The Lea Valley’s Return to Nature
The following passage is a short extract from Jim Lewis’s new book, From Ice Age to Wetlands: the Lea Valley’s Return to Nature. This book is due to be published by Libri Publishing Limited in autumn 2017.
Scientists have estimated that the earth is around 4,600,000,000 years old. Compared to this, the Lea Valley, which was formed 1,000,000 to 1,800,000 ago, during the four glaciations (ice ages) of the Pleistocene Epoch, is a mere newcomer. The last ice sheet, which geologists have calculated advanced from the north to a line that extended west-east across Britain from south Wales through Finchley to south Essex, retreated about 11,000 to 10,000 years ago. Water created as the ice melted (melt waters) brought down deposits of sand, gravel and clay that eventually formed the flat marshy flood plain of the lower Lea Valley. Evidence of this can be seen today in places like Walthamstow and Tottenham marshes. Indeed, we are fortunate that our recent ancestors named one of these areas Walthamstow Common Marsh and used it for growing hay and grazing cattle. This has allowed much of the Marsh’s ancient character to remain. Since 1985 the area has been designated a Site of Special Scientific Interest (SSSI) and supports some 400 different species of insect, plant and animal.
Towards the northern end of the Lea Valley, which, unlike its southern counterpart, has not remained undisturbed, there is evidence of a much earlier period going back many million of years. During the extensive gravel excavations that took place in the twentieth century, several types of fossil and a variety of prehistoric animal remains were unearthed, providing clues about the valley’s early history for the archaeologists to study. The method used for extracting gravel is very much an industrial operation, which has meant that many of the ancient finds that have come to light failed to receive the same level of sensitive recording and care as would have been expected from a planned archaeological dig. However, on the plus side, since gravel extraction has now ceased in the upper Lea Valley the aftermath has created a number of water features, which are home to a variety animals, insects and plants. Not to mention the different species of fish, which inhabit these man-made lakes now that nature has begun, and continues, to re-establish herself.
Copyright: Dr Jim Lewis (Contributory International Professor, Marian University, Indianapolis, Indiana)