OR/15/068 A preliminary 3D model of post- Permian bedrock geology in the Vale of Pickering, North Yorkshire, UK Groundwater Programme Open Report OR/15/068 OR/15/068 OR/15/068 BRITISH GEOLOGICAL SURVEY GROUNDWATER PROGRAMME OPEN REPORT OR/15/068 A preliminary 3D model of post-Permian bedrock geology in the Vale of Pickering, North Yorkshire, UK Andrew J. Newell, Robert S. Ward & Mark W. Fellgett Contributor/editor J F Ford The National Grid and other Ordnance Survey data © Crown Copyright and database rights 2016. Ordnance Survey Licence No. 100021290 EUL. Keywords Vale of Pickering, bedrock geology, structure Front cover Bedrock geological model of the Vale of Pickering Bibliographical reference ANDREW J. Newell, Robert S, Ward & Mark W. Fellgett. 2016. A preliminary 3D model of post- Permian bedrock geology in the Vale of Pickering, North Yorkshire, UK. British Geological Survey Open Report, OR/15/068. 23pp. Copyright in materials derived from the British Geological Survey’s work is owned by the Natural Environment Research Council (NERC) and/or the authority that commissioned the work. You may not copy or adapt this publication without first obtaining permission. Contact the BGS Intellectual Property Rights Section, British Geological Survey, Keyworth, e-mail [email protected]. You may quote extracts of a reasonable length without prior permission, provided a full acknowledgement is given of the source of the extract. Maps and diagrams in this book use topography based on Ordnance Survey mapping. © NERC 2016. All rights reserved Keyworth, Nottingham British Geological Survey 2016 OR/15/068 BRITISH GEOLOGICAL SURVEY The full range of our publications is available from BGS shops at British Geological Survey offices Nottingham, Edinburgh, London and Cardiff (Welsh publications only) see contact details below or shop online at www.geologyshop.com BGS Central Enquiries Desk Tel 0115 936 3143 Fax 0115 936 3276 The London Information Office also maintains a reference collection of BGS publications, including maps, for consultation. email [email protected] We publish an annual catalogue of our maps and other publications; this catalogue is available online or from any of the Environmental Science Centre, Keyworth, Nottingham BGS shops. 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Terrain model based on Ordnance Survey OSTerrain50 (OpenData). ............................................................................................ 5 Figure 3 Terrain model (OSTerrain50) with the colour ramp clipped to elevations between 0- 35 m. All elevations greater than 35 m are shown as grey. The area highlighted by the colour ramp broadly approximates to the area of the glacial Lake Pickering, although at maximum this may have reached an elevation of 69 mAOD (Foster, 1985). The clipped colour ramp clearly shows the topographic sill formed from glacial till along the North Sea coast, the sands and gravels of the Pickering delta and the flat low relief central part of the Vale of Pickering that is underlain by lacustrine clay. ............................................................. 6 Figure 4 Chronostratigraphy and lithostratigraphy of Permian to Cretaceous bedrock units in Yorkshire (DECC, 2013) with arrows showing the ten horizons that have been included in the geological model. ................................................................................................................ 7 Figure 5 Outcrop bedrock geology of the VoP. Map based on BGS DiGMapGB-50 simplified by dissolving most units into their lithostratigraphical groups...................................................... 8 Figure 6 Perspective view across the western end of the Vale of Pickering from the NW. See Figure 5 for key to colours of geological units. Note the prominent step in the topography formed by the limestones of the Corallian Group shown in blue. ............................................ 9 Figure 7 Configuration of the SKUA-GOCAD stratigraphic column used in the modelling showing modelled horizons, geological units and stratigraphic contacts. .............................. 10 Figure 8 Distribution of wells (yellow spheres) used in the geological model. See Figure 7 for key to geological units. ........................................................................................................... 11 Figure 9 Example of a well section used to place and correlate well stratigraphic markers (formation tops) by using evidence from geophysical logs and borehole cutting returns. Section is flattened on the top of the Corallian Group. .......................................................... 12 i OR/15/068 Figure 10 Example seismic interpretation map modified from Kirby et al. (1985). This map shows structure contours on the top of the Corallian Group. Contours are isochrons in 20 ms intervals. Blue-shaded areas show the crop of the Corallian Group and green-shaded areas show the crop of the Chalk Group. ......................................................................................... 13 Figure 11 Plot of two-way travel time (taken from Top Corallian map of Kirby et al. 1985) against co-located well marker depth (m) for top of the Corallian Group. ............................ 13 Figure 12 Fault network used in the model shown inside the model bounding box. Red lines show faults on BGS 1:50000 geological maps. ...................................................................... 14 Figure 13 Example of BGS DiGMapGB-5 geological linework fitted to Ordnance Survey OSTerrain50 digital elevation model on the southern flanks of the Nork York Moors. ........ 14 Figure 14 Map showing the distribution of cross-sections (black lines) used in the construction of the geological model. Yellow dots are well locations. For colour key to bedrock geology map see Figure 5. .................................................................................................................... 15 Figure 15 Example of a cross-section showing wells, faults and stratigraphic horizons. See Figure 7 for key to geological units. ....................................................................................... 16 Figure 16 Geological model shown with five times vertical exaggeration. Vertical dimension covers approximately 2.5 km. Note the deep graben structure to the north of the Langtoft Fault and the unconformity at the base of the Chalk Group & Hunstanton Formation (shown in green). See Figure 7 for key to geological units. ............................................................... 16 Figure