Oxford University Cave Club

'With much rending and tearing of flesh and oversuits we reached the lead. I set up camp - an improvised tent made from a thermal blanket while Doyle put in a few bolts. In no time at all he was at the top, scooping virgin passage. Above the climb there was a free climbable cascade, where the crux involves trusting your weight to a 15cm thick, 2m long flake. Wibble.'
From Erin Lynch's log book entry, 25/7/01

One of the three entrances to the Xitu system, 12/5 soon became known to expeditioners as tight, wet, catchy, cold and miserable! This may explain why it took so long to rig, and the haste with which it was de-rigged. The aim was to rig down 600 metres and find the way into the often-postulated fossil levels at that depth. The search for these levels, via a window in 'The Heath' pitch, was unproductive. However, a search high in the rift above 'The Mendip Bit' at -450m revealed a new inlet.

Description

Survey

From the bottom of 'The Icing on the Cake,' instead of following the water, climb up to the left into a traverse through rift. Over some large jammed boulders and a right hand bend leads to a temporary floor with water trickling down the muddy right wall. Follow the traverse for about 20m past a too tight left fork, round a right hand bend, and up out of a trench into a chamber, 3m wide and 5m long, with several boulders lying around. A giant slab, the size of about three or four cavers, leans against the wall.

Here you can head back the way you came at a higher level (with floor), soon meeting a t-junction. Both directions lead to some very pretty stal/helictites and flowstone (take extreme care), but the passages both close down after about 20m and were not surveyed for fear of breaking formations.

From the trench, you can continue under the giant slab towards the sound of water, soon reaching a 2m waterfall. The flow disappears down too tight passage in the floor, presumably reconnecting with the main 12/5 streamway at an unknown point. The way on is a 3m scramble up to the right of the waterfall away from the stream, and here things get tight, scratchy and nasty. Layering of dark (almost black) and light rock is evident, and it is all very chossy and crumbly, providing a name for the inlet. What follows is a 10m traverse heading upwards, eventually breaking through into a 6m diameter aven, 15m high, with a 2m wide, 0.5m deep pool in the floor, fed from a waterfall from the top of the aven.

From the floor of the aven, head back in the direction you came from, but at a higher level, to enter a crack, where it is easy to free climb to a ledge halfway to the top of the aven. Here was the start of a bolt climb up the right hand side of the crack, eventually gaining floor at the top of the waterfall. There follows straight away a 4m cascade, which can be free climbed with care to reach another aven with another waterfall. We couldn't see the top of this one, so things stopped there.