Description: The Hemlock Stone is an inselberg, – an isolated pillar of 200 million-year-old New Red Sandstone, which stands on the eastern slope of Stapleford Hill, Bramcote near Nottingham. It has been identified that the inselberg consists of, roughly in equal proportions, two stratified layers different native bedrock laid down during the Triassic Period. Both rock types are classified as being a part of the New Red Sandstones of the Sherwood Sandstone Group.
a. Top layer: Nottingham Castle Sandstone, a medium to coarse-grained sandstone, in which the grains are strongly cemented together by baryte.
b. Bottom layer: Lenton Sandstone, a very fine-grained and less well cemented structure.
The Castle Sandstone top of the inselberg ‘overhangs’ the Lenton Sandstone giving the whole a rather mushroom like appearance. This effect has been caused by the geological process known as ‘differential erosion’ where the two layers have eroded away at different rate in accordance with their density and composition.
There are three possible origins for the Hemlock Stone:
(1). By far the simplest of these is that it is a natural geological formation created by long term erosion of the surrounding landscape exposing a deposit of Castle Sandstone, later acted upon by the forces of differential erosion.
If this can be proven to be the case, then the inselberg’s age can be counted on a geological time scale rather than an historical one. This origin can be directly compared to at least one of a group of inselbergs on the North Yorkshire Moors known locally as The Bride Stones.
(2). The alternative to the natural geological origin of the feature is that it is the product of human hands. This is first suggested or rather inferred by the 18th century antiquarian William Stukeley. it is Stukeley who provides the first historical reference to the Hemlock Stone in his book ‘Itenerarium Curiosium’ published in 1724. In this work, in a brief and passing reference to the Stone Stukeley describes it as being: “….probably the result of bye-gone quarrying”.
Because of the amount of sandstone quarrying carried out in the area around the Stone it is commonly believed therefore that the feature is nothing more than the mere bi-product or waste of a sand-quarry. However, circumstances surrounding the account indicate that Stukeley never actually visited the site. The use of the word probably suggests both non-committal on his part and the fact that he was unable to obtain a positive opinion from others. Like other antiquarians of the time, Stukeley uses the term ‘bye-gone’ times to indicate a period beyond living memory. If Stukeley’s assumption is correct, then this would place any potential quarrying of the area to a very early date. At such a date there would have been very little demand at that time for the amount of sand that would have been quarried, especially with sand-rich Nottingham so close by. This would suggest that the Stone was the product of deliberate quarrying.
(3). Examination of Stukeley’s comment leads to the third potential origin theory for the Stone. Given folkloric and other historical references and possible archaeological evidence, if indeed, the Hemlock Stone is proven to be the product of quarrying, then this would have been in the remote past (Neolithic or Bronze Age) This would mean that the Stone is in its own right the deliberate product of quarrying rather than an accidental or unwanted bi-product.
If this origin proves to be the case then it would make the Hemlock Stone unique among the pre-historic monuments of northern Europe.