Geology Site Account
Harlow Puddingstone, HARLOW TOWN, Harlow District, TL42860898, Potential Local Geological Site
Site name: Harlow Puddingstone
Grid reference: TL42860898
Brief description of site:
Giant boulder of Hertfordshire puddingstone in an internal courtyard of office buildings. Access only with prior permission from the landowner.
A large boulder of Hertfordshire puddingstone 1.65 metres (5 feet 6 inches) high stands upright in the private quadrangle of the offices of Glaxo SmithKline (formerly BP House) in Third Avenue. It was discovered during construction of the building in 1966. Puddingstones are extremely hard rocks with an interesting history.
About 60 million years ago, shortly after the extinction of the dinosaurs, this boulder was part of a beach of flint pebbles on the coast of a subtropical sea. About 55 million years ago the sea had retreated and the layer of pebbles was situated beneath the soil in a hot, dry climate similar to that of the Kalahari Desert today. During this time the pebbles were cemented together by quartz, forming an incredibly tough layer of rock.
During the Ice Age, about half a million years ago, rivers and glaciers broke up this layer and scattered the fragments over Hertfordshire and Essex. This boulder is one of these fragments and the original flint pebbles can be clearly seen. Puddingstone is so called because the pebbles give it the appearance of a plum pudding. It is usually called Hertfordshire Puddingstone because these boulders are most commonly found in East Hertfordshire. Some puddingstone is very colourful and in Georgian and Victorian times it was often cut and polished to make jewelry and decorative items such as snuff boxes.
For security reasons the boulder is not accessible to the general public and can only be viewed by appointment.
The Harlow Puddingstone as found in 1966.
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