Black Ole Bob
New member
Does anyone know how long it takes Phreatic Action to create the larger tubes like those found in Water Icicle Close Cavern, North west passage etc??
And when were they created??
And when were they created??
Very few - I think that you'll find that the vast majority are Pleistocene and Holocene in age.Black Ole Bob said:They have been around for millions of years
Along with the Peak Streamway downstream from Surprise View.4bags said:If you like phreatic tubes, go visit Bakerloo Straight in Dan Yr Ogof, arguably (it probably will be in this forum! ) one of the best in the country....
Pitlamp said:Firstly, streams flowing in phreatic conditions transport often large amounts of sediment and even large pebbles can be directly watched bashing against the roof, floor and walls of submerged passages in high flow conditions.
Imagine what sort of camera would be able to withstand such an onslaught!Paz Vale said:Pitlamp said:Firstly, streams flowing in phreatic conditions transport often large amounts of sediment and even large pebbles can be directly watched bashing against the roof, floor and walls of submerged passages in high flow conditions.
Has this process been photographed or even better filmed particularly the action of the pebbles bashing against the roof.
Never mind about the cameraman!Peter Burgess said:Imagine what sort of camera would be able to withstand such an onslaught!Paz Vale said:Pitlamp said:Firstly, streams flowing in phreatic conditions transport often large amounts of sediment and even large pebbles can be directly watched bashing against the roof, floor and walls of submerged passages in high flow conditions.
Has this process been photographed or even better filmed particularly the action of the pebbles bashing against the roof.
Pitlamp said:There is plenty of indirect evidence of this physical erosion though as well as reports by divers having watched it happening...Thinking about it - I'm sure there are videos of people cave diving in strong currents on you tube in which it's possible to see gravel & pebbles moving fast.
Black Ole Bob said:It seems strange to arrive at that 3 way junction and the whole system apears to be a ridge on the surface??