Karst, GIS and geological hazard planning and management in Great Britain

The British Geological Survey (BGS) database of karst features for the United Kingdom include dolines, cave entrances, stream sinks, resurgences and building damage; data for approximately half of the country has so far been gathered. BGS makes and utilises digital geological map data, which includes lithological and stratigraphical information for bedrock and superficial deposits. By incorporating this digital map data with digital elevation slope models and karst data, BGS has generated a derived dataset assessing the likelihood of subsidence due to karst collapse. This dataset is informed and verified by the karst database and marketed as part of its GeoSure suite; the karst layer includes areas of limestone, chalk, gypsum and salt. It is currently used by environmental regulators, the insurance and construction industries plus the BGS semi-automated enquiry system. The karst database and GeoSure datasets can be combined and manipulated using GIS to make other datasets that deal with specific problems. Sustainable drainage systems, some of which use soak-aways into the ground are being encouraged in the UK, but in karst areas they can cause problems. Similarly, open loop ground source heat pumps may induce subsidence if installed in certain types of karst such as chalk with overlying sand deposits. Groundwater abstraction also has the potential to trigger subsidence in karst areas. GIS manipulation of the karst information will allow the UK to be zoned into areas suitable, or unsuitable, for such uses; it has the potential to become part of a suite of planning management tools for local and National Government to assess the long term sustainable use of the ground

Geology of the Syke House Farm area, Barwick in Elmet, Yorkshire

This report details a site visit to Syke House Farm [NGR: 439800, 438400], Barwick in Elmet, Yorkshire undertaken for the Environment Agency to investigate exposures and check the validity of the published geological maps. An open excavation proved the base of the Permian sequence and showed it to be about 15m further to the south than it is shown on the published maps. The excavation exposed weathered and purple-stained Lower Coal Measures Formation mudstone overlain by about 1.3m of fine to medium-grained sandstone of the Rotleigende Group, Yellow Sands Formation (formerly called the Basal Permian Sandstone). This was overlain by about 10m of dolomite belonging to the Zechstein Group, Cadeby Formation (formerly called the Lower Magnesian Limestone). The published map shows the area crossed by an approximately east-west trending fault downthrown to the north. On the north side of this fault line the exposure of Cadeby Formation dipped at 20 degrees in a northerly direction suggesting folding as part of a drag fold against the fault. In the southern exposure of the Cadeby Formation, the dip was to the south-east at about 24 degrees; here the sequence was more brecciated with slightly open fissures and a dip caused by cambering and collapse of the escarpment edge appears the most likely cause. The site had extensive made ground that was built up on the side of the valley; in places there was evidence that some of the bedrock had also been excavated, especially where the exposures were visible. Made ground and excavations were also observed in the floor of the valley where an elongate lagoon was being filled with tipped material. Copple Syke Spring was observed, but in a slightly different place to that shown on the published Ordnance Survey map

The geology, hydrology and stability of the landslips between Otley and Old Pool Bank, West Yorkshire

Geological survey of the landslips east of Otley to Old Pool Bank. Survey of springs and stream sinks along with information about active landslide movements

Building damage classification and recording scheme for subsidence and landslide mapping

Building damage due to subsidence and landslips within Great Britain is considerable. The degree of damage depends on the position of the building, the size of the unstable land area and the amount of movement. Recording building damage permits the delineation of areas of unstable land and the degree of damage gives an indication of the severity of the problem. This technical report reviews the schemes that have been used in numerous situations for recoding damage due to subsidence, landslips and earthquake damage. It compares the classifications and proposes a unified scheme that is the foundation of building damage recording in BGS. Seven categories are proposed ranging from 1, which is barely perceptible through 5, which is very severe with considerable damage to 7, which is total collapse

Revised geological maps of Darlington based on new borehole information: explanation and description

