Monday, 17 October 2016

Geology, architecture and fantasy


A grotto fountain at the Georgian house which is home to the American Museum.

That cascade of rock which hovers above the now empty bowl of the fountain is Tufa - the same stuff as I have just imported 2 tons of from Canada, via Ohio. The trouble is we are not allowed to dig our own up any longer, despite the fact that it replaces itself every few years.

Oh well, I suppose it makes sense. Everyone would want their own little Tufa grotto here in England if dealers were allowed to retail it. The stuff I got is to replace the missing parts of an 18th century structure - probably stolen by 20th century gardeners...

The main structure of the arch is made from stuff called 'Grot Stone', and this was dug up about 3 miles away on the other side of the valley, in a little wooded hamlet called Conkwell, where I once lived in a picturesque cottage next door to the last Governor of Hong Kong. Shawn lived about a mile or two from here when she first arrived in Bath.

This stone (it is a true stone, unlike Tufa) is characteristically riddled with worm-like holes of varying diameter, and the artificial architectural masonry representation of it is called 'Vermiculated' stonework - more references to worms. It is invariably used for the lower courses of grand buildings, such as the outside of the Roman Baths here.

Nobody is too sure about how these tunnel holes were formed - some say it was marine-life burrows, and others say it was the action of water-courses. It is also a rare commodity these days, second-hand stuff selling for around £1000 a ton, and it only takes a cubic yard to make a ton.

When you saw up Tufa - it is very soft and easiy sawn - it gives off a highly pungent and sulphurous odour which is quite unpleasant. This is due to all the organic matter which has left fresh gas trapped within it, released by the saw-cuts.

The same is true of some real stones which are 140 million years older than Tufa, and I like the theory that this gas is the trapped farts of dinosaurs when wallowing in the mud which formed the rock. Why not? There is such a thing as 'copralite' - look it up.

There is one particular type of Bath Stone which has smallish lumps of ferrous metal embedded in it which shine brightly when the saw cuts through the rusty exterior.

Scientists tell you that this metal is formed by the minerals grouping together over the millions of years, resulting in concentrations of metals and crystals, but I prefer the theory of one particular stonemason I knew once.

He assured me that these lumps of iron are the remains of alien space ships which crashed into the primordial mud of earth's watery surface during the era of the dinosaurs.

As I say, life is so much more interesting when you are prepared to believe in anything.


34 comments:

  1. There is very similar looking stone here which comes from the river Lot. People have big lumps of it in their gardens for 'decoration'.

    ReplyDelete
    Replies
    1. I think that holey stone crops up everywhere where conditions were right.

      Delete
  2. You're an old romantic at heart Tom ..... you always have such lovely ideas about every subject you talk about !
    I'm sure that I've come across bits of stone like that when digging in the garden but it's probably just hardcore !!!
    Don't stop believing !! XXXX

    ReplyDelete
  3. That is why i believe in any thing, not only in fairies.

    ReplyDelete
    Replies
    1. I think the worse things can get, the more we need to believe.

      Delete
  4. Have seen "grot stone" before, but didn't know what it was called. As my (adult) granddaughter says.. "every day is a school day"
    Gill(ian)

    ReplyDelete
    Replies
    1. That is just an 18th century nick-name for it, I think.

      Delete
  5. Dinosaur farts...there's a concept that I never once thought of before today. Thanks Tom! Haha!

    ReplyDelete
  6. 'sometimes I've believed six impossible things before breakfast'

    ReplyDelete
    Replies
    1. And that's after a night of dreaming about them - it's easier before breakfast.

      Delete
  7. Fascinating stuff, Tom. Not least your narrative. I imagine there to be little room for error when working with such precious, and unforgiving, materials.

    U

    ReplyDelete
    Replies
    1. It is not that unforgiving or precious - unlike white marble. When they split the largest diamond in the world, it took one blow of under one second, but they spent three years planning that blow.

      Delete
  8. Our Verona Red Marble is of Jurassic period; now I will always remember dinosaurs' farts!
    Greetings Maria x

    ReplyDelete
    Replies
    1. Siena marble is now virtually unobtainable in its best, antique form. When you go to Siena, whole flights of steps, pavements and buildings are made from it - material which is now worth about £500 per cubic foot.

      Delete
  9. Thank you, Tom. I thoroughly enjoyed this post and am glad to have had the opportunity to read it. My day in this life has been made much more interesting.

    ReplyDelete
  10. Well, the climate warming lot say that it's caused by cows farting carbon monoxide, so it's must be logical that dinosaurs farts (presumably being much bigger and possibly louder than a cow's) this could have possibly caused the end of the last ice age and facilitated the extinction of them all.. So that puts paid to the asteroid theory, doesn't it? Don't forget this theory was a result of Tom's remarks about farts. So when I publish my paper I'll be sure to give him the appropriate recognition. T1he Nobel Prize beckons

    ReplyDelete
    Replies
    1. You make me proud to have been the spark.

      Delete
  11. Some folk believe anything. Did the little dinosaurs produce smaller farts than those great big things? Now there is a question to tax the mind.

    ReplyDelete
    Replies
    1. I would have thought this is the case, Weave, but it is easily tested by attaching sensors to a chicken and a cow.

      Delete
  12. Grot Stone looks a whole lot like sandstone, quarried for miles around my home. Except the sandstone appears to have no holes for dragon farts. Is Grot Stone sedimentary, too? I can't find much about it, past John of Grot.

    ReplyDelete
    Replies
    1. Grot stone (a local nick-name, I think) is inavrariably a limestone. We have all sorts of other stones, but without holes.

      Delete
  13. Dragons don't fart, and I know that for a fact. But I would avoid their breath if I were you.

    ReplyDelete
  14. Am I the only one who googled 'copralite' after you mentioned it? Now I will have to get those images out of my head. One image showed that they even make dangly earrings out of it. Imagine!!

    ReplyDelete
    Replies
    1. Better than making earings out of the unfossilised variety.

      Delete
  15. Replies
    1. No. She may have moved into deep tundra which has no signal. I never expected to hear as much from her as we did, even in the big cities.

      Delete
  16. There is something about stone that is so special. Warmer than metal, stronger than wood which is why I am most drawn to stone cottages. No explanation though for why I live in a round metal building.Anyway, I always learn something new from your posts Tom. Thanks for that

    ReplyDelete
    Replies
    1. It isn't really stronger than wood, due to its inflexibility. Traditionally, the Japanese built with wood to withstand earthquakes. I have spent most of my life in stone buildings, and it is a real treat to spend the night in an old wooden one.

      Delete
  17. Our inherited fish pond had huge lumps of tufa in it-for the fish to play around and through. Plus lots of smaller, but heavy lumps around the garden. Since the fish have been given away, I put the lumps in the ex-pond and gravel and soil. We now have a sort of rockery with bulbs and pansies planted so far with the tufa. Cats have come but no dinos.

    ReplyDelete
    Replies
    1. You can still buy small lumps for fishtanks, and the man I bought my 2 tons from a man who specialises in selling it as a growing medium for plants in rockeries. It has holes in which the roots can take hold, and is also rich in nutrients. The trouble with cat-shit is it takes too long to fossilise, and they love sand-pits.

      Delete