Members Evening June 1st 15

The first members’ evening that we have held and it was a success, so will repeat. Relaxed atmosphere, smorgasbord of topics, short, illustrated presentations and free, yes free, cheese, crisps, biscuits and a glass of wine.

First we heard from David, Ingrid and John a totally non-technical account of their recent visit to Arouca, a geopark in northern Portugal, where good contacts with the geopark team were made and some of the exceptionally well presented sites visited. Arouca with substantial European and regional Portuguese funding is developing an envied park, conserving and celebrating local geology and with it amplifying trades and crafts that would otherwise probably die out. Similar but on a larger scale to our plans for the Teme Valley. Bordering communities eye the project and make noises as to how they can join in but we understood that this is not really part of Arouca’s plan. Famous firstly for the giant trilobite fossils mentioned in Prof. Richard Fortey’s book, ‘Survivors’, of equal international status is the small area of nodular granite–known in Portuguese as the rocks that give birth (Pedras Parideiras). The process of their formation is not really understood, but basically within a matrix of granite in an area no larger than 1 square kilometre, many millions of black ellipsoid nodules are to be found. Owing, it is believed, to the differential expansion of the light coloured granite and the dark nodules, the ellipsoids gradually release from the parent rock and appear loose on the surface. One can only imagine the mystery of this in the minds of a rural and uneducated populace. The general bedrock of the Arouca Geopark is granite along with Ordovician Slates but on THIS site there is a much more detailed description. The countryside is rugged, provides excellent walking on well marked trails and abounds in drifts of colourful wild flowers.

During our stay, David had one or two personal adventures that left Ingrid and me scratching our heads. The more costly was the loss of his wallet with credit cards, driving licence and around £90. Tracing it in English by telephone to Portugal was tricky. Its ultimate fate, destruction at the hands of those who serve us–i.e. the British Consul and team, convinced us once again that the expectation of help from our overseas officers is a triumph of hope over experience. Pictures (on external site, click down arrow on right and select slideshow)

Second up were free cheeses and bikkies plus a glass or two of wine and time to look at small displays set up by Georgia with her wonderful textiles and books, Arouca with maps, books and rocks and such colourful minerals from Margaret–thanks all.

Ian (Fairchild) related the tale of fairly intrepid exploration into one of the dingles in the Teme valley at Stanford. A good friend Robin Dean (churchwarden of St Marys Stanford) owns around 20 acres of what is now VERY rough ground but was, in the old days, an orchard (it seems). Robin should really get his mower out.
The challenge in pouring rain, was to walk up the bed of Fall Dingle to one of its waterfalls, checking out rocks and plants on the way. Bits of tufa had been seen and Bishops Frome too, as well as substantial blocks of Raglan Sandstone and softer mudstone, chiselled out by the stream, innocent enough on the day but fearful in flood judging by the massive trees lodged in the bed. En-route we noticed seepages building tufa on the banks of the stream, clear indication that the limey nodules of the Bishops Frome (aka Psammosteus) limestone top member of the Silurian (Raglan) were close by but higher up the hill. A previous blog told of the lime kiln built into the limestone not far from the stream that we were exploring. Half an hour of clambering brought us to a surprising and impressive cleft with water tumbling over its lip in a double drop and a fine tufa fan encased in liverwort descending its face. So rugged the ground and obscured by trees and dense vegetation that surely few reach this spot. A much more direct route back through carpets of wild garlic, to the warmth and hospitality of Robin and Lesley’s house, rounded off a memorable morning.  Thanks to Robin and Lesley for their as always warm welcome.

Surely a highlight of the evening and a marker for years to come were the three rock sample display cabinets designed and made by member Ian Pennell (of Scar Cottage the magnificent Bromsgrove Sandstone quarry garden in the village).  Since retiring, Ian has submerged himself in a number of practical pursuits and his cabinet making talents were harnessed to produce these very fine items from Yellowwood, a hard, much sought after South African pine. A little ceremony of unveiling took place with a short speech of thanks from David and a round of applause.  Well done and thanks Ian!  A day out is set for July 11th 10am at Crown Martley–come along if you can.  The ideas is to plan a route, then go out to collect, ultimately, samples of all of the formations from the surrounding area.  Last count suggested there are over 20, so doubt the job will be done in one go.

Georgia, with her very obvious affection for the Lizard in South Western Cornwall, so fond is she that she had written a song that she performed for us accompanied on her guitar–yet another talent of this talented lady! Georgia knows the Lizard as well as anyone, particularly the exceptionally varied and in places very rare geology, a slice through a section of ocean crust, including the upper level of the mantle, thrust onto continental crust. One immediately realises that a field trip-would have to be at least for a weekend–and beckons strongly, a fascinating area with Georgia as number 1 choice for leader and guide.

Busk Coppice and Quarry Hill

St Mary’s, Stanford with Orleton, looking South

Under the Spreading Chestnut tree

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.

Sandstone from West of St Mary’s

Sandstone from West of St Mary’s

 

 

 

 

 

 

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?

Lime Kiln in Busk Coppice

Lime Kiln Busk Coppice

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

Conical Kiln in the Undergrowth

 

Sketch of Lime Kiln, Busk Coppice

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.

Valley Geological Map from BGS, click to enlarge

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?

Conglomerate, both ruddy and grey with bedrock behind

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.

Conglomerate

Top of Quarry Hill, Mike on Access Trackway

Teme Valley around Stanford

More Quarry Hunting

hmm, our quarry was a quarry, a quarry or quarries that supplied stone (St Maughans) to local buildings, for example St Mary’s, Stanford with Orleton.

Another magnificent perfect blue sky winter day, ice in the shade, crystal views in all directions, what better place to be than the Teme Valley near Stanford even if for much of the time we were slipping through mud and tripping over brambles.  Having phoned first, Ian and I called and made our acquaintance with Mr Churchill who tenants Fall Farm.  He kindly allowed us on land alongside the Bromyard Road where Mr Lane had told us there would be a stone quarry, and indeed a crag is marked on the OS map.  Mr C told us of a lime kiln near the quarry and a place where years ago a farm worker used to live, saying he was surprised that the kiln was not listed.

After a bit of a false start on a trail that dead ended in impenetrable woodland we found good, if muddy tracks and around the corner there was the quarry.

Ian, for scale, on the quarry face

Now well taken back into nature so very little rock was showing it was nevertheless clear enough to access the face.  On the day, Ian was the more agile so scrambled up the slope, found some rock and we brought back a few samples. After scrubbing up and a full dishwasher cycle see below for a picture of micaceous sandstone we believe to be St Maughans, a Devonian Formation, used in many local buildings. Realising that St M

St Maughans from the Quarry

along this part of the valley, sits atop Bishops Fromelimestone (formerly Psammosteus), Ian descended into the steep Vee side dingle below the quarry and lo and behold with a bit of digging about, found the typical noduley limestone that typifies this calcrete or fossilised soil, picture below.

We did not locate the lime kiln, this requires another visit, but one can only assume that it was placed there to take advantage of the calcrete,

St Mary’s Church

there being to our knowledge no other sources of lime this side of the valley.  We need to check but it could be that the main quarry was the source of stone for St Mary’s Church that sits so proudly on a promontory over the valley above Stanford Court, built there when a large lake was required in front of the Court.

Washed and dried specimens (click to enlarge):

Bishops Frome and St Maughans

BF and St M 2