As the Quaternary glaciations gripped eastern England blanketing it in swathes of ice, torrents of subglacial meltwater carved a network of channels through the ice sheets and buried landscape partially superimposing themselves on pre-glacial river networks. Reaching depths of up to 100m, these buried channels produced a significant scar in our subterranean environment - one that often has no surface expression and which is of considerable consequence to modern hydrogeological processes and our understanding of the dynamics of ancient ice sheets. Where these channels were once enveloped by a great thickness of ice they are now in-filled and buried beneath more recent superficial deposits.
We cannot claim to be pioneers in uncovering these glacial features since several geologists identified the existence of palaeovalleys in East Anglia in the late 19th Century. It wasn’t until 1970 though that Austin Woodland, while working at the then Institute Geological Sciences (IGS – now British Geological Survey) collated information from water supply borehole records to map the distribution of the buried valleys in sufficient regional detail1. Now, with computer technology we are able to revisit Woodlands work to define in 3D the extent of these buried channels. In doing so, we are able to establish the inter-connections between the pre-glacial setting of central and eastern England, and the modern day hydrological regime.
This Sheet Explanation provides a summary of the geology and applied geology of the district covered by geological 1:50 000 Series Sheet 203 Bedford, published as a Bedrock and Superficial Deposits edition in 2010. The district lies in the south-east of the English Midlands, about 45 miles north of London and includes parts of Bedfordshire, Northamptonshire and Buckinghamshire.
This brief open-file report summarises the information available from the British Geological Survey (BGS), a component body of the Natural Environment Research Council (NERC), on the geology, hydrogeology and potential geological hazards of the proposed HS2 Route 3 within the Chesham and Amersham Constituency, and surrounding areas.
The report summarises the geology and hydrogeology of the district and highlights geological and hydrogeological considerations that may need further investigation along the route.
Further review and analysis of existing data and possible field investigation would be required to confirm details of the local geology.
The report was requested by Mrs Cheryl Gillan MP following a meeting with Dr Martin Smith, Head of Geology & Landscapes programme, on Monday 16th May 2011 at the offices of the Secretary of State for Wales in Whitehall.
Abstract The sedimentology, micropalaepntology and palynology of Lower Pleistocene sediments recovered from a borehole at Ormesby St Margaret, near Great Yarmouth, Norfolk, have been investigated. The sediments, consisting of a lower clay facies overlain by an upper predominantly sandy facies, were deposited in inner neritic environments. Micropalaeontological and palynologicalevidence allows comparisons with the nearby Ludham sequence but an unequivocal correlation cannot be made. The Ormesby Borehole sequence includes representatives of the Pre-Ludhamian to Early Pastonian stage interval and the presence of a late Pre-Ludhamian to late Baventian/Pre-Pastonian a hiatus. Foraminiferal faunas matched to grain size analysis are indicative of transportation and considerable post-mortem sorting.
A new stratigraphical model for the glacial deposits around Lowestoft, Great Yarmouth, North Walsham and Cromer (east of Weybourne and Edgefield) is presented, based on a
combined research programme by the British Geological Survey and the Department of Geography, Royal Holloway University of London. This stratigraphical model is founded
upon evidence derived from sedimentological descriptions, geological mapping and analytical lithological techniques including clast lithological analysis, derived pre-
Quaternary palynomorphs and heavy mineralogy. The previously accepted ‘North Sea Drift’ / ‘Lowestoft Formation’ scheme is abandoned in favour of four formations that relate to assemblages of till units and associated outwash lithofacies, the mapping of major discontinuities, and morpho- and tectono-stratigraphical associations. The new scheme consists of the Happisburgh, redefined Lowestoft, Sheringham Cliffs and Briton’s Lane formations.
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