A very good question.It's origin, yes - but how much of its current morphology has developed since?
Most were changed significantly by the last ice age (& not as much since), except those bits that have formed more recently...
Such scraping would cause the overlying beds to be stripped away, leaving formerly closed avens as open shafts.
Not to hand I'm afraid, but without it there would be no limestone pavement or erratics. Overlying pressure of ice could well collapse a cave roof, and this has to be a mechanism in some cases. In either case I would expect a lot of debris to enter the open cave, unless the void was ice filled during glaciation?Interesting. Have you a reference for glacial ice stripping away surface beds in the Dales? I would have thought that collapse caused by the sheer weight of a couple of hundred metres of ice (and its subsequence removal) would be a far more convincing hypothesis for the opening up of avens to the surface.
Are we assuming Alum Pot Main Shaft was an underground chamber which was then breached from the surface by whatever mechanism? I find this hard to accept as there's no evidence of resulting debris, other than the Bridge jammed across the shaft, which could easily have just peeled off the walls (freeze / thaw action?).
I'd have thought Alum Main Shaft is an (almost) abandoned ancient open sink on the N / S fault, with the present Alum Pot Beck being an underfit stream (due to the main stream having been captured by subsequent underflow via the Long Churn system and associated caves).
In your previous post you said that "I think the limestone pavement common in the dales is the result of glacial removal of soils.", which is contradictory!Not to hand I'm afraid, but without it there would be no limestone pavement or erratics.
Confusion reigns...In your previous post you said that "I think the limestone pavement common in the dales is the result of glacial removal of soils.", which is contradictory!
My understanding is that you are right that glacial ice did remove weaker beds to expose the harder beds, but I find it hard to accept that was responsible for the existence of the surface shafts we see today such as Alum Pot (any more than collapse from the weight of ice!).