The geology of the Darlington area has been revised based on the interpretation of new borehole information and a re-examination of archival data. The Permian Zechstein Group has been mapped through the district where it forms a series of easterly-dipping formations. These strata have been folded and an easterly-plunging syncline, faulted on its southern side, is mapped through the town of Darlington. This fold structure is partially modified by the dissolution of gypsum in the sequence resulting in the partial collapse and foundering of the strata. A series of maps is presented showing the revised geology, rockhead, drift thickness and the thickness of the gypsum sequence present at two horizons; the Hartlepool Anhydrite (present in the Edlington Formation) and the Billingham Anhydrite (present in the Roxby Formation). A series of five structure contour maps are presented illustrating the fold and fault structure of the area

Tadcaster Magnesian Limestone 3-D borehole interpretation and cross-sections study

This report was prepared under contract to the Environment Agency and describes the geology of the area surrounding Tadcaster in North Yorkshire. The work was commissioned to investigate the local geology and construct 3-D cross-sections from borehole and surface information. Approximately 1200 boreholes were utilised for the work and these ranged in depth from a few metres to 350m. Five cross-sections were constructed; three WSW-ENE trending sections and two NNW-SSE trending sections all to a depth of 250m below OD. In addition, a series of thematic maps were generated from the lithological component of the digital borehole data. Total superficial aquifer and superficial aquitard maps show how the lithological nature of the superficial sequence varies across the area. Rockhead elevation and superficial thickness maps indicate where the bedrock aquifers outcrop or are near to the ground surface. The east side of the Vale of York in the vicinity of Tadcaster is underlain by a sequence of Permian and Triassic rocks overlain in part by thick superficial deposits dating mainly from the last Ice-Age. The Permian rocks comprise two magnesian limestone aquifers separated by sequences of gypsum/anhydrite and gypsiferous mudstones. The overlying Triassic rocks comprise the major Sherwood Sandstone aquifer. The western part of the area consists of mainly exposed bedrock (Permian dolostone and dolomitic limestone), but the eastern side where the Sherwood Sandstone Group is present has a thick cover of superficial deposits including moraines, glacial lake deposits and alluvial deposits

An enhanced classification of artificial ground

This report describes a detailed scheme for the mapping and recording of artificial ground. It presents codes and descriptions that underpin the entries in the British Geological Survey stratigraphical lexico

The stratigraphy, correlation, provenance and palaeogeography of the Skiddaw Group (Ordovician) in the English Lake District

A new lithostratigraphy is presented for the Skiddaw Group (lower Ordovician) of the English Lake District. Two stratigraphical belts are described. Five formations are defined in the Northern Fells Belt, ranging in age from Tremadoc to early Llanvirn. They are all mudstone or sandstone dominated, of turbidite origin; in ascending order they are named the Bitter Beck, Watch Hill, Hope Beck, Loweswater and Kirk Stile formations. Two formations are defined in the Central Fells Belt, ranging in age from late Arenig to Llanvirn. These are the Buttermere Formation - a major olistostrome deposit - overlain by the Tarn Moor Formation, consisting of turbidite mudstones with volcaniclastic turbidite sandstone beds. A revised graptolite and new acritarch biostratigraphy for the Skiddaw Group is presented with eight graptolite biozones and thirteen acritarch assemblages and sub-assemblages. The provenance of the group is assessed from detailed petrographical and geochemical work. This suggests derivation, in the early Ordovician, largely from an old inactive continental arc terrane lying to the south-east, with the appearance of juvenile volcanic material in the Llanvirn. Comparisons and correlations of the Skiddaw Group are made with the Isle of Man and eastern Ireland

Environment Agency: Durham Permian Sections

This report describes six sections constructed through the Permian and Carboniferous sequence in north-east England. The main north-south section (split into two parts) extends from near Sunderland in the north to near Darlington in the south. Four east-west sections are situated in the north, centre and southern parts of the area. In addition, a short north-south section is located just to the west of Hartlepool. The sections have been constructed to a depth of 300m and created from borehole and map information compiled using the GSI3D modelling software

Multidisciplinary fieldwork training in a professional geoscience environment: Quaternary mapping, landscape literacy and hazard identification

This report was produced to describe the Quaternary geology of north-east England and how it can be interpreted and mapped. It is based on previous manuals for Quaternary geology mapping training produced by the British Geological Survey. It gives insight into the glacial and periglacial processes of the Yorkshire coast and the Vale of York