Information Board: The Geology of Sandy Heath (inside the
enclosure of 2 old trees)
As the name suggests, Sandy Heath is underlain by sand, named after the main
outcrop at Bagshot in Surrey where it was first described. Bagshot Sand was laid down in a shallow coastal sea about 50 million years ago. Most of this sand has since been removed by erosion although it still caps the London Clay on the high
ground of Hampstead Heath, Harrow-on-the-Hill and Epping Forest.
The sand is unsuitable for mortar, mainly because of its high iron content, but over the centuries it has been put to various uses such as sprinkling on floors of mediaeval houses and filling hollows and boggy patches in roads before they were cobbled or tarred over. On the Upper Fairground area, to the south side of Spaniards Road, it was used for filling sand bags during World Wars I and II. The hummocks on Sandy Heath today are the result of a more intensive usage. In the 1860s Sir Thomas Maryon Wilson was thwarted from building on the Heath so instead he dug it up and sold up to thirty cart loads a day to the Midland Railway for
a new track running out of St. Pancras. Within this small enclosure two trees still
stand that pre-date the quarrying, all the others are woodland that has re-established
itself since quarrying finished and now provide an interesting area of the Heath.
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