tiompan Dec 5, 2013 11:07

Cooee .

thesweetcheat Dec 5, 2013 13:50

I'd love to know the geology behind that stone.

tiompan Dec 5, 2013 19:19

Quartzite ? I can't remember ever seeing anything like that though .

thesweetcheat Dec 5, 2013 20:31

Lovely isn't it?

tiompan Dec 5, 2013 20:38

yes , and puzzling .

thesweetcheat Dec 5, 2013 21:00

wow, I've found something that puzzles you!

tiompan Dec 5, 2013 21:44

Have contacted a sculptor and a geologist , hopefully we'll learn something .

thesweetcheat Dec 5, 2013 22:00

Brilliant, thanks George.

tiompan Dec 6, 2013 00:32

Alken , if you have them could you send me the uncompressed pics of the stone please . ?

thesweetcheat Dec 6, 2013 08:38

Yes, sure (will be this evening).

tiompan Dec 6, 2013 16:39

"It's a decorticated stem from an arborescent lycophytes (club moss) almost certainly Lepidodendron. As the plant grew the "bark" with the photosynthetic leaf bases was shed from from the lower part of the main stem or trunk, leaving a surface with this sort of diamond-shaped patterning. Lycophyte stems in this type of preservation are sometimes given the taxonomic name Knorria, but such names are not very meaningful botanically. "

from Head of Botany at Nat Mus Wales via geology/petrology .

thesweetcheat Dec 6, 2013 20:41

That's terrific, made a lovely stone even lovelier.

I wonder if it was selected for the pattern? Difficult to imagine it being overlooked.

tiompan Dec 6, 2013 21:29

Everyone has commented on how unusual it is . I have never seen that sort of thing on quartzite .

Almost certainly chosen for that quality , just like the Stoney Littleton ammonite etc ,one of the stones at the cairn is pretty striking too.

thelonious Dec 6, 2013 22:37

What an interesting and lovely stone. Thanks to the both of you for posting the photo and the info. Lots to think about. Stuff like this is why TMA is great.

Llorfa