Poulnagun (B11)

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Contents

Location

It lies 300m south of Ballynalackan School, Lisdoonvarna

Description

Poulnagun (B11) in co. Clare is 20m deep conical depression with tight 14m pitch at the bottom, which opens up after short distance. After 30m low, partially flooded crawl has to be negotiated. Another two pitches, 3m and 12m respectively lead to the streamway. It's believed to be oxbow of Coolagh River on its underground way to submarine resurgence S3 ( Pollsallach, CCSG, p.48). Dye tracing haven't confirmed direct connection with stream that disappears in final sump in Coolagh River Cave however it has showed that the water in upstream Poulnagun sump originates from Poll Cloghaun.

Survey and more info


Previous records

Irish Sump Index, 1988.

14.07.1971 R.Churcher dived for 18m to large flake obstruction

26.03.1978 R.J. Shackleton dived for 9m, current too strong to make further progress

30.08.1982 R.Stanton and S.Joyce made 40m venture into the sump to what appeared to be a junction

01.09.1982 R.Stanton, S.Joyce and S.Gillet pushed the sump for total distance 57.5m. 20m from previous limits passage closed down in a fift. A very low descending passage was noticed in left (east) wall but it was too tight to negotiate. R.S. felt that this was the continuation as the floor here consisted of cobbles, whereas in the rest of the sump it was of silt. Line removed.

Notes

The big boulder on the top of the lower pitch started rocking - it has to be sorted out before next visit.

Recent dives

15.02.2009

Down in upstream sump visibility was very poor, 30-40cm max, stream was reduced to trickle so no flow - once you disturbed the bottom vis was gone completely. There was a bit confusion while in initial 20m of the passage due to extensive chert bands protruding from the walls( I think they finally joint into second floor), but not as bad as I expected. After chert section I found low slot in right hand side wall, just enough to get through feet first without digging. From there on I followed left hand side wall until I reached some kind of low arch. I thought it was the limit mentioned by Rick Stanton so after short clearance I squeezed through. It opened up inside slightly but the floor was quite silted there and I couldn't see a thing  :-[.... At this stage depth was -14.7m. It looked like there was some continuation up but I was out of lead blocks and silt screws and the only belay point was lousy stone 10x10cm so I didn't take a chance in nearly nil vis and low beddings. Return to dive base uneventful. After rereading Rick Stanton's report and checking the line left on my reel I think I got to sort of junction 20m before his 1983 limit. I guess that diving in wet weather would give much better indication of the way on.

Here's trip report from CCC:

http://clarecavingclub.wikispaces.com/dive+1+pollnagun

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