Alderley Edge new discovery?

[Badlad]

Cavers find pristine mineshaft frozen in time for 200 years

Experts describe cobalt mine at Alderley Edge as ‘time capsule’ thanks to lack of oxygen

www.theguardian.com

 

[Rob]

Original release here, including a pretty cool 3D tour of the place

Press release | Media

Ther National Trust has announced a new discovery at Alderley Edge, Cheshire offers a glimpse into mine production in the Napoleonic Wars. See the full story.

www.nationaltrust.org.uk

 

[Bob Mehew]

Is this the logical end point for conservation concerns?

 

[wellyjen]

Is this the logical end point for conservation concerns?

The 3D model running on a set of VR goggles; have some one throw buckets of cold water over you and repeatedly hit your knee caps with a cricket bat. Replicates cave/mine exploration nicely from the discomfort of your own home.

 

[Cantclimbtom]

Amazing survey (and digging!)

Maybe I'm thinking on similar lines to Bob? If the preservation is so good due to low oxygen -- to preserve it longer, flushing the mine with nitrogen and resealing it would be the logical step, but that stops people from enjoying it in the flesh, give or take the "4D" experience (the silly name for VR + buckets of water etc).
Rekindles the old debates of conservation versus preservation and artefacts in museum or left in situ. Not sure there was ever anything close to consensus on these matters

 

[Tangent_tracker]

We will be sealing the entrance up but certainly not to the extent you can flush with a new atmosphere.... The sandstone along with faults are too porus for that, it also connects with Cobalt mine (it is really the same mine) in two places, possibly 3 (flooded). As you say, we want to be able to visit occasionally, more than likely for historians/geologists, it certainly won't be generally open nor will it be on the usual set of keys so permission must be sought.
I think we will be getting advice from the museum as to how best to preserve the remaining items. Perhaps there is an argument for them to go to Manchester Museum if they can do so without damage?

The late 18thC bowl was found by Ed and was carefully and deliberately buried in a wall and is, for me one of the highlights due to it being such an unusual item to find underground. Hopefully, Manchester Uni will take samples as we suspect the glaze will be the Manganese extracted from this very mine, and must clearly be a gift in return for minerals extracted...

The intact windless is a first for Alderley too and again gives insights as to how they winched materials up and down.

All in all a cracking find. There will be a better version of the video released, they only surveyed about 3 weeks ago! They are also bringing a sub to explore the flooded workings and 3d scanning the artifacts at a higher resolution.

If anyone wants to know more they can contact Ed or Nigel through the club.

 

[Cantclimbtom]

The national trust article doesn't contain the word "oxygen" but the Guardian one does in 3 places stating the preservation is due to "lack of oxygen". Was low oxygen significant?

 

[Tangent_tracker]

The national trust article doesn't contain the word "oxygen" but the Guardian one does in 3 places stating the preservation is due to "lack of oxygen". Was low oxygen significant?

I think we probably have to assume so yes, given the condition of the rope and timber in general, and the fact that when we broke through the air was particularly bad. Sadly we did not have a meter on the day of the breakthrough as I am sure it would have been interesting to get a measurement!

 

[pwhole]

It's an interesting one, whether to leave or remove. We ended up giving the NT most of the 'portable' artifacts we found in Longcliffe, after thorough documentation first, They were concerned that with access being available, many of them might not survive constant attention, or worse, be stolen. However, I recently found a piece of medieval pottery in a stream in some woods near mine, and brought it home to photograph it, and notify the local archaeological service. The guy I spoke to essentially (though politely) told me off for not leaving it where it was, on the grounds that was it now 'out of context'. The amount of house-bricks and other recent detritus in the stream suggested it was already way out of context, and I'd already made that judgement before I brought it home. So it sits on my shelf at present - he suggested I take it to the local museum, but said as they may have quite a bit of this already, it would probably end up in a box and be forgotten. The endless dilemma of what to do.

 

[Bob Mehew]

My thinking behind my comment of "Is this the logical end point for conservation concerns?" was more about high quality recording of the passage found, rather than the artefacts. The fly through provides one handle on giving people an experience of what a place looks like in addition to taking photos. (Though I like the idea of having a surround environment experience with added "throw buckets of cold water over you and repeatedly hit your knee caps".) Should we be encouraging such developments?

