The Mine Shafts Project. Hydrology.

[The Old Ruminator]

Thanks Andy you are far more adept at this sort of thing than I am. I do what I do best in keeping a record and trying to understand the things that I see. Long term we dont yet know.. Certainly when free of the licence constaints we can be more site specific and look at the rich social history that has been recorded. But then there may not be access as its a huge responsibility in such a vertical site and I for one dont want long term responsibility for the engineering. Our small site is important as it shows 18th C. mining techniques and associated structures. It has social history well documented describing the workings and the constant worry regarding investors. A forced closure in 1801 resulted in a reopening in 1817 with new investors brought in by the lure of wealth at sub adit level working. All based on false premises and a poor understanding of the geological processes in play. The geology itself is laid bare and tells a story of its own. Final closure in 1821 saw the workings mothballed awaiting the new investors that never came. Maybe a visit by Coleridge who certainly knew the miners and their work.
"Through caverns measureless to man
Down to a sunless sea."
Yes a nice thought and you never know ---

 

[The Old Ruminator]

Sadly this account lacks the structure that I would have liked inasmuch that I never intended to get this far in the first place. So we have bounced about a bit though things are largely chronological from around page five. So maybe as Andy has made a supporting comment a bit about the geology.
We have steeply bedded Devonian Limestone part of a denuded anticline bordered by associated slates ( killis ). The slates were easily worked when adjacent to the limestone but produced no copper. That mostly came as a fluvial substance rather than an ore. At times even as a thick paste. Deposited within the birite lode by rising thermal waters. To me the extraction rate of copper looks miniscule compared to the extraction rate of material required to get it. The limestone in places has been buried by thick lenses of Triassic Sandstone a lot of which can still be seen in the workings and structures. The Triassic rocks may well have formed an impermeable cap trapping the rising waters and forcing them down again the saturation zone thus contained. Subariel erosion has degraded the Triassic Sandstone in places so that sand can be extracted.

Current water levels in main shaft in metres.



Barite / limestone horizon as seen at Cannington.



Small crystal lined vugh in the birite lode from discovered chamber.



Fluvial copper matrix.



Macro malachite in the barite lode.

 

[The Old Ruminator]

Macro malachite in split lode barite.



Sample from the dig. Ochre ???



The " Heavy White Spar " as defined by the miners.



With miniscule crystal vugh centre.



Macro malachite in birite from Cannington.



As an antithisis sample from Vurley showing epigenic solution derived from constant chemically aggressive drip from water that has passed though seven metres of capping loess.



Discussed in Chelsea Journal Vol 65 Nos 1-3 March 2023 " Thoughts on Two Digs Epigenic and Hypogenic " Citing Vurley as Epigenic but far from the Mendip norm. Neither Vurley nor the mine chambers exhibit much in the way of calcite.

 

[The Old Ruminator]

I wish the forum would give the authors more time to correct text in the uploads. That and the fact that single incorrect image codes cant be deleted without deleting the whole post. Its hard enough maintaining concentration with image editing and uploading without checking the spelling and text code errors. Barite/Birite. Oh well you know what I mean. Also I cant retrospectively go back and add images or text to previous posts in the thread as things come to mind. What goes in has to stay uncorrected. My collectors forum allows me to do all of this.

 

[Andy Farrant]

After writing my last post, we received the sad news that Alexander Klimchouk passed away earlier this week. Alexander was the main exponent of hypogene speleogenesis and has done a huge amount to raise our awareness of this type of cave development. As part of his secondment to Manchester University, he was actively involved in a project with BGS and BCRA investigating the hypogene karst of the Peak District and its potential impact on geothermal energy resources.

 

[The Old Ruminator]

That is indeed sad news Andy.

Some of Alexanders papers here -

Alexander Klimchouk

Principal Research Scientist, Institute of Geological Sciences, National Academy of Sciences - Cited by 4,526 - karstology - speleology - karst hydrogeology - karst geomorphology - speleogenesis

0-scholar-google-com.brum.beds.ac.uk

 

[The Old Ruminator]

Notably " Hypogene Karst Regions and Caves of the World."

Authors
A. Klimchouk, A. N. Palmer, De Waele, A. S. J., Auler, P. (Eds.) Audra
Publication date
2017
Pages
1-910
Publisher
Springer
Description
This book illustrates the diversity of hypogene speleogenetic processes and void-conduit patterns depending on variations of the geological environments by presenting regional and cave-specific case studies. The cases include both well-known and newly recognized hypogene karst regions and caves of the world. They all focus on geological, hydrogeological, geodynamical and evolutionary contexts of hypogene speleogenesis. The last decade has witnessed the boost in recognition of the possibility, global occurrence, and practical importance of hypogene karstification (speleogenesis), ie the development of solutional porosity and permeability by upwelling flow, independent of recharge from the overlying or immediately adjacent surface. Hypogene karst has been identified and documented in many regions where it was previously overlooked or misinterpreted. The book enriches the basis for generalization and categorization of hypogene karst and thus improves our ability to adequately model hypogene karstification and predict related porosity and permeability. It is a book which benefits every researcher, student, and practitioner dealing with karst.

