Curator's choice - Natural history

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Geology and Topography

Various fossils are featured in the display on Wimbledon’s topography and geology. Some 100 metres of London Clay underlie Wimbledon, laid down under a shallow tropical sea some 45 million years ago. Clay soils are found on the steeper slopes down from the high plateau of Wimbledon towards the Beverley Brook and Wandle. There is a large fossil Nautilus, typical of the London Clay.

Other fossils arrived in Wimbledon more recently; they were found in the gravels of the high level plateau, which dates from the time of maximum glacial advance some 400,000 years ago, but the fossils have been transported in river gravels from much older rocks upstream of London.

In those times, the Thames meandered over a flat floodplain, the largest surviving remnant of which is found on the high land of the Common and Village. The soils of this plateau have had their nutrients leached away downhill over those 400,000 years, accounting for the poor soils of the heathlands and “acid grassland” that dominated the flat parts of the Common until recently.

The small stature and slow growth of the invading birch and oak in these areas reflects the poor growing conditions. The more fertile lower land near the Beverley Brook and Wandle is also too recent to hold local fossil material but, like the plateau, they have fossils brought downstream in the two rivers, or eroded from the edges of the plateau.

There is a link between the soils of these areas and the land use documented in Milne’s Land Use Map, surveyed around 1795 and on display elsewhere in the Museum. The infertile plateau had the “waste” of the common and the private parks of city gentry. The next in order of fertility was some poor grazing land at the highest points of the clay slopes, but below that there was woodland or arable crops and meadowland on the most fertile land in the river floodplains.