Silly question about Leicestershire Slate

[Cantclimbtom]

is your post erratic?

 

[grahams]

I used to climb a fair bit in Leicestershire, and it’s a bit of a gem in the midlands. The geology is really varied for such a compact area, with granite at swithland reservoir and mark field quarry (near to the exposed rocks on the M1 which I thought of as a fine grained granite but maybe andesite.). Plenty of slate in the wood house eaves area, with a shortish quarried tunnel in forest rock. There’s also Horn stone at Beacon hill, which polishes very easy and incredibly dense.

I used to climb at Markfield back in the 80s. There's a disused quarry at Huncote which had some good looking routes back then. Over the hill from Huncote is what appears to be the deepest hole in Britain but they don't seem to be leaving behind any climbable rock for future generations due to tiering.

 

[mikem]

... Over the hill from Huncote is what appears to be the deepest hole in Britain but they don't seem to be leaving behind any climbable rock for future generations due to tiering.

T'internet suggests, in the red corner (Cornwall): https://www.atlasobscura.com/places/delabole-slate-quarry
& the blue corner (Aberdeen): https://en.m.wikipedia.org/wiki/Rubislaw_quarry

 

[Cantclimbtom]

I used to climb at Markfield back in the 80s. There's a disused quarry at Huncote which had some good looking routes back then. Over the hill from Huncote is what appears to be the deepest hole in Britain but they don't seem to be leaving behind any climbable rock for future generations due to tiering.

Depends how tall each tier is, it worked out very well in Dinorwig!

 

[legendrider]

If you look at the geological map of the area, it's all Triassic with inliers of Pre-cambrian all over the place. Reading my BGS regional guide last night, it appears that the Triassic was deposited as a veneer onto a 'fossil' Pre-cambrian land surface, with the topographic highs now appearing as 'windows' into the Pre-cambrian. Didn't David Attenborough go searching for fossils here?

Yes, this is the locality from which Charnia masoni gets its name. 'Charnia' was a soft-bodied organism whose fossil was discovered by a schoolboy in the 1950's - looks a bit like a laurel leaf, although 'quilted' in form and with a basal holdfast to the seafloor. Further similar fossilised fauna were discovered in the Ediacara Mountains in Australia, and the pre-Cambrian geological period to which they belong was subsequently named the 'Ediacaran'. Debate continues regarding the affinity of these early organisms, which disappear from the fossil record by the early Cambrian (541mA)

 

[ttxela2]

I skimmed through a video about RAF Colleyweston (interesting that from 1943 onwards they flew captured German aircraft from there) and near the start there's some driving about footage and many of the buildings have Colleyweston "slates".
Looks very nice, rustic, goes with those buildings nicely. Must have come out of the underground quarries that you posted a pic?

Years ago I did a course in Historic Building Conservation through Cambridge University's ACE scheme. The Tutor was a planning conservation officer and we visited Collyweston (before the underground quarry reopened). There was a lot of interest from the local planners in the slates and ensuring they were preserved. I imagine the quarry is kept quite busy providing materials for repairs and extensions etc.

 

[Graigwen]

I know very little about Leicestershire slate but did come across a strange export use some years ago while doing historical research. The so called slate was used to a limited extent for gravestones. When moderately well off locals settled in America in the seventeenth or eighteenth centuries they would sometimes take blank gravestones with them. When they died in America decades late, the required details could be carved onto the stones.

I can't remember many more details but found this article by Albert Herbert in the Transactions of the Leicestershire Archaeological and Historical Society, Vol 22 (1941) pp. 211-240:

SWITHLAND SLATE HEADSTONES

.

 

[Roger W]

Leicestershire slate gravestones in the USA?

That could give archaeologists a headache similar to the origin of the Stonehenge bluestones and how they got there!

 

[Cantclimbtom]

Leicestershire slate gravestones in the USA?

That could give archaeologists a headache similar to the origin of the Stonehenge bluestones and how they got there!

I don't understand why the bluestones are "interesting", looking at the directions and limits of glaciation events on a map, why are they not just viewed as erratic boulders, like the big lump of Whin sill in Southern Essex (now in Bedford's park https://en.wikipedia.org/wiki/Bedfords_Park) dug up in local gravel pit). But maybe the Flying saucer tractor beam or 10,000 slaves with log rollers are more exciting explanations?

