Hypogenic Cavern Development on The Quantocks, Somerset ?

[The Old Ruminator]

I present this video of recently discovered small natural caverns aligned along a baryite vein within the Devonian Limestone in the Quantock Hills. My theory is that they are hypogenic in origin and like other Quantock caves largely filled with sediment and detached boulders. This short video shows the baryite wall along which the small cavern is aligned.

https://flic.kr/p/2nMYPo6

 

[The Old Ruminator]

A little more here -

Hypogenic Cave Morphology

We are just getting used to cryogenic structures . Here is another emerging cave science where we might find instances in the field. "Hypogenic speleogenesis is the formation of solution-enlarged permeability structures by waters ascending to a cave-forming zone from below in leaky confined...

ukcaving.com

 

[The Old Ruminator]

A current dig. Bottom left hand corner is the baryite wall. Ahead is Devonian Limestone. The wall marked 1 has been detached and removed as has the boulder marked 2. Boulder 3 blocks the downward progression of the baryite development.

 

[The Old Ruminator]

Baryite / Limestone interface from Cannington close to the Quantocks where a large cavern existed in the 1970's. ( Jackdaw Cave ). Baryite was dug here from surface pits.

 

[The Old Ruminator]

Baryite with Malachite from Cannington.

 

[The Old Ruminator]

Cavern development and baryite at Cannington. Note that this site is not open to cavers.

 

[The Old Ruminator]

Still digging after nearly 60 years. My first major discovery at Holwell Cavern 1964. A complex maze cave oriented along dip and minor faults surely of hypogenic origin.

 

[The Old Ruminator]

Note Holwell Cavern is not blocked but access is denied.

 

[The Old Ruminator]

Porifera fossil sponges exposed by hypogenic solution. Quantocks.

 

[The Old Ruminator]

Baryite with Malachite. Quantocks.

 

[The Old Ruminator]

Possibly Ochre on Devonian Limestone partly dissolved by hypogenic action. Quantocks.

 

[The Old Ruminator]

Any more erudite amendments welcome.

 

[The Old Ruminator]

Fused calcite helectite mass from Cothelstone Hill Cave, Quantocks.

 

[The Old Ruminator]

Fluvial copper from the Quantocks.

 

[The Old Ruminator]

Whilst copper was mined on the Quantocks it came as a fluvial deposit within the baryite lode not as an ore. Mostly it was processed underground by the miners but never proved an economic proposition. Copper extraction finally ceased in 1821. ( Refer - "Men and Mining on the Quantocks." ) The miners worked what they called the spar lode ( baryite ) and the margin of the Devonian Limestone and Slates. Caves have formed where the slates overly the limestone at Holwell. Aisholt and Cothelstone. The miners referred to the non productive slates as Killas . This unconformity is well exposed in some remote Quantock quarries

 

[The Old Ruminator]

Typical lithology in section showing the Quantock Limestone and Slates.

 

[The Old Ruminator]

Devonian Limestone surface outcrops on the Quantock Hills. The western progression halts at the Cothelsone Fault which crosses the SW Peninsular.

 

[The Old Ruminator]

Slate/Limestone interface at Cothelstone Hill Cave.





The distorted nature of the slate beds can be seen.

 

[The Old Ruminator]

Me at Aisholt in the 1960's. Note the quarry is now privately owned and closed to visitors.

 

[The Old Ruminator]

Me and Rodney Pike at Holwell c 1963.