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New stream cave in the North York Moors?

Cavematt

Active member
Up in the North York Moors, we have been treated to some great discoveries over the last decade, including a 1km+ extension to Jenga/Excalibur Pot in 2020.

However, all open and obvious leads in Jenga/Excalibur are now exhausted (except for the four sumps which await divers and are sure to add hundreds of metres more passage and possibly the fabled link to the River Dove or Bogg Hall). Also, accessing the Jenga extensions is not viable October to April due to flooding. Hence we have been on the lockout for our next project.

Should we return to some of our more speculative, uninspiring digs? Manor Vale? Mutton Butty? Glass Trap? Enthusiasm was not high for any of these.

Thankfully, last summer, a new project came to light at a site we have been interested in for some time, where a change in land ownership has now enabled consented access for a dig. This site is near to the village of Cropton, 4-5km east of the Jenga/Excalibur system, at the top end of the limestone.

Here, a small stream (which only flows when the ground is saturated) disappears into the ground at the top end of the Jurassic limestone, at the end of a usually dry valley, with about 3-4km horizontal range and 50-60m vertical range to where most of the regions resurgences are found.

Progress was slow, as getting down through several metres of upper non-limestone rock was challenging. Thankfully the really friendly landowner was on hand with a JCB to expedite this, getting us down 4m into a small, dry cave passage leading off into darkness.

This passage was not straightforward. We were not properly into the top of the limestone yet, so the roof had flaked large slabs across the passage where it has collapsed in multiple places, and progress through Autumn and Winter has involved pushing along the passage, removing boulder obstacles. At times it has felt like an underground boulder labyrinth, but in fact we are following a large passage, just one full of blocks. Progress has sometimes been only 1m per week!

The draught is excellent here, and the prospect of sinking water nearby kept us going.

It was at some point in November that the first heavy rain of winter happened and the sinking stream (The Shite Brook) suddenly entered the cave about 10m along the passage, bringing with it some foul smells for the first week of flow until it flushed through whatever the offending matter was.

The stream flowed off tantalisingly through boulders, accompanied by the ever-present-draught.

More boulder mining identified that we had now achieved a solid, water-worn roof, and solid cave walls in a passage 2m wide by 1.5m tall. The challenge was a number of large slabs that continued to block the way. In the sessions just before and during Christmas more blocks were cleared, and ahead, the most enticing black voids yet appeared, with the sound of the stream gurgling into the distance.

On 4th January, after a few more hours of boulder removal, we got a mini breakthrough and crawled forward 10m just above the stream and into a 5m long, 2m wide chamber with a few formations. At the end of the chamber is a way on, flat out in the stream and going off several metres, with no end in sight. This is our target for this week, although some dodgy blocks need to be stabilised first and the stream may need some dredging of cobbles.

We are now about 30-40m into the cave in total. The further in we get, the more water-worn it becomes, the more cave-like and phreatic it appears, and the more space we are getting between obstructing blocks (although we are far from clear of these). Plus, there is a stream vanishing into the cave and a strong draught either howling in or out (typically out, but last week it was strongly drawing in).

What we do have here for sure is the second, explorable, active stream cave in the North York Moors, if you count the entire Excalibur/Jenga/Bogg Hall/River Dove as one cave system.

Excitement is mega-high for the coming weeks. Will we get through the boulders and into glorious stream passage heading off down the valley? Will this become the second North York Moors mega-system? Or is this going to become a several year mining project through hundreds of metres of block-choked streamway? Is it going to spontaneously close down to an impenetrable wet bedding? Time will tell, but we are feeling fairly upbeat right now.

In the meantime, we have put together the following video from the session last week with the mini-breakthrough and open (albeit small) passage ahead. Enjoy…

 

Cavematt

Active member
Ps; I should have said... there is some very bad language in the video, in case anyone is easily offended.
 

