digital data), dates and personnel. There are two datasets; one shows the outline of the survey areas, and the other shows the actual survey lines within each area.

This layer of the map based index (GeoIndex) shows the path the survey ship took whilst undertaking the ship gravity, magnetic and bathymetry survey. This index is based on data from approximately 350,000 line kilometres of multi-instrument geophysical survey lines. The data itself includes seismic, sonar, magnetic, gravity, echo sounder, multibeam bathymetry and navigation data, both in digital and analogue format. The data were primarily collected by BGS and the collection also includes additional third party data.

This layer of the map based index (GeoIndex) shows unadjusted ship gravity, magnetic and bathymetry data acquired by BGS as part of its Offshore Reconnaisance Mapping Programme. This programme commenced in 1967, and was funded mainly by the Department of Energy. Unadjusted ship gravity and bathymetry data from various commercial and academic surveys between 1965 and 1994. Confidential M.O.D Hydrographic Office integrated ship gravity and magnetics surveys of NW Europe marine areas for which BGS acts as agent. Network adjusted gravity and magnetic compilations of data from BGS and non-BGS sources.

This layer of the map based index (GeoIndex) shows the location, with basic metadata, of selected DECC (Department of Energy & Climate Change) offshore hydrocarbon wells. The source data for this layer was downloaded from the DECC website at www.og.decc.gov.uk/information/maps_offshore.htm. These are DECC owned data and information and supply of the actual data is through the DECC release agents.

This low-resolution image has been produced from BGS airborne and marine magnetic 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. A published coloured shaded relief map, using the full resolution of the data and produced at a scale of 1: 1500 000, is available. The map covers a larger area than this image, and includes additional data from other sources. The data used to compile this image are available in various forms for academic and commercial licensing. The data from surveys covering the UK mainland have been digitised from their original analogue form. Elsewhere data were acquired digitally. Standard methods of processing were used to remove diurnal and secular variations and to minimise line intersection errors. While efforts have been made to remove artefacts from the data, some may remain between adjacent datasets. Generally anomalies over man-made structures have not been removed. The data have been interpolated onto a 1km x 1km grid using a variable tension technique, and smoothed.