Intake Dale Mine Update

Rob

Rob

Well-known member
As promised, the (mostly) up to date survey can now be downloaded from the Eldon website:

http://www.eldonpotholeclub.org.uk/homepage/club-history/surveys

Unfortunately this drawn survey was started back in 2016 with the discovery of Brexit Rift. It was therefore never intended to be added to in the way that it has, but i couldn't be bothered to redo it all at a bigger scale. I'm kind of glad as we're still not sure how big it'll get!

Just goes to show how useful the Therion ecosystem is...
 
Rob

Rob

Well-known member
Hobgoblin's Hideaway is at 205m. Downstream sump 2 in Bagshawe is at 183m, and 920m away horizontally (although the end of Sump 5 is a good 150m closer)...

The exciting bit is we know the whole upstream of IDM sumps to 221m and overflows a big streamway down into the far eastern end. We haven't yet seen where that water comes from or goes to (in normal conditions) so that's a big discovery we're looking forward to.  (y)
 
pwhole

pwhole

Well-known member
The drainage is intriguing, not least as there aren't any soughs nearby - at least not until Hill Rake further north. Jim Rieuwerts specifically excluded this section from his Book 1 on the soughs as he stated that the area was more or less entirely drained by the natural caverns of Bagshaw. I must ask him about that - he did tell me he has some fragmentary records on Intake Dale Mine from the late 1600s. I guess if the mine was worked into the 19th Century they should theoretically have just been able to keep driving downwards until they hit the water table if the vein was still producing - being more or less the level of the Bagshawe sumps, as they definitely couldn't lower those any further! But I'm sure there's a lava below it.

I guess Shuttle Rake Mine further uphill must have also drained naturally, at least along the vein - I'll have a look at that when I get a minute. I wonder of that's the source of the water entering at the west end?

Aha - according to Trevor Ford's paper on the Geological Setting of the Mines of the White Peak (Mining History 17:5), the Intake Dale shaft stopped just above the Lower Millers Dale Lava - Shuttle Rake Mine shaft penetrated the full depth of it (50m). No mention of drainage though.
 
AR

AR

Well-known member
I've had a look at the BGS site but unfortunately, there's nothing for the immediate area in the boreholes record so difficult to say. I'd guess that the lava is thinning out as it heads north from Millers Dale but that's just a guess.
 
pwhole

pwhole

Well-known member
Rob said:
So any guess on how deep the millers dale lava is at IDM?
Click to expand...

OK, this is a direct quote from Chris Heathcote's paper in the same Mining History 17:5 A History and Gazetteer of the Lead Mines Within Bradwell Liberty, Derbyshire: 1216-1890, discussing the range of Shuttle Rake from Hazlebadge to The Holmes at the west end:

In Intake Dale the lava was noted as being at a depth of 52 fathoms (95.1m) within the shaft and that it had a thickness of 24-25 fathoms (44-46m), with the top portion being very soft and crumbly (Carruthers and Strahan, 1923).

That reference in full is: Carruthers, R.G. and Strahan, A., 1923. Lead and zinc ores of Durham, Yorkshire and Derbyshire, with notes on the Isle of Man. Spec. Rep. Min. Res. G.B. Mem. Geol. Survey, GB. HMSO, London.

I think I may even have a paper copy of this somewhere. Or it's online here ;)

http://pubs.bgs.ac.uk/publications.html?pubID=B02750

So presumably there isn't yet any toadstone visible in the Hobgoblin's Hideaway? I'm wondering if the standing water there is literally the top of the lava? It must be close to 95m from surface?
 
Rob

Rob

Well-known member
pwhole said:
....In Intake Dale the lava was noted as being at a depth of 52 fathoms (95.1m) within the shaft and that it had a thickness of 24-25 fathoms (44-46m), with the top portion being very soft and crumbly (Carruthers and Strahan, 1923).....
Click to expand...
So would that be interpreted that the original shaft went at least 95+45=140m deep?!?

The engine shaft is currently only 68m deep (from the surface).... and water table expected at 97m at the very most.
 
pwhole

pwhole

Well-known member
Not here, no - the shaft stopped at the top of the lava. In Shuttle Rake mine (which seems a bit hard to define but there is an engine shaft way higher up the hill at SK 1549 7945), they went right through it, so I assume the thickness was determined from there. The lava is shown in Trevor's paper as extending (and dipping) eastwards right under Bradwell Dale and the shales - so presumably the water would tend to run along the top of the lava in that direction until it met natural passage running roughly along the strike toward the village?

The paper is here and the cross-section with the two shafts is on page 38 (of the PDF, not the original doc):

https://pdmhs.co.uk/MiningHistory/Bulletin%2017-5%20-%20The%20Geological%20Setting%20of%20the%20Lead%20Mines%20in%20the%20Northern%20Part%20of%20the%20White%20Peak.pdf
 
Subpopulus Hibernia

Subpopulus Hibernia

Active member
Rob, thanks for being so open in sharing your trip reports and the survey. I know many would hold their cards much closer to their chest on a project like this, so it's great that you're letting us all come along for the ride. Looking forward to seeing how this project progresses, whenever it kicks off again.
 
AR

AR

Well-known member
Rob said:
pwhole said:
....In Intake Dale the lava was noted as being at a depth of 52 fathoms (95.1m) within the shaft and that it had a thickness of 24-25 fathoms (44-46m), with the top portion being very soft and crumbly (Carruthers and Strahan, 1923).....
Click to expand...
So would that be interpreted that the original shaft went at least 95+45=140m deep?!?

The engine shaft is currently only 68m deep (from the surface).... and water table expected at 97m at the very most.
Click to expand...

Some of the Moss Rake shafts were around the same depth as the Shuttle Rake shaft, it's deep but not exceptionally so. I suspect the miners found that sinking those 45m through the lava wasn't worth the effort; the tendency in the Peak is for the veins to be richest either on top of lava beds or in between two beds. High Rake goes into the Potluck Sill IIRC, and they had the misfortune to be trying to sink a shaft into the volcanic vent!

It's not impossible that there's another 30m of engine shaft at IDM; if the shaft wasn't immediately capped when the sparring began then a lot of rubble could have gone down it.
 
Rob

Rob

Well-known member
Subpopulus Hibernia said:
Rob, thanks for being so open in sharing your trip reports and the survey. I know many would hold their cards much closer to their chest on a project like this, so it's great that you're letting us all come along for the ride.
Click to expand...
It's not because I'm weirdly open or wouldn't care if anyone "pirated" the dig. Quite the reverse, cos if some did actually manage to brave the place, find the way, and push on beyond us I'd be very impressed and give then an instant invitation to join the Eldon 😂👍
 
JonP

JonP

Well-known member
We had a massive de-rigging operation last week removing the majority of our gear from IDM. If you wanna go for a jolly take lots of rope and gear (inc. hangers) The engine shaft needs a 70m rope and provides a nice evening jaunt, also if anyone's up for doing a first, we never got around to doing a through trip from the original entrance to the engine shaft via Black Jack Choke - so fill yer boots and let us know if it was worth it!


Stop Flattening Me, IDM by Jon Pemberton, on Flickr
 
pwhole

pwhole

Well-known member
For the record, what size hangers inside generally? 8mm or 10mm? Ironically I've still not done the engine shaft, as the lid wouldn't open last time ;)
 
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