 

[The Old Ruminator]

Sadly a wee bit above my pay grade.

 

[The Old Ruminator]

I now think that I could add the Quantock Hills in Somerset to the list. All the little caves we have found over many years seem to conform to this model. Most are at the margin of the Devonian slate beds and the Devonian Limestone proper. Peter G. soldiers on at Cothelstone pursing the dream but for the moment I would not say " no chance ". A big chamber or complex system could lie around any narrow corner.

 

[The Old Ruminator]

Back to the dig south and down from chamber two. The Horrible Hole along the lode has been intercepted in the chamber floor. The dates show progress made in September 22.

 

[The Old Ruminator]

The project as it stands today in section. The caverns are thought to be between the main shaft and a third capped shaft 70 - 75 m away both are believed to be connected via the adit. The geology and historical record suggests this and we have eliminated all leads to the NW. We shall look for the third shaft cap in the summer. It was breached in the 1980's and recapped with sleepers and concreted. Plumbed to 90ft but never descended.

 

[The Old Ruminator]

I had a nasty fright when I was examining the lode wall supporting The Elephant collapsed. Just enough remained to stop it falling. The lode wall in the new chamber collapsed as well. Nobody was close. The side of the dug tunnel fell in part burying me and I had to be dug out.

 

[The Old Ruminator]

The dig today. Main shaft and pole traverse top. Then The Alcove, dug chamber, new open chamber and dug tunnel. Dotted line at end probe in low airspace. Hopefully that leads back to the lode and onward SE.

 

[The Old Ruminator]

Photobucket image upload 25,023.
The local boys come in for a look at the new bit.





A large boulder hampers work at the start of the tunnel dig.



As does another in the floor dig later abandoned

 

[The Old Ruminator]

Peter in the floor dig.



The lode wall right and The Elephant top.



The Alcove and pole traverse from above.



This is rare. Me doing something.



Lode wall hole in the floor dig.



Digging in the tunnel.



The Elephant showing where the lode collapsed.

 

[The Old Ruminator]

Bum I am not deleting the post for the double mistake.

Brian on the pole traverse.



Peter in the new chamber through the dug choke.



Cookie.

 

[The Old Ruminator]

Matt.



Ian.




Brian and Peter.



Mr Elephant.

 

[Cavediver]

Přátelé to co jste dokázali je doslova technické dílo ,musím si projít fotky v tifu a vam doporučuji projít tezebni a geologický archyv snad alespoň trochu pochopit lokalitu a jeji nestabilní velice staré ostění ,delali jste hydrologic rozbor vody a fluorescent ní testy kam vám to utíká jako potápěč a výkonný alpinista nerad vidim hlinik v jeskyni na řebřik lezu jenom v dahrade kolem stromu,poslední na rychlo přehodit zavěšení tažné kladky tak jak je na fotce je to na velky problémy s pozdravem Codiak

 

[The Old Ruminator]

Translated from Czech

Friends, what you have achieved is literally a technical work, I have to go through the photos in typhus and I recommend you to go through the mining and geological archive to perhaps at least understand the location and its unstable very old lining, you did a hydrological analysis of the water and fluorescent tests where do you get away with it a diver and a powerful alpinist, I don't like to see aluminum in a cave, I climb a ladder only in Dahrad around a tree, the last one is to quickly change the suspension of the traction pulley as it is in the photo, it's a big problem Regards, Codiak

Maybe Codiak is not a decrepit 76. If he was he might understand the ladders. In any case it all might get closed down next year. I am not bothered by that. We did our best to explore and record. I doubt it would ever have happened otherwise.

 

[The Old Ruminator]

BOOK EIGHT in preperation.

The TG 6 does not like zoom in caves but I gave it a go.



The wet shaft 365 m to the SE of the main shaft. Both connected by the adit. In excessive rain water flows from under the cap to pour down the shaft. In 200 years much silt and scouring has occurred resulting in the collapse of all of the timbers which now block the bottom. We dug there in dry conditions for a while. Maybe a return in Summer.



Me doing video at the end choke. Photo by phone.



The patent pipe plunger. Spoil arrived here in tubs but as it got sticky we now use bags.