A railway cutting in Hornchurch might not seem the most obvious place to open your eyes to the shaping of Britain but this seemingly insignificant site on the Romford to Upminster single line is one of the most important Ice Age sites in Britain. Its full significance is being revealed following a joint project between Network Rail and Natural England to restore the site.
The Site of Special Scientific Interest (SSSI) will feature in ‘The Birth of Britain’, a new Channel 4/ National Geographic International series, presented by Tony Robinson, to be broadcast on Channel 4 from 17th January 2011.
Hornchurch’s importance lies in the geological deposits that it reveals. The ‘Hornchurch Till’ or glacial deposit, contains Jurassic rocks and fossils carried here from the Midlands, indicating that the site marks the Southernmost extent of the Anglian ice sheet which covered much of Britain, reaching north London around 450,000 years ago.
The railway cutting is also the only location to clearly reveal that the river gravels of the modern Thames directly overlie the glacial deposits, indicating that the area was covered by the river after the glacier had retreated. This demonstrates that the Thames was diverted south from its former course through East Anglia by the ice sheet, into its present valley through London.
The discovery of the site was made during construction of the Romford to Upminster branch line in 1892 by the geologist T.V. Holmes, of the Essex Field Club. Re-excavation of part of a section in the cutting in 1983 confirmed the site’s significance as a resource for geologists studying the Ice Age and the impact of former climatic changes on our landscapes.
In recent years the site had become overgrown. Thanks to collaboration between Natural England, geological specialists and Network Rail’s local maintenance team in Romford, extensive clearance work has revealed the cutting face and the trench excavated in 1983.
Emily Dresner, Land Management and Conservation Lead Adviser for Natural England in London said: “It’s been amazing to see the history of the site uncovered. The latest achievement is the mapping of the precise join between the till and the overlying Thames gravels along the length of the cutting – the key feature which Holmes would have seen in his day.
“Network Rail’s people have been invaluable in supporting the restoration work and helping us to ensure the site is accessible.”
Natural England and Network Rail are currently agreeing a long-term management plan to ensure the geology of Hornchurch Cutting is preserved and available for study by future geologists.
John Whitehurst, Anglia infrastructure maintenance director for Network Rail, said: “Helping protect and preserve one of the most important Ice Age sites in the country just yards from a 21st century railway has been an exciting challenge for my team. We’re well used to preserving railway heritage but it’s not often we’re asked for help with a site that’s more than 450,000 years old!
“The logistical challenges of working alongside a live railway are great but we’ve been able to arrange access to the site for Natural England and the scientific community without any impact on passenger services. I know Natural England appreciate the efforts my team have gone to and we look forward to continuing to work together on this exciting project.”
Hornchurch Railway Cutting SSSI will feature in the ‘The Birth of Britain’s’ episode ‘Ice’ on 24th January 2011 at 8pm on Channel 4.