In the summer of 2023, as part of the Fellfoot Forward project, a team of local volunteers worked alongside geologists from the Cumberland Geological Society and Cumbria Geoconservation Group to undertake a geological survey of the Long Meg stone circle. The results, subsequently enhanced through further work by a small team of geologists, are fascinating, and further work is ongoing. An interim report is available here. At the same time as the geological survey, a condition survey was completed, looking in particular at damage caused by burrowing bunnies; a separate report on this work can be seen here.  

Geological survey in progress
Geological survey in progress at Long Meg, May 2023

The geological survey included detailed study of each Daughter. It was noted that most of the Daughters appear to be set within a low earthen bank; in the past it had been thought that this could have been a result of ploughing over recent centuries, but now it seems more likely that it was an original feature of the site. This implies that the perimeter of the circle was laid out early in the construction process, with the stones later being inserted into the bank. Possible implications of this are considered in the geological survey report.

Detailed analysis of Long Meg herself has confirmed that she is of Penrith sandstone, and a probable actual location from which she was taken has been identified, though further work is needed to confirm this. At this location, a number of large slabs of red sandstone have fallen from the river cliffs to lie vertically immediately adjacent to the river; Long Meg may well have been one of these.

The Daughters are all confirmed as glacial erratics, dumped by ice in the Eden Valley during the ice age. Each is unique, with its own characteristics which would not have been lost on those transporting them to the circle. The majority of those which could be accurately measured (ie excluding those which have fallen, for which original size and shape cannot be established) fall within a restricted size range, with maximum circumferences or girths (measured parallel to the ground) of 400 – 580 cm. 15 Daughters fall within this range, with only two larger and seven smaller. However, as we don’t know the size range of potentially available erratics, the implications of this are uncertain.

42 Daughters are characterised as of the Borrowdale Volcanic Group (BVG), from the central Lake District. They display much variation, on the basis of which they are divided into three subgroups.

22 Daughters are classed as Threlkeld Microgranite, with a source just south of Blencathra (Saddleback). Many of these contain distinctive xenoliths (inclusions) of much older Skiddaw slate.

It may be significant that Blencathra is a very distinctive feature of the western horizon seen from Long Meg, and the Lake District is similarly visible to the south-west. Neolithic people knew their landscape intimately, and may well have been aware of the places where such stone occurred as bedrock.

The other four Daughters are white granite, possibly Skiddaw Granite, or from south-west Scotland. Of these, two may mark the midsummer sunrise and sunset when seen from the centre of the circle; further work is needed to check this.

Remarkably, although camouflaged by millennia of weathering and lichen growth, where the colour of the BVG and Threlkeld Microgranite Daughters could be ascertained, they are almost all various shades of green. Quite possibly, if they were dug out the ground prior to being moved to the site, and thus had not been subjected to millennia of Cumbrian weather, they could all have appeared much greener than they do today at the time they were originally set up within the circle.

Exposed green rock in one of Long Meg’s daughters

It is interesting to note that earlier survey of erratics in the Eden Valley failed to record any BVG boulders in natural locations within several kilometers of Long Meg, though erratics of other lithologies are present. This could be interpreted as suggesting that the land has been cleared of all visible BVG boulders; perhaps they were all moved to Long Meg during the Neolithic.

Rapid assessment of a few roadside piles of boulders ploughed up in fields near Long Meg over recent years suggests that many such boulders (all smaller than the Daughters) are BVG or Threlkeld microgranite. This supports the idea that the boulders are erratics, having been dumped here by ice within the boulder clay where they lay buried until disturbed by modern ploughs.  

People sometimes ask why there is no Shap Granite at Long Meg, given that erratics of it have been recorded locally. The answer may simply be that it is the wrong colour; the people building the stone circle only wanted green stones. Possible implications of this are considered in the geological survey report. There is still further work to be done to characterise and source all the Daughters, but the key archaeological implications of the recent geological survey are clear. The Daughters are all glacial erratics, presumably collected from the surrounding landscape and dragged to the site, and almost all are various shades of green.