 

[Jim MacPherson]

I don't understand why the bluestones are "interesting", looking at the directions and limits of glaciation events on a map, why are they not just viewed as erratic boulders, like the big lump of Whin sill in Southern Essex (now in Bedford's park https://en.wikipedia.org/wiki/Bedfords_Park) dug up in local gravel pit). But maybe the Flying saucer tractor beam or 10,000 slaves with log rollers are more exciting explanations?

In part because it appears all or some of them were used in an earlier henge in the Preseli hills quite close to one probable quarry, so glacial erratics would seem unlikely.

Jim

 

[ttxela2]

In part because it appears all or some of them were used in an earlier henge in the Preseli hills quite close to one probable quarry, so glacial erratics would seem unlikely.

Jim

I wonder if whoever commissioned it ever realised the contractor was using reclaimed materials.....

 

[Cantclimbtom]

I wonder if whoever commissioned it ever realised the contractor was using reclaimed materials.....

Nah.. it was a heritage/cultural project, that gets extra brownie points

 

[Andy Farrant]

Just to be very very clear, the Stonehenge bluestones are NOT glacial erratics. Having mapped much of Salisbury Plain, there is zero evidence for glacial activity that far south. There are no tills, glacial erratics or landforms suggestive of glacial activity anywhere on Salisbury Plain. The only far travelled material are river terrace gravels, and even these are predominantly of local origin.

 

[Cantclimbtom]

Thanks, I was under the impression that the Anglian stopped right there https://clivebest.com/blog/?p=7089 just on the north edge of the plains, maybe that's wishful thinking rather than evidence based?

 

[Andy Farrant]

The figure showing the glacial extents in https://clivebest.com/blog/?p=7089 has shows the ice extending to cover both the Mendip Hills and Salisbury Plain. The figure comes from this website: https://brian-mountainman.blogspot.com/2012/08/british-glacial-limits.html. It has been tweaked mainly to justify (without any evidence) the notion that ice transported lots of large bluestones to Stonehenge. I find it hard to belive that the ice would selectively transport some large bluestones (and nothing else) from Pembrokeshire to Amesbury in Wiltshire without leaving any other glacial erratics in its wake, depositing till or producing any glacial landforms. The reason why 'brian-mountainman' has published this in a blog rather than an acandemic journal is because it would be shredded by any competant reviewer. The Anglian ice margin was much further north in the Cotswolds - see Fig 1 in http://earthwise.bgs.ac.uk/index.php/OR/15/064_Introduction.

 

[droid]

If you look at the geological map of the area, it's all Triassic with inliers of Pre-cambrian all over the place. Reading my BGS regional guide last night, it appears that the Triassic was deposited as a veneer onto a 'fossil' Pre-cambrian land surface, with the topographic highs now appearing as 'windows' into the Pre-cambrian. Didn't David Attenborough go searching for fossils here?

Yes.

I think Trevor Ford cut his teeth round there too.

It was a pupil at Attenborough's school that found the Charnia specimen

 

[Graigwen]

In part because it appears all or some of them were used in an earlier henge in the Preseli hills quite close to one probable quarry, so glacial erratics would seem unlikely.

Jim

The original setting in Preseli was called the Giants Dance. It was moved to Salisbury plain by Merlin. At least that was what Geoffrey of Monmouth said in his Historia Regum Britanniae, although he had it starting in Ireland.
.

 

[koalageo]

If you want some more background reading check out:

Page 1

specialcollections.le.ac.uk

charnwood-forest-geology/Mercian_2007_v16_p241_Chranwood_quarries_McGrath.pdf at main · KoalaGeo/charnwood-forest-geology

Themed Walks. Contribute to KoalaGeo/charnwood-forest-geology development by creating an account on GitHub.

github.com

charnwood-forest-geology/1988_(62)_1-8_McWhirr.pdf at main · KoalaGeo/charnwood-forest-geology

Themed Walks. Contribute to KoalaGeo/charnwood-forest-geology development by creating an account on GitHub.

github.com

& finally - https://koalageo.rocks/charnwood-forest-geology/#/

 

[mikem]

& Geoffrey of Monmouth thought the stones had originated in Africa:

Giants’ Dance

wshc.org.uk

 

[Cantclimbtom]

& Geoffrey of Monmouth thought the stones had originated in Africa:

Giants’ Dance

wshc.org.uk

Giants are a bloomin' nuisance to geologists and archeologists. Building their causeways, moving henges and dropping big boulders erratically to try to confuse geologists. I hope this government will take a firm stand against their menace. Although digging a big hole in Derbyshire wasn't such a bad idea but did lead to confusion with some still believing it's some sort of cave rather than giant's mine