Why I love Geology III

Tyntesfield

‘Please pass the kippers, dear,’ requested Mister Gibbs,’ I feel I shall need the energy today so I intend to have a good breakfast.’ 

‘Good idea my husband, we don’t want you expiring during the day from a lack of sustenance do we? Why especially today though?’ enquired Mistress Gibbs.

We are in dire need of extra supplies of limestone both for road stone to repair the drives around the estate and also to feed the voracious lime kilns that are busy producing fertiliser for the Home Farm and mortar to complete the sawmill we are building in our old limestone quarry. ‘ he mansplained.

‘Why cannot you just put more men to work on that quarry?

‘We are quite deep in the hillside now and any further production of limestone will require much work just to dig down to reach the stink stone and we have no need of the Keuper Marl above it.’ he patiently explained to his wife.

‘I have had a couple of good men these last few weeks searching for a good site for a new quarry; one that will need less preparation to make it fit for full production. We will start quarrying with a full gang this morning and I intend to be there for most of the morning to ensure that my wishes are carried out exactly. We also have another load of coal coming in from Mr Lucas’ mine in Nailsea to fuel the lime kiln, so you can see why I have need of much sustenance this morning – I need feeding just as much as the lime kiln. Tee Hee,’ he laughed at his little joke. ‘Perhaps one more plate of devilled kidneys and a spoon or two of kedgeree from this famous sideboard.  That should sustain me until dinner.’

‘Yes, dear,’ acquiesced his wife, not really sure what he was on about, ‘you know best, dear.’

‘Indeed,’ agreed Mr Gibbs – the first Lord Wraxall.

*****

‘Where do you want to start your Lordship?’ asked Samual Kellaway, the recently promoted quarry Supervisor.

‘I think it is best to start on this corner. I can see that you have stripped the trees and the understory from the area of the planned quarry, that’s good work,’ said George Abraham Gibbs. ‘We can strip off the top soil and cart it to the Home Farm to improve some of the shallow soil areas. Then of course we can set about quarrying off the Keuper Marl overburden. This we will then cart to the saw mill as I am thinking of building an extension to the sawmill and can use the Keuper for rough building work. I expect to be able to start work on the underlying limestone tomorrow – that is, if your survey is correct of course.’

‘Yessir, your lordship,’ said Sam, sweating. He knew his promotion was on the line.

‘If you need me, I shall be up at the lime kiln for the rest of the morning and back to the house this afternoon.’. I’ll be here again tomorrow morning to see how you are getting on.’ He shouted over his shoulder as he cantered off up the track at the side of the wood.

*****

‘What are you doing today George, are you playing with your new quarry?’

‘Yes, I shall be working on the new quarry – not playing, Ursula, we need the limestone it contains for the estate.’

‘Of course dear, you had better be going then. Have you had your fill of breakfast?’

‘Yes thank you my dear, my belly is full of devilled kidneys.’

‘George, don’t be so vulgar!’

*****

His groom had ridden up from the stables with his horse. George hoisted himself up into the saddle and then rode up past the chaplain’s house and Home Farm to the site for the new quarry on the edge of the Sidelands Wood.

Sam had all his quarry men working since six that morning so the Keuper Marl had been scraped off and carted away to the sawmill quarry. The freshly exposed limestone,”stinkstone’ as the quarrymen called it because of the sulphurous smell it gave off when crushed, was shining freshly in the sunlight.

‘Right then Mr Kellaway, let’s start with the first drill and see what we’ve got shall we?’

‘Yes, your lordship,’ agreed Sam as he signalled to two of his best men to start drilling. One man held the steel drill in a pair of tongs and twisted it 90 degrees between each hammer blow.and the other hit it regularly with a sledge. It was soon some six foot deep in the rock and the ‘hammer man’  was able to descend from his wooden staging. The drill was pulled from the hole and the dust was blown out manually with a thin tube. A cylinder of black powder was inserted in the hole, then an electrical detonator followed by more black powder which was carefully tamped by a wooden pole. The detonator cable was run back some distance from the hole and then connected to the hand generator. Sam turned off the safety switch and then asked if Lord Wraxall would do the honours of setting off the first blast. George stepped down from his horse as Sam blew his blasting whistle, gave three minutes for all to get clear and then Lord Wraxall bore down on the generator handle. There was a mighty explosion, which unsettled George’s horse and then the cliff of limestone surged towards them. All had a cup of tea from the urn accompanied by many a hand rolled cigarette, while they waited for the dust to settle. They then started shovelling the limestone into the waiting carts which were pulled up to the lime kiln by  the working horses.

