On Thursday February 14th, having opened all our cards and under grey skies, Ian, Mike and self, continued our foray into the Teme Valley and you know, sounds daft, but it really does feel like exploration when for us, checking out the rocks is a novel experience. Anyway, we headed first to St Marys, Stanford, to see if we could find on the ground evidence of the mapped Raglan Sandstones in the land above the church. At the spot under a spreading chestnut tree we did indeed find sandstone rocks but these were scattered about and could possibly have been from local building works although at the time we preferred not to see them that way. To us they seemed similar to the church and to local walls of the old rectory just across the road.
Travelling up the road by car, we entered Busk Coppice to show Mike the large quarry found on our last visit—did this supply the stone to St Marys’ Stanford, but where is the lime kiln that Mr Churchill the farmer had told us about?
We wandered about down into gullies keeping in mind that it would not be far from the Bishops Frome layer, here underlying the quarried rock, St Maughans sandstone. We gave up and called the farmer who directed us back up the track to a shooting platform and
goodness, there, not 3 metres from the trail, was a deep conical brick lined pit, a danger to anyone not seeing it, set in a levelled off terrace. On the terrace below was a substantial brick built arched construction leading into the terrace and under the cone. A magnificent example of an ancient kiln, a little the worse for wear and needing attention to remove trees and soil but other than that looked like it could be relit straight away. This would have been used to make lime for mortar for building and for the fields and was slap bang into the Bishops Frome limestone, the calcrete (fossilised soil) referred to in other posts. According to Mr Churchill, a farm worker by the name of Tommy Tucker used to live in the arched kiln. A little archaeological investigation sounds in order. Read Nils Wilkes fascinating study of Lime Kilns in Worcestershire HERE
So you burn limestone at 900C thus converting it from Calcium Carbonate to Quicklime and Carbon Dioxide, then you slake it with water making Calcium Hydroxide, known as lime putty, used as the base for a slow setting, traditional mortar still used in renovation work today.
That accomplished we went by car along the charming, twisty, switchback lane to just beyond Orleton until we reached the foot of Quarry Hill—the clue being in the name.
This is an outlier from the main escarpment. The geological maps show the limestone outcropping around the whole of the Bromyard plateau, with an island of it on top of Quarry Hill.
According to the maps the limestone was set in a sea of (Silurian) Raglan Mudstone only, and as we struggled up the wooded precipitous hillside littered with fallen trees, the redness of the soil seemed to indicate that this was the case. There were occasional obvious trackways contouring the slopes, signs of forestry work or perhaps quarrying, who knows? In the red roots of fallen trees we searched for stone as tell-tale of underlying rock and these at first were typical of Raglan sandstone. Continuing to force our way upwards to the very top we discovered a substantial area clearly shaped by human endeavour. There were no rock faces but the humps and bumps seemed to show that much of the top layer of limestone had been removed. We did uncover large stones set in a semi-circle, perhaps the foundation of a kiln?
Just down the slope, we chanced upon exposed bedrock and took samples. To our surprise these mirrored an earlier finding some way down the slope (that we had tried to ignore), of a coarse conglomerate, not what we expected at all. One was ruddy, the other light grey, found 3-400mm above one another in clear layers. The map shows (Devonian) St Maughans conglomerate in a number of places, but nowhere near this spot, and certainly none below the limestone. So how to explain this? We retrieved our samples, cleaned them and will set them before the oracle as soon as we can.