A Geological question.

[Whitewater]

I have in my possession a copy of an old 17th century map. It is "A Geometrical Survey of the Harbours, Rocks and accounts of the tides of the Pentland Firth" It was commissioned by the Philosophical Society of Edinburgh.
It has many notes on it regarding the north coast and points of interest in Caithness and Sutherland. However, I'm really puzzled by one particular note. Here it is, exact wording:
"In several places of Caithness there's a grey stone which burns as bright as a candle without having its figure changed by the fire"
Do any of you amateur or professional geologists know what could have caused this? and if so, does it, or can it still happen?

[Tubthumper]

Never heard of that before (and I know nowt about geology) but I reckon if you can identify the stone you're set for life! And we wont need any more wind or sea turbines.

I'll help out with the digging, we can split the profits half each? ;)

[gleeber]

That's interesting. It makes no sense. I wonder if the early members of Scotlands philosophical societies were still endowed with the artistic writings of the early Jews who wrote the bible.

[Tubthumper]

Could it be some kind of oil-bearing shale?

[gleeber]

Ive raked about quarries most of my life and theres nothing like that I know of.
My guess is whoever wrote it was using poetic license.

[Tubthumper]

Maps were much more interesting then, almost works of art. WW, you're lucky to have got it!

Gleeber, where can I apply for a poetic license?

[gleeber]

You already have one.

[Whitewater]

Could it be some kind of oil-bearing shale?

There is some oil bearing shale in the county, but I don't know if that is the answer, it would take something to igniite it. The impression given by the note is that it seems to be natural. I also wondered if it could have been glowing rather than burning. There is a fair percentage of uranium in many of the rocks in the county and also in Orkney, but I guess if that was the case it would still be glowing, and anway I can't think of anything which would cause uranium to glow its natural state.

[canadagirl]

Stone with sulpher in it will burn, nicknamed brimstone. Is that where the name brims comes from?

[Whitewater]

Gleeber it is interesting that you have mentioned quarries, one of the other notes on this map mentions a slate quarry at Noss head where likenesses of beasts and flowers seem to be drawn on the stones with a yellow substance like gold leaf. Unfortunately this quarry has been filled in, according to the farmer at Noss a lot of horses used to fall into it in the old days

[gleeber]

Yes. |Ive seen loads of the gold leaf fossils. Jack Greens quarry at calder was full of them. Beautiful whole plants of seaweed and I never kept any. Some were 2 feet across and perfect.

[Whitewater]

Canadagirl, that could be the answer, it makes sense, it is possible that all the sulpher has gone now. It could indeed be related to the name brims.

[gollach]

It's not just a reference to peat then?

[theone]

Stone with sulpher in it will burn, nicknamed brimstone. Is that where the name brims comes from?

Good reasoning but I don't think it's correct.

Brims comes from the norse for "surf".

http://www.ordnancesurvey.co.uk/oswebsite/freefun/didyouknow/placenames/scandinavianglossary.html

[Dog-eared]

There be dragons in Ye Pentland Firth as well. :D

Copies of your map are available at the Scottish library, if anyone is interested. Details here http://maps.nls.uk/scotland/detail.cfm?id=168

[Whitewater]

Thats the very map, but I didn't get it through that route, a friend of mine has the original and is, at the moment, in negotiation to purchase some more. So as the say in the press, my source has to be protected.

[Kenn]

Was intrigued by this and went searching the web, there is oil shale in some of the sedimentary rocks within the county, the most notable being around Berriedale.
According to some of the sites I found it will burn the gases released from the sediementary rock leaving the actual soft stone almost unchanged.
I had to refer to several reports and items and tie the facts together so hence no link but a google search "Oil Shale in Caithness," will lead you to the same information.

[Whitewater]

Thanks Lizz, that sounds good, I first asked one of my old friends about this, he is a geologist and I took all the photographs for him when he done his thesis on the Geology of Caithness, but that was around 50years ago now, however he also said that the shale could cause it, but he suggested that it be posted on the org to see what other ideas were put forward from younger/fresher minds than ours. The suggestion about brimstone by Canadagirl also sounds good. But what intrigues us is the fact that we do not know anybody who has actually witnessed this phenomenon, but I must go away now and google "brimstone" to see what can be found.

Having returned to this post after googling brimstone and rock containing sulphur, I have now learned that they can self ignite.

[Kenn]

Have just been doing some more delving and it would seem that sulphur does occur in some jurassic and cretaceous sandstone although whether this is the case in Caithness I have not been able to determine so far.

[Whitewater]

There are sandstone layers in Caithness, you get a particularly good view of some of the layers if you travel in a small boat up the coast from Wick to John O' Groats.

[George Brims]

Stone with sulpher in it will burn, nicknamed brimstone. Is that where the name brims comes from?

Definitely not.

[canadagirl]

Oops! Was thinking place names rather than people names. No offense intended. :confused

[George Brims]

None taken. At least you didn't spell it with two "M"s like half the Christmas cards this year.

[Dog-eared]

Most of the place names up here are Norse in origin, or derivatives.
IE Cape Wrath does not mean a stormy Cape. Its name was Hvarf - Norse for "turning point".

[Whitewater]

Just want to say thank you to all who helped with my query before this thread goes to the org burial ground. Lots of good and interesting answers.