When the railway engineers sealed Stone Church Cave they must have thought they’d done a pretty thorough job, and in reading E.D. Ongley’s 1965 BA. thesis, I had thought the same myself, however, on the off chance there might be some surface clues I visited this area with a friend (Jeff) and was immediately able to access the suspected Stone Church Cave as the retaining wall that had been built by the railway has collapsed. Ongley was entirely correct when he theorized that there might have been a buried system in the area, this thought being derived from his observation of an albino crayfish in the railway tunnel.
There is a sizable space that leads off from the railway drainage tunnel and because of blowing air from a hole nearby I suspect that there might still be a tunnel sealed behind the retaining wall on the opposite side of the tunnel as well. When I look at that wall to the right of the above picture I suspect that I can see points from where a tunnel might lead, deeper into the rock. Just because the railway blasted their own drainage route, across the natural tunnel path does not mean that where the water now leaves the rock is where the water always left the rock. There is a low lying area nearby that has been cut off from Stone Church Lake and I wonder if the old drainage route had taken the water that was sinking from the swamp, moved it underground and then either had it meet the surface in that low lying area and from there it drained down through the rubble against the wall of the hill. I noticed that there was a seam of rock about 20 wide in this hollow that was eroded back into the side of the hill. Debris covers the natural seam, but the cleft that is made suggests that the rock is easily worn or decomposed; could this be the subterranean route by which the area is drained?
A surface search revealed a shaft leading down into the natural cave near the upstream insurgence.
To see a short video of the exploration of Stone Church Cave – click here.