Redhouse Lane on U Tube

[The Old Ruminator]

Rewitten as edit time expired Grrrrrr.

During permafrost conditions near the edge of the glacial sheets water in caves froze solid to become a mass. The movement within the solid mass created breakdown and fracturing of formations clearly seen in Reservoir Hole and Shatter Cave on the Mendips. Over time many fractured formations were covered with more calcite to leave formations like The Leaning Tower of Pisa in Shatter. Also see my recent image on the photo section of the tipped up stal boss in TFD shown again here.



WL Cave shows lateral shearing as solid ice moved withing the passage. With warmer interglacials vast amounts of water were released forming epigenic caves possibly like you have in the FOD. Mendip caves went through cycles as water levels dropped. The transition from phreatic to vadose is clearly seen in Shatter Cave. TFD has superb mud floors having dried and cracked as the water table dropped also residual cryogenic calcite structures on some boulders.

 

[mikem]

Two other videos from 14th and 28th September were also posted yesterday - they can be seen if you go to YouTube itself on original link (the perched rocks are presumably also left by melting ice, whilst tea green marl is later infill)

 

[Rhys]

Two other videos from 14th and 28th September were also posted yesterday - they can be seen if you go to YouTube itself on original link (the perched rocks are presumably also left by melting ice, whilst tea green marl is later infill)

That's the working theory regarding the random perched rocks. Left behind stranded on ledges after partial ice fill melted away.

 

[Tritim230]

We believe the 'black' in Crack in Black is coal, possibly from washings above. We've taken a sample to dry and see if it burns!

 

[Tritim230]

Two other videos from 14th and 28th September were also posted yesterday - they can be seen if you go to YouTube itself on original link (the perched rocks are presumably also left by melting ice, whilst tea green marl is later infill)

The crease limestone is very evident on the video of 14th September as is the abundance of Cryogenic Calcite

 

[The Old Ruminator]

Great geomorphology. Stage grooves and big scallops. You will get the water flow direction from the scallops.

 

[The Old Ruminator]

One wonders if there has been a phreatic / vadose transition here.

 

[forestdweller]

One wonders if there has been a phreatic / vadose transition here.

I would say that is definitely the case. There are many more good examples of this too in further sections of this passage.

 

[Jester]

Great geomorphology. Stage grooves and big scallops. You will get the water flow direction from the scallops.

Is it the pointy end or the round end of the scallop that points upstream?

 

[georgenorth]

Is it the pointy end or the round end of the scallop that points upstream?

The sharp edge of the scallop is the upstream end. i.e. in this photo the water flowed in the same direction that the caver is facing.

 

[PeteHall]

Is it the pointy end or the round end of the scallop that points upstream?

The easy way to tell is to run your hand over the scallops. In one direction, it will flow smoothly and that it the direction of flow.
Running your hand the other way feels much more bumpy.

 

[Rhys]

As an occasional digger and cave surveyor in the Forest, I’ve been fortunate to be welcomed along with the team for a couple of trips helping out in the new bits of Redhouse. It really is a stunning find. The sheer scale of the large breakdown passages is so unexpected and some of the (smaller but still comfortably walking size) phreatic passage shapes further in are really nice. There’s a lack of classic flowstone formations, but tons of other nice features to enjoy. I think people automatically assumed that the cave would just link up with Wet Sink, but at the moment it’s doing its own thing and heading into blank space – which is really intriguing. Credit to Tim and the core team for the hard work and thank you for having me along – it’s really appreciated.

 

[Goydenman]

woooow what an amazing find..... well done for your determination to keep digging. The videos are very good quality and great to watch. Thank you

 

[Tritim230]

The sharp edge of the scallop is the upstream end. i.e. in this photo the water flowed in the same direction that the caver is facing.

Yep. This section is heading west, not that far from Big Sink (fossil downstream towards The Slaughter). Now that connection would be a through trip and a half!

 

[mikem]

The sharp edge of the scallop is the upstream end. i.e. in this photo the water flowed in the same direction that the caver is facing.

Just be aware that in an eddy (giant scallop in the passage) the water will be flowing opposite way

 

[cap n chris]

During permafrost conditions near the edge of the glacial sheets water in caves froze solid to become a mass. The movement within the solid mass created breakdown and fracturing of formations clearly seen in Reservoir Hole and Shatter Cave on the Mendips. Over time many fractured formations were covered with more calcite to leave formations like The Leaning Tower of Pisa in Shatter

And Wookey Hole; there's plenty on show in there which is testament to this proces (off piste from the showcave).

 

[Huge]

Fantastic find! Congratulations to everyone involved. Let's hope there's plenty more to come!

I've got a geology question, if anyone can answer? The passages shown in the videos look incredibly similar to passages in Draenen. Not just the large, bouldery passages but also the smaller, well scalloped passages in the lighter coloured limestone. Passages like Indiana Highway, Raiders Passage and The Canyon, which are formed in the Gilwern Oolite. I know that the limestone in the forest is related to the limestone in South Wales but I wondered if they are actually the same beds but given different names?

 

[The Old Ruminator]

FOD in section.

 

[The Old Ruminator]

FOD in plan.

 

[The Old Ruminator]

I think this is the FOD limestone.
Llanelly Formation


A pale limesone with a significant algal content in places. Still oolitic I believe