Lord Wraxall inspected the limestone face with Sam and they both agreed that the limestone was of good quality and would be equally good for road stone and feed for the limekiln. This was the start of a long life for the Sidelands Quarry. 

*****

We three arranged to meet at 1030 at the NW corner of the car park. It was 1st October 2018, a lovely sunny Autumn day.

We headed for the Sidelands Quarry – now long disused as a quarry but with a new life as a location for a 4G telephone mast. Sidling through the gaps between the mast and the cabinets of ground control gear, we entered an enchanted area. The old quarry walls rose on each side, trees had made their homes in and around the quarry, making it a dark, damp place with the quarry floor colonised by ferns and brambles. Ivy dangled thickly from an overhanging tree.

Speaking as a geologist, the wonderful thing about quarries is that they expose the underlying rocks that you may otherwise never get to see. This quarry is a case in point. There are two rocks exposed along the working faces. One is what the quarrymen were looking for, which is Clifton Down Limestone. Above this is the Mercia Mudstone Marginal Facies. The wonderful thing here is that the junction, or unconformity, can be clearly seen between the two rocks. The CDL is about 340 million years old – mya – from the warm, tropical Carboniferous sea, while the MMMF is around 150 mya. from the Triassic. This formed from the eroded products from the adjacent highlands as sharp edged clasts can be seen within it. This means that you can span 190 million years with one hand. I find that awe inspiring. Also in this quarry can be seen a myriad of dog tooth spar – crystals of calcite – Calcium Carbonate. Some are in sheets on a fault surface and some are in huge vugs – or caves, lined with the same crystals.

After looking at all these wonders, we then wandered off, through the check in control and then we were free to poddle along, enjoying the landscape and weather as we discussed the Chaplain’s house and then we spotted the moon in the clear blue sky – why hadn’t it gone to bed?  We arrived at the saw mill quarry. There was some discussion about the building stones used to build the mill in the quarry and, of course, the old style mortar that had recently been used to repoint the walls of Triassic MMG. This had the charcoal bits in it that showed the Calcium Oxide had been produced in a lime kiln. It was then time to inspect one of the Oolitic Limestone window surrounds – to see the multitude of Ooids from which it was composed and the complex cross bedding.

After checking and identifying all the building stones in the mill, we wandered off down the path leading to the formal gardens, noticing en route the phenomenal lumps of calcite crystals that were heavily disguised by the moss growing over them. I wonder how many National Trust people know that these wonders are there? And, if so, why they don’t clean up one of the lumps of crystal and put it on display with a spot light on it, in the check  – in area?

We left the crystal path behind and ventured down the main front steps to the flower gardens where a team of gardeners were hard at work. After admiring a beautiful specimen of a monkey puzzle tree Araucaria araucana. Then it was through the ha ha retaining wall and along a paved path to the walled gardens.

After all this walking, talking and looking at the wonderful landscape, we felt the need for some refreshment. Luckily there was a cafe to hand so we settled down with a coffee each and tried to process all we had seen. The coffee was hot and strong so we managed to get a lot of talking done but no note taking or writing, which was our original intention. We realised that we would have to retain our findings and impressions of this wonderful place until we got back to our garrets to get them down on electronic paper.

Now it was time to retrace our steps but we decided to take the curved road, past the huge sequoias along the way. From here we could just see the stables, through the trees. We passed the main entrance to the house, walked past the chapel then found ourselves back at the top of the crystal path. We followed the road as it curved around the gully down to rose garden – admiring the collection of water-worn limestone rocks by the side of the road. The conclusion was that they were formed in the phreatic rather than vadose zone because of the almost complete roundness of the wear. but this is open to argument and proof.

For some reason I was quite hungry and felt a desire to eat some devilled kidneys and, perhaps some kedgeree. Unfortunately there was none on the menu at the cow shed restaurant. Very strange as I had not eaten devilled kidneys for about 43 years ago when I left the Royal Navy and even longer since I had eaten kedgeree.

We passed through the gauntlet of souvenir shops in the Home Farm buildings and then we were free to return to our respective transports to return home and reflect on a wonderful, inspiring morning. Shame about the lack of proper breakfast food…

With thanks to the National Trust.

©  Richard Kefford Eorðdraca 2018

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