I visited Slaley Sough for the first time last night and was quite suprised at the extent of the workings.

I find it intriguing that such extensive workings exist where it appears negligable amounts of ore exist. I'm left pondering the following questions:-

Why would you create such passages if you were only prospecting for ore?
Why wasn't the entrance level enlarged to the size of the other passages? This would surely make waste removal easier.
Why is the entrance so small and difficult to get to? It seems an awkward way to get everything into and out of the mine (rails, wagons etc)
Given the evidence of some sort of rails in the larger level, why isn't there evidence of any in the entrance level?

I've heard that the internal shafts/raises are blind. Markpot tells me he's climbed one, and I've read that Thunder Shaft is blind, but I wonder if all the raises have been fully explored.

If anyone has any information that they can add it would be appreciated. In my mind, it appears that there's more to Slaley than meets the eye.

Pm me your email mad I'll send you some info I dug out last night.

I've just read the the section of PDMHS vol 4 part 6 on Slaley. I wish I'd read that before visiting as it would have made for a better understanding of the place.

As far as I'm aware, the long drivage and Thunder Shaft were funded by investors in the latter half of the 19th century, who going by the amount of ore in the vein had more money than sense. I've never understood why the entrance level wasn't enlarged at this time, given how awkward it is to get in and out, unless there's something in the geology above that they didn't like and wanted to keep a reliable roof.

It's interesting that the PDMHS articles suggests miners got into the mine via the second raise. That might be worth climbing to see where it ends up.

There is a good section on slaley sough in Jim's book drainage and mines Elton to the via gellia,documenting the history of the mine along with a good description.i have read documents refering to the  old and substantial working in the fields above refered to as thunder mine? It has a very small adit and plenty of shafts.interesting reference to some test shafts along the fence lin sbove the entrance.I am of the same opinion as madness,as I have only climbed the first raise/stopping and t'owdans man's shaft near the first T junction,the second  raise must be worth a poke.the stuck climbing wire suggests investigation  at some point and it's in the rough location of plenty going of above.

Madness,if your interested i have scanned the section from Jim's book ,its an intersting read,map included.pm with email  if you want it.i also have some doc's of later exploration with maps.

It was the speculating mania following the passing of the Limitied Liability Acts in the mid-1850s that made it easy for local tradesmen to take small shares in mining ventures - simply a form of gambling. Such ventures at Matlock tended to be fraudulent, particularly those at Haslam Pipe, whereas those at Bonsall were blindly optimistic.

We covered some aspects of Slaley Sough back in 2012 under the heading "Thunder Shaft":
http://ukcaving.com/board/index.php?topic=14043.0

My own postings at that time were:
The reference to the article about this level (properly called Bonsall Leys No. 2 Level) is:
Flindall, R.B., and Hayes, A.J., 1971. The Adit Workings on the North Side of the Via Gellia. P.D.M.H.S. Bull. Vol. 4 Pt.6 pp429-450.
I wrote that article and have recently been compiling a report on the history of mining in that area.

The 150 feet deep turn (called by the spar miner Cyril Maddocks in the 1950s the Thunder Shaft) was on Flixen Rake but it was always blind (even when it was first sunk) and there is nothing to be discovered really in the level at all. I wrongly stated in the article that the raises no doubt went in stages up through the toadstone to the surface but they would be blocked by collapse. In fact, the raises lead only into short trial levels just below the toadstone.

The only air flow in this long level seems to be that originating from a three inch wide open rift in the right wall of the level about 15 feet before the final forefield. The sound of falling water can be heard faintly in the distance (or at least it could in the 1970s), which is surprising because the overlying toadstone keeps all that strata very dry. There must be some sort of fault to allow the water to penetrate. There is a moderate airflow into the rift in summer. I cannot understand why the miners did not investigate this as it could lead to some sort of vein or cave. This point is about 250 feet below the surface of Bonsall Leys.
I only noticed the noise of the water because I was by myself on one visit. It may only be a slight trickle of water. I did look in the roadside entrance in the Via Gellia (Bonsall Leys No. 1 Level) to judge if that could be the exit point for the spring but could not detect any airflow associated with the water. I am not an expert on hydrogeology.
There may have been an old shaft at that point through the toadstone on Parsons Rake (the vein followed in the last part of Bonsall Leys No. 2 Level), which may have let the water through the toadstone.
I should have made it clear in my earlier posting that there were old (18th century) shafts from the surface intersected by the No. 2 Level at the end of the entrance crosscut and also near the Thunder Shaft but they are so thoroughly blocked somewhere that there is hardly any airflow from them. There were also several raises made from No. 2 Level to test the veins just below the toadstone but none amounts to very much.

