Return To Quarter Way Up Hole

Can photogrammetry software help with your ‘scale’ question? Can’t offer a definitive answer but maybe others on here can. Bit of a niche (in every sense) application; over to the hive mind.
Chuck in a toy rabbit for scale. It matters not really as in a while we shall be in there to see for ourselves. It just helps a little to know what to expect.
 
I think Alan Walker and co had a similar scale issue with boreholes into new chambers at Pooles Cavern in Buxton. Ping pong balls dropped into the field of view managed to provide some perspective. Perhaps you could try with a bag of plastic dinosaurs or Halloween decorations to give the image a bit of a "wow" factor? A rubber hand might be good 😊
 
A rock brought out with a micro channel shows it related to a line in the base rock acting as a weak point. I would think that the micro channels are formed by slow drip down the rock face after the phreatic phase. Fairly long ago allowing for the stal to form subsequently. I dont know if these channels have a name. Anastomosis would not be correct as they form as half conduits microscopically. Almost the opposite of scallops really.

 
I think Alan Walker and co had a similar scale issue with boreholes into new chambers at Pooles Cavern in Buxton. Ping pong balls dropped into the field of view managed to provide some perspective. Perhaps you could try with a bag of plastic dinosaurs or Halloween decorations to give the image a bit of a "wow" factor? A rubber hand might be good 😊
This was also done in the Cwm Dwr Quarry some years back through a bore hole with a camera lowered. You can find it in an old issue of Descent. There was a streamway but I don't know what ultimately happened - or can't remember.
 
Might be worth posting this photo taken in Wellington Hole at Portland - again. 30+m inside the cave at sea level. Tony Boycott spotted these scratches and they are puzzling.
 

Attachments

  • scratch web.jpg
    scratch web.jpg
    118.4 KB · Views: 51
  • Tony web.jpg
    Tony web.jpg
    138.4 KB · Views: 52
Yesterday.

An insipid sun hung low over a slate grey sky as the intrepid bird watchers set out across the Somerset Levels. Somewhere in the midst of nowhere way beyond the soggy hamlet of Shapwick the effing road was closed. So back passing the cattle egrets , bottoming the suspension on the bumps ( Road Liable To Subsidence ) and no sighting of the wretched ibis

Along the " normal " route were traffic lights near Walton and a half hour delay. We were going to be late. Got there shortly after eleven. No need to worry as Nigel was listening intently to Peters adventures on Mastermind. Enough bollocks now rhe report.

Took in a base jack, Acro prop and a new poking pole plus assorted lunches. Nigel set to work demolishing the boulder stack in PP with the scaffold pole. The biggest boulder got jammed in the entrance. All to Brian's Delight where mud and boulders flew out in an endless flurry. Peter refusing to go down as it was " too deep ". Lunch time came and I managed to free the jammed boulder at PP. Nigel departed around three so back to PP where an enthusiastic Mr Goldie got the boulder to the bottom ( " I hope you are recording this ". - He was ). Various films, photos and stuff completed for the entertainment of our watching public. I must admit that Peter looks better iin studio makeup.

So to technical bits.

Plan of the Somerset Levels attached ,

Brian's . Delight is about 4m deep taking the bottom to around 179 m OD. Still following the fault wall and reasonably easy digging in smaller rocks and mud though it has to be hauled out. The Fenneario capture to Withyhill is at 167m OD which suggests that this is our base level. Of course we would hope for lateral development south long before reaching that point. At PP the fault is trending SSW away from the known caves ( see compass photo ). It does seem now that as well as intact bedding to the left there is also bedding to the right. Whether that is stable I don't know but the video explains it all. That does give us hope of scaffolding from one side to the other to support the roof. At the furthest point in the choke some 4m in a small hole goes onward. In the centre of PP a large boulder holds back the rubble beyond. It it was gone you could almost walk to the end after clearance. None of that supports the roof so we shall see. PP choke as around 183m OD some 17m below the surface. OD heights on the plan but they are approximate.

Hopefully a full team next week. Maybe we could forego the birdwatching.( Brian ! ). Yet agin I did not get home until 6.45pm and had to microwave my own dinner. Next video seperately
 
Back
Top