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Wednesday, 21 December 2011

Craig Rhosyfelin sampling points

For those who might not have access to the original paper, I'm sure that Rob and Richard will not mind me sharing this image which shows the Craig Rhosyfelin sampling points which they used in their identifications of the foliated rhyolites:

Full reference:

“Craig Rhos-Y-Felin, Pont Saeson is the dominant source of the Stonehenge rhyolitic ‘debitage’”, by RA Ixer & RE Bevins, Archaeology in Wales 50 (2011), 21–31


Anonymous said...

I think that the true number of samples from Crag Rhos-y-felin now is closer to 30 including one provided by your noble self Brian (you and MPP lie alongside each other within the acknowledgements-strange bed-fellows indeed).
Much more and the poor Crags will have been lost.

BRIAN JOHN said...

Yes, and noticed the acknowledgement of my sample collecting activities -- and many thanks for that!

But I am interested in this apparent "grain" or alignment which I commented on in an earlier post. Can we see a map of all the sampling points in the Brynberian - Crosswell - Felinygigfran district? I can see that you have changes in rock structure as you move along a line NW-SE -- but is this particular foliated rhyolite restricted to just this location on a NE-SW line, or could the "unique" rock type be in a long strip, extending for several miles?

Anonymous said...

No it is restricted to Rhos-y-felin otherwise we would have listed all the possible sites.
I have explained that my attitude to the data and what they mean is benign indifference.
The sampling sites for the greater Pont Saeson area are on on 6mile to the inch base maps.
Brian we are not amateurs and the truth is that we have not replied on this question or similar ones in detail to spare your blushes.
Your geological interpretation of the 'grain' is rather a simple one and has no ground truth.
There are four pieces of bluestone all spotted dolerite from Silbury Hill. Three only recently found. Fully described and discussed in the forthcoming Silbury Hill memoir.
Can we have a year without black arts/fellow-travelling hired-hand running-dog lackies and just do a bit of science (and lots of classical wimsy).
A hint for us all, many helpful and brilliant suggestions from amateurs have been fully explored, before the light bulb goes on. For example continued sampling at SH.
Sh is a small pond and all we tadpoles hoping for eventual princedom know each other and often work together
speedy croak croak

BRIAN JOHN said...

Don't worry -- I'm not going to blush. I'm just asking politely where your 30 sampling points are. I know you guys are professionals, but I have refereed enough glaciology and geomorphology papers in my time to know that professionals are just as likely to draw unwise conclusions on the basis of flawed evidence as anybody else.

Anonymous said...

The 30 are JUST Rhosyfelin itself
the myriad sampling sites around it are in addition to that-none are rhyolite.
Those sites are data for the future so not to be released here. A refereed journal is the correct first place.
Glad you liked the Nat Geog.write-up
It was the result of 40 mins transatlantic phone call on Wednesday that I had- with the original text corrected by Richard and I (and the removal of some of my more slanderous quotations.
I have pointed out to Mr Mosher that in English the past participle of the verb to bet is bet not betted!! He has promised to tell his editor.
That I would no more have said that than discuss the transport mechanism for the bluestones and believe me I have been asked that 15/20 times this week usually as people sign off.