Goose 777

New member
That is an interesting read... I live near the North York Moors. Can anyone tell me where the nearest caving club is to the North York Moors. I used to be in the Aberystwyth caving club:) thanks
 

Cavematt

Active member
Hi Goose 777, your nearest club will be our digging companions, the North York Moors Caving Club:

 

Cavematt

Active member
A fun evening last night up at the new cave, and a good turnout of YCC and NYMCC members, despite it being a bitterly cold evening. It was fairly dry though (contrary to the Yorkshire Dales at the moment… being on the east side of the Pennines has some advantages).

By the time everyone was underground we found ourselves with eight people in the small chamber just before the active face. A few people started work dredging the flat-out crawl in the stream ahead ready for the push along it, while the rest of us manhandled blocks to create a large pillar underneath one particularly concerning large slab in the roof. Whether this will provide any protection if the slab falls, we don’t know, but it certainly made us feel better about being there.

The low streamway was pushed for 3m to where it rose up over blocks and into a crawl over slabs with the streamway below. Another 5m onwards the first pushers encountered a large block which would need a squeeze to get past, so they returned to report and then everyone took it in turns to go and inspect the situation (which took the best part of the evening).

The squeeze was pushed by a few of the thinner diggers, but only for another few metres to a point where the way on is clearly back down to the stream, as the overhead passage seems to run out. Sadly, getting back down to the stream was obstructed by slabs.

We’re going to need a few weeks of work to deal with this before we can push further. This will include engineering a route over the flat out crawl in water (for comfort rather than necessity) and then dealing with some of the slabs that prevent continuation at stream level beyond.

The way onwards in the stream isn’t massive, but it’s a definite small stream passage, crawling height, and still draughting nicely. The passage is dropping considerably and we are hopeful that not far ahead we will find ourselves into a better quality limestone capable of having developed more.

The streamway at the active face is very reminiscent of the likes of the Honey River Series in Excalibur Pot.

The dream is that this is an inlet into a system that will develop further downstream into something bigger. We’d love to think this could become the next Excalibur/Jenga, although we remain firmly grounded in reality that it could close down at any point, or there could be years of work ahead (not a problem... we have lots of time).

The total passage length so far is probably about 50-60m.

The resurgence is unknown. One possibility is Keld Head in Pickering, which is over 100m lower in altitude (much more than I quoted in the video) and over 4km away. We know that Keld Head is the resurgence of a lot of water from various sinks across the region, with the water rising up through the gravel floor of the pond, producing a substantial river in wet conditions (you can actually see the gravel at the bottom of the pond churning from the upwelling water). There are also likely to be numerous other smaller resurgences in the Sinnington to Pickering area, still with 90m+ vertical range. This is more than double the vertical range Excalibur Pot has from its resurgence!

Lots of work to do, and no stomping stream passage yet, but we are pretty excited nonetheless. This is probably the best prospect outside of the Jenga/Excalibur region we have ever had. Together with this, and assisting divers to the Jenga sumps over summer, our digging calendar for 2023 is fully sorted.

:dig::dig::dig:
 

Leclused

Active member
The resurgence is unknown. One possibility is Keld Head in Pickering, which is over 100m lower in altitude (much more than I quoted in the video) and over 4km away. We know that Keld Head is the resurgence of a lot of water from various sinks across the region, with the water rising up through the gravel floor of the pond, producing a substantial river in wet conditions (you can actually see the gravel at the bottom of the pond churning from the upwelling water). There are also likely to be numerous other smaller resurgences in the Sinnington to Pickering area, still with 90m+ vertical range. This is more than double the vertical range Excalibur Pot has from its resurgence!


:dig::dig::dig:

This looks like a nice DYE-tracing project :) Perhaps you can contact traqua to sort out some material for the tracing. The have a sponsorship procedure for dye-tracing caving projects

More information here : https://ukcaving.com/board/index.ph...eters-for-scientific-research-projects.29523/
 

Graigwen

Member
That is an interesting read... I live near the North York Moors. Can anyone tell me where the nearest caving club is to the North York Moors. I used to be in the Aberystwyth caving club:) thanks

Hi Goose, when were you at Aber?

Did you go to the 2016 reunion or were you one of the people I could not find?
.
 
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