Thanks for the info Historytrog

The entrance by the roadside is quite interesting as there appears to be minimal flow of water. However the culvert that rums from the steam and under the road towards it can have quite a significant flow at the same time.

History Trog, quite a few years back I was up the end there by myself and the sound of the water through the wall seemed so loud at the time, I was attributing it to a pump. It was only your references to it in that 2012 discussion, that shed a bit more light on it. I do wonder about the size of the natural possibly hiding in that vicinity.

The water noise through the crack isn't always there, though I've heard it on several occasions on my last visit (December 2016) there was draught but no sound at all. That may have changed afer the last few days though!

Can anyone suggest why the later passage is so much larger than the entrance level? Would that be due to changes in mining methods?

Also, with regard to the mention of the possibility of some natural cave existing, would I be correct in assuming that natural would be more likely to develop above the toadstone layer?

Also, is anyone aware if any of the shafts above on Bonsall Leys been descended? If so, are they documented anywhere?

Probably more likely to develop below the toadstone, if water is able to get through somewhere - additional acidity is produced by percolation through the toadstone (mostly pyrite-based I think), enabling greater-sized cavities to be produced. The shafts in the lower half of Nettle are a good example, and some of the Peak-Speedwell avens.

I seem to remember Jim Rieuwerts mentioning that some of the Bonsall shafts were descended in the 50s, but that most were very shallow, as the useful mineralisation was mostly close to surface - and they didn't write up as much in those days...

As has been stated already Slaley is pretty dry due to the overlying toadstone layer. However there are places where the water is getting through. I've not heard the water in the rift just before the end forefield (making too much noise) but perhaps that is a likely place that natural has developed below the toadstone as Historytrog has already mentioned. It's also wet around the second raise with water dripping down the raise. To me this suggests that the second raise might penetrate the toadstone.

Regarding Bonsall Leys, why are all the shafts shallow? How did the miners establish that the useful minerals/ore was not that far below the surface? I'd be surprised if there isn't at least one deep shaft at Bonsall Leys.

There is a large shaft mound on Bonsall Leys with a stone buddle built into the side. Since the nearest surface water is some way down the valley side to the south at Dunsley Springs the water must have been pumped up the shaft (at least that's my theory). Did the workings intercept the underground source of the Dunsley Springs water running above the level of the Matlock Lower Lava?

I've just read the Historic England web page on the Bonsall Leys site (Scheduled Ancient Monument), and that suggests that water was mechanically raised from a nearby shaft to feed buddles. If that is the case, that shaft may be worth exploring. There's a PDMHS article on the Fools Venture Mine that I need to read. That may shed more light on the subject.

Madness said:

Can anyone suggest why the later passage is so much larger than the entrance level? Would that be due to changes in mining methods?

Click to expand...

I'm not familiar with Slaley Sough but there are various examples elsewhere of adits whose further reaches are of larger cross section than their outer portions, this reflecting evolving mining techniques and standards over a period of many decades or longer time periods. Sometimes the small cross section outer portions of an adit might be stripped to match the more commodious inner and later cross sections but such approaches were far from consistently applied.

The PDMHS article on the Fool's Venture Mine at Bonsall Leys suggests that a shaft went down to Slaley Sough from there. This seems to be unsubstantiated.

The Fools Venture work was surface only IIRC, so any reports of shafts going down to sough were likely anecdotal or speculative. There is a shaft I suspect may have been used for raising water, possibly while trying veins under the toadstone but it's on the Great Rake and not that near the course of Slaley, it also has a beehive cap so any descent would require scheduled monument consent from Historic England to remove and rebuild it!

The veins below the toadstone are largely barren, as you see with Flixen Rake in Slaley and Great Rake in Dunsley, which is why most of the working is from shallow surface shafts. Both of these adits were trials to see what the veins were like at depth, but at least some of the shafts on Bonsall Lees must have been deep trials too, given the use of horse gins.