 

[pwhole]

I think where a site is especially sensitive, or particularly difficult to reach for most cavers, and warrants the massive effort, then yes, I think it's a great idea, not least as it enables completely non-cavers to get a pretty good idea of what it looks like without having to experience what it feels like - they may then decide it might be worth trying it for real. Plus the inevitable advances in technology and technique that always result from persisting with very difficult subjects usually offsets the misery of doing the hard work of recording. The James Webb Telescope images released today are a good example of very pleasant output and hardcore science being obviously connected for the public.

 

[wellyjen]

I think we probably have to assume so yes, given the condition of the rope and timber in general, and the fact that when we broke through the air was particularly bad. Sadly we did not have a meter on the day of the breakthrough as I am sure it would have been interesting to get a measurement!

Presumably, there is some chemistry, or possibly biology going on to deplete the O2 in the air in the partially sealed passages. Any ideas what it may be? Are there any plans to sample the atmosphere over time remotely? A pipe through the cap and down the shaft perhaps?

 

[mikem]

I don't know if it's the case here, but cobalt is often found with other elements such as sulphur, that are very reactive with oxygen (but normally more oxygen would leak into the system to replace that lost)

 

[Tangent_tracker]

My thinking behind my comment of "Is this the logical end point for conservation concerns?" was more about high quality recording of the passage found, rather than the artefacts. The fly through provides one handle on giving people an experience of what a place looks like in addition to taking photos. (Though I like the idea of having a surround environment experience with added "throw buckets of cold water over you and repeatedly hit your knee caps".) Should we be encouraging such developments?

The video flythrough you see is only a rough copy, they will further process to separate point cloud and images from what I understand, and hopefully remove some of the artifacts too. The end result should be very high quality and provide genuinely useful data for those who want to know more. The scanner had a resolution of up to 0.1mm at close range, although not sure if they went that high in this case.

 

[Tangent_tracker]

I don't know if it's the case here, but cobalt is often found with other elements such as sulphur, that are very reactive with oxygen (but normally more oxygen would leak into the system to replace that lost)

There is actually very little Cobalt in these mines, perhaps 1% at most. Manganese runs at about 8% I believe. Saying that there were some very black lumps of Wad that we have not seen in Cobalt mine which we need to send to MMU for analysis. There will be other elements within the wad I am sure some of the timbers will have contributed too.

 

[Tangent_tracker]

It's an interesting one, whether to leave or remove. We ended up giving the NT most of the 'portable' artifacts we found in Longcliffe, after thorough documentation first, They were concerned that with access being available, many of them might not survive constant attention, or worse, be stolen. However, I recently found a piece of medieval pottery in a stream in some woods near mine, and brought it home to photograph it, and notify the local archaeological service. The guy I spoke to essentially (though politely) told me off for not leaving it where it was, on the grounds that was it now 'out of context'. The amount of house-bricks and other recent detritus in the stream suggested it was already way out of context, and I'd already made that judgement before I brought it home. So it sits on my shelf at present - he suggested I take it to the local museum, but said as they may have quite a bit of this already, it would probably end up in a box and be forgotten. The endless dilemma of what to do.

It's a bit silly really, it's not like you couldn't head back there and place it back for them to see! I can understand in some instances though!

 

[Bob Mehew]

I suspect that although archaeologists are way behind crime scene investigators, they can do some things if the scene has not been corrupted. Metal detectorists must be a real pain. A stream littered with recent detritus does seem likely to have been corrupted.

 

[AR]

Speaking as someone with archaeological training, the key thing is context - how does the object relate to where it was found and what information can be derived from that. In the case of a bit of pottery found in a stream deposit, I'd say it's pretty unlikely to be in its original place of loss/deposition and so it really doesn't matter. If a professional archaeologist does start getting on their high horse like Phil's described, the magic words are "unstratified find"...

Going back to the new find at Alderley, if it's pretty dry in those workings then that will also be a factor in the good preservation of timber - a combination of not much air flow and not much moisture can be quite good for slowing decay right down.

 

[pwhole]

As we've seen in Odin, age doesn't necessarily indicate decay/weakness in timber. Even in the shaley areas it holds up really well - we've used several for deviations, as pointed out on another thread. I suspect atmospheric moisture (or lack of) is the key, and possibly constituent gas variations in fairly enclosed systems - many of the gold/silver mines in the US look almost brand-new underground when it comes to the timber.

 

[Tangent_tracker]

As we've seen in Odin, age doesn't necessarily indicate decay/weakness in timber. Even in the shaley areas it holds up really well - we've used several for deviations, as pointed out on another thread. I suspect atmospheric moisture (or lack of) is the key, and possibly constituent gas variations in fairly enclosed systems - many of the gold/silver mines in the US look almost brand-new underground when it comes to the timber.

Very true!