Yorkshire Lad
New member
Not with my thumbnail, but scratched it with a bit of gravel.If you can scratch it with your thumb nail
Will be calcite .
Everything goes back to the moh”s table .
Not with my thumbnail, but scratched it with a bit of gravel.If you can scratch it with your thumb nail
Will be calcite .
Everything goes back to the moh”s table .
Have you checked on the BGS website ?View attachment 1643so this is a photo I took last summer in an old quarry near Mylor Creek in Cornwall, I have been wondering for some time as to what it maybe.
I don’t know if it’s obvious, but it’s a mineral vein running over base rocks.
I suppose the obvious question is, why were they quarrying here? Were they looking for this mineral or was it that they wanted the rock and we’re discarding the minerals?
If it’s any help the grid ref of the quarry is: SW 812 357
Here’s another photo from the same location, again strange geological occurrenceThe quarry is in the Porthleven Breccia Member of Devonian Age. God knows what they'd be quarrying from that. I'm not convinced that's a vein per se, but it certainly looks like a bit of a crush zone or fault. We need someone with a bit more rock info on this one!
Looks like Britannia Mine stuff.My chalcopyrite finds, from walking mount Snowdon .View attachment 790View attachment 791View attachment 792View attachment 793
Yep know that one well. I grew up in Harrogate and Knaresborough was where i started to get interested in proper geology walkiing along the gorge with parents on a Sunday outing. The Cadeby Formation is Yorkshire is one of my private research topics looking at the associated mineralisation within the Formation.If you like unconformity you should visit my home town of Knaresborough where on my daily commute I cycle past Addlethorpe Grit, a Carboniferous Sedimentary Sandstone 322 million years old over lain by Dolostone of the Cadeby Formation, a Permian Sedimentary Siltstone 272 million years old old. Somewhere there are 50 million years of rocks missing!
Just folded as part of the roof fall deforming the soft shales. Disseminated Pyrite in the shales chemically reacts in contact with air and water producing Ferrous Sulphate , a mineral called Melanterite which are the brown areas. The process also forms sulphuric acid which reacts with any calcium carbonate in the shales to produce gypsum - the white mineral on the right hand side of the photo. The disruption of expansive minerals forming weakens the roof layers and they peel off.View attachment 1899
Some folds in a coal mine. Could something like this have happened after the Coal had been taken?
I thought it was just meIf you like unconformity you should visit my home town of Knaresborough where on my daily commute I cycle past Addlethorpe Grit, a Carboniferous Sedimentary Sandstone 322 million years old over lain by Dolostone of the Cadeby Formation, a Permian Sedimentary Siltstone 272 million years old old. Somewhere there are 50 million years of rocks missing!
Missing one, I think - there's the remains of a Copperas works at Ringinglow to the west of Sheffield at SK 2934 8340,. I've a feeling it's listed, I'll have a look on Magic.Several coal mines used to mine and sell the iron sulphate which was colloquially named copperas.
We've got a couple of examples in the databse -
Not only are the rock interesting at Knaresborough, but further up the gorge, are the remains of Medieval Coal Mines along Bilton Banks, and just before you get to Ripley some old limestone quarries.I thought it was just meat Easter I was in Knaresborough, performing the touristic tedium of over busy main car park, tea and slice of cake in Riverside cafe, then up steps to the castle -- all the time wishing I was doing something more worthwhile and subterranean. However Mrs cantclimbtom and accompanying friends are very much cake not cave. Anyhow... I got told off for overly admiring the rocks by the river and up to castle not noticing the boats etc. Didn't get chance to look that closely but there's some variety there, not all of one type. Immediately obvious that it's somewhere interesting geologically
Yep remember visiting them. Then there is the cave at Old Mother Shiptons with the petrified items sitting in the spring flow.Not only are the rock interesting at Knaresborough, but further up the gorge, are the remains of Medieval Coal Mines along Bilton Banks, and just before you get to Ripley some old limestone quarries.
Haven’t been there in an age… gotta pay to go in!Yep remember visiting them. Then there is the cave at Old Mother Shiptons with the petrified items sitting in the spring flow.