This layer of the Map based index (GeoIndex) shows the location of records of boreholes, shafts and wells from all forms of drilling and site investigation work. Some 850,000 records dating back over 200 years and ranging from one to several thousand metres deep. Currently some 50,000 new records are being added to the collection each year. The dataset available via the GeoIndex is a snapshot, taken at a particular date, of the Single Onshore Borehole Index. Although the GeoIndex is updated at regular intervals more information may be available than is shown.

The map based index includes outlines for some 8,000 opencast coal prospecting sites dating from the 1940s until the mid 1990s. The index leads to information on the records of some 1 million boreholes (additional to those shown in the Borehole Records layer) drilled during site exploration and also the accompanying plans and other data, all filed in 3,618 boxes. The sites include those that have been drilled and not worked and also those that have been exploited. The original data, hardcopy maps, were received from the Coal Authority in 2001.

This layer of the GeoIndex shows the location of available 1:50000 scale digital geological maps within Great Britain. The Digital Geological Map of Great Britain project (DiGMapGB) has prepared 1:625 000, 1:250 000 and 1:50 000 scale datasets for England, Wales and Scotland. The datasets themselves are available as vector data in a variety of formats in which they are structured into themes primarily for use in geographical information systems (GIS) where they can be integrated with other types of spatial data for analysis and problem solving in many earth-science-related issues. Most of the 1:50 000 scale geological maps for England & Wales and for Scotland are now available digitally as part of the DiGMapGB-50 dataset. It integrates geological information from a variety of sources. These include recent digital maps, older 'paper only' maps, and desk compilations for sheets with no published maps.

This layer of the map based index (GeoIndex) shows the location of onshore UK boreholes known to BGS that have digital or paper geophysical borehole logs. The details given for each borehole are, the name of the borehole, the grid reference and the format, ie. paper or digital. Scattered distribution of boreholes, locally dense coverage, few logs from Scotland. The GeoIndex is updated at regular intervals but more information may be available than is shown at any one time.

This layer of the map based index (GeoIndex) shows sites where regularly monitored rest water level data are available, usually covering a long time period. The data shows seasonal fluctuations in the water table and responses to periods of high or low rainfall.

This layer of the map based index (GeoIndex) shows the location of earthquakes within the UK. The historical catalogue has been compiled, in general, from macroseismic observations (ie felt effects). Before 1700, only earthquakes with magnitudes of 4.0 ML or greater are included. After 1700, all known events with magnitudes of 3.0 ML or greater are included together with some other, smaller ones. Accuracies of magnitude, location, and origin time vary with the quality of information available for this period as they do for instrumental measurements in the post 1970 period. In that case, variations are largely a function of the seismograph station coverage, which has been improving up to the present day.

This layer of the map based index (GeoIndex) shows the availability of 1:50000 series paper geological maps. For England and Wales (and Northern Ireland), map sheets normally cover an area 30 km east-west and 20 km north-south; in Scotland the coverage is 20 km east-west and 30 km north-south. The 1:50 000 geological map grids are based on an early Ordnance Survey 1:63 360 (one inch to one mile) scale map grid and are not related to the current Ordnance Survey 1:50 000 map sheets. Maps are normally available in both flat and folded formats.

This layer of the map based index (GeoIndex) shows the locations of the Mineral Reconnaissance Programme Reports within Great Britain. The Mineral Reconnaissance Programme (MRP), funded by the Department for Trade and Industry (DTI), carried out mineral exploration reconnaissance in Great Britain between 1972 and 1997. The programme provided geological, geochemical, geophysical, mineralogical and metallogenic information on prospective areas in Britain. Work was carried out at various scales, from regional reconnaissance surveys or appraisal, to the drilling of a geochemical or geophysical anomaly. Projects were multidisciplinary, and used a combination of tried and tested methods, together with innovative techniques arising from research and development programmes. By the end of the Programme in 1997, 146 MRP reports had been issued covering localities across the UK. The programme was very successful in that more than half the projects reported attracted significant commercial follow-up resulting in the discovery of many new prospects. The reports themselves are being made available, for free, to downlaod over the next twelve months.

This layer of the map based index (GeoIndex) shows the locations of panned drainage sediment samples. At most drainage sampling sites a panned heavy mineral concentrate is collected from the <2mm sediment fraction using a wooden dulang pan. For the Mineral Reconnaissance Programme these pans would be routinely analysed for mineral exploration purposes. The G-BASE project collects them at every drainage site but does not routinely submit them for chemical analyses and the samples are archived. Usually they are inspected when collected with a hand lens and the presence of mineralisation or contamination is recorded in the site information on field cards. The MRP has collected heavy mineral concentrates from some 33,000 drainage sites and analysed these for a variety of elements (predominantly by XRFS) including Ag, As, Au, Ba, Bi, Ca, Ce, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Sn, Sr, Ti, U, V, W, Zn and Zr.

This layer of the map-based index (GeoIndex) shows the boundaries of the G-BASE (Geochemical Baseline Survey of the Environment) project mapping areas, which are reported as geochemical atlases. The majority of atlases are for stream sediment, with data on stream water and soil included where available. Separate stream sediment, soil and stream water atlases have been published for Wales. Hard copy atlases are available for Shetland, Orkney, South Orkney and Caithness, Sutherland, Hebrides, Great Glen, East Grampians, Argyll, Southern Scotland, Lake District, NE England, NW England and N Wales and Wales. Digital atlases/map products are available for the Clyde Basin, Central England, London Region and SW England. National digital atlas products are available also.