Eldon Series, P8.

[bograt]

Having cause to browse through some of my archive, I came across an article by 'Ben' Bentham about his work in the Eldon Series in P8, (DCA Newsletter 63, October 1986), a passage 7 feet (2 metres*) in diameter ---.
Anyone been up there lately?


* - Form an orderly queue for the pendant award, can't be arsed to be more accurate :

 

[Rob]

We spent some time looking up there a while back when we were pushing Gautries. Some definite similarities in passage shape to some of Gautries' 2010 extensions, which is ~440m away on a very similar elevation.

Some SUSS chaps were up there in 2014 doing a resurvey for the 3D survex file, which is how i know this. 

The big passage is indeed a beauty, albeit only sustained for a few meters before hitting the end pot. The floor here is dry solid mud, not an enticing prospect but certainly a good location.

 

[Tommy]

Is this the bit in Christmas Aven Rob?

 

[Rob]

Is this the bit in Christmas Aven Rob?

No, it's below that, up beyond "Ben's Dig". Should be labelled accordingly here:
https://www.dropbox.com/s/el4x54kd78h3gvs/P8_Master.3d?dl=0

 

[bograt]

Some definite similarities in passage shape to some of Gautries' 2010 extensions, which is ~440m away on a very similar elevation.

Now that's interesting, there's two active swallets and Bull Pot between them  :-\ :-\

 

[Tommy]

Is this the bit in Christmas Aven Rob?

No, it's below that, up beyond "Ben's Dig". Should be labelled accordingly here:
https://www.dropbox.com/s/el4x54kd78h3gvs/P8_Master.3d?dl=0

Thanks for that, is it meant to render like this? Or does my machine just not like surveys...

 

[Mrs Trellis]

I always thought that Ben's series was heading for the surface.

It would be good to put some nearby entrances on the survey just to see where it's coming out.

 

[Brains]

I always thought that Ben's series was heading for the surface.

It would be good to put some nearby entrances on the survey just to see where it's coming out.

Back in the day it was widely rumoured / known that the series had been dug to surface but blocked up due to the farmer only wanting one entrance...

 

[Rob]

Thanks for that, is it meant to render like this? Or does my machine just not like surveys...

Yes that looks "correct". Survex can only display 3d passage tubes very simply, so in areas where you've done lots of legs to add detail you get a messy 3d shape.

I always thought that Ben's series was heading for the surface.

Part of it is. Half way along an aven series comes in which gets very close to the surface. I too have heard rumours of it once connecting via uncertain methods,  although never passable.

The main continuation West is big and very phreatic in nature and I would guess comes from a good distance away (rather than local inlets).

 

[2xw]

The xmas aven dig is almost at horizontal now, i will be interested to see how any further passage morphology compares.

 

[pwhole]

Just out of interest, the high aven in Gautries just before the unblocked sump - how high is that exactly? Does it line up with the high-level stuff in P8? Just interested in where it is in relation to surface, as it doesn't seem to be on the Castleton Survex model - at least the full vertical extent of it. I'm guessing it's station 37ab on the big Survex model where it finished.

 

[Rob]

The xmas aven dig is almost at horizontal now...

That's awesome news. Keep at it, some answers must be close! 

Just out of interest, the high aven in Gautries just before the unblocked sump - how high is that exactly? Does it line up with the high-level stuff in P8? Just interested in where it is in relation to surface, as it doesn't seem to be on the Castleton Survex model - at least the full vertical extent of it. I'm guessing it's station 37ab on the big Survex model where it finished.

Yes station 37ab is the bottom of the "Great Aven", but all the detail I have is an "up" shot of 7.2m (which i would say is not to the top). That would put the top at ~20m below the surface, so still plenty to go at. Anyone know if/when it was climbed last?

Not sure if it can be projected to P8 meaningfully, but it does get close to the upper bedding in Gautries, as does the top of Arrods. NB most of Gautries is in the reef limestone and the beddings are at 45? (dipping to the North East).

 

[pwhole]

I climbed it as far as I dared on the only time I went there - maybe 10-12 metres, but it was all getting a bit sketchy without any aids. I'm a better climber now, so might do better, but I haven't seen any descriptions of climbs to the top. I'm guessing Les Salmon and co must have as I'm sure it's on their old survey. Eddie Mason might know.

 

[pwhole]

Eddie says it was the Eldon who climbed the Great Aven - he was only chatting with Bob T about it last week! He's going away for a few days but says he can dig through his records when he gets back, though Bob can probably help - it's definitely blind at the top, but a height would be useful anyway.

 

[A_Northerner]

Some SUSS chaps were up there in 2014 doing a resurvey for the 3D survex file, which is how i know this. 

That would be this SUSS Chap! (and Jeff). We made it to the top and found that after a flat out crawl which heads up into an aven there is fresh(er) air and overhead mud to be dug out. We presumed the reason it hadn't been dug was that the farmer didn't want another entrance. Access from this potential entrance wouldn't require any SRT (providing the installation of a handline on a certain flowstone climb) and would cut the time to the bottom of P8 in half, at least.

However after looking at the data we found that this particular passage is indeed not the highest point on the survey - which you quite rightly say is "Great Aven". We were running low on time and there is a sketchy calcite choke at the top of the "7.2m leg" which Jeff didn't want to go through - I haven't yet explored beyond this but have been meaning to (I can never convince people to go up to Ben's Dig when we take fresher's trips down there!).

Maybe I should take a look while the rest of SUSS are making their own breakthroughs in Xmas Aven?

 

[Tommy]

Maybe I should take a look while the rest of SUSS are making their own breakthroughs in Xmas Aven?

I'll go with you sometime buddy, keen to explore the nooks and crannies a bit more.

 

[Rob]

However after looking at the data we found that this particular passage is indeed not the highest point on the survey - which you quite rightly say is "Great Aven". We were running low on time and there is a sketchy calcite choke at the top of the "7.2m leg" which Jeff didn't want to go through - I haven't yet explored beyond this but have been meaning to (I can never convince people to go up to Ben's Dig when we take fresher's trips down there!).

Yer, i think there's a bit of misunderstanding here. To try to add some clarity:

• The "Great Aven" referred to previously is in Gautries.
• I believe the aven in P8 that got very close to the surface is station bens_dig.217

Which station represents where you found "a sketchy calcite choke"?

 

[bograt]

• • The "Great Aven" referred to previously is in Gautries.
  • I believe the aven in P8 that got very close to the surface is station bens_dig.217

  Which station represents where you found "a sketchy calcite choke"?

  
  Thanks for that clarification Rob, I was beginning to get confused  :blink: ! ---.
  
  And also, a sketch of where the Christmas Aven dig is going would be good? - is it relevant or is it 'out of reference?' --

 

[2xw]

And also, a sketch of where the Christmas Aven dig is going would be good? - is it relevant or is it 'out of reference?' --

Its heading pretty much due west. If we are right, in that once it gets down to the same level as the horizontal phreatic leading into xmas aven, the dig will soon go horizontal. Approx. 25 metres of horizontal passage moving west would see the dig directly above "Top Sump" or sump B/III, but 25m higher up. (metre lengths very approximate!)

 

[A_Northerner]

The choke is at point 27 - Jeff and I climbed up to it but didn't want to go on (it has been worn a bit though). Now I've taken another look at the Master Survey (I had an outdated version from Day 2 of our surveying) point 217 is above 27 by a small amount, however point 27 definitely has potential to go higher, whereas point 217 has reached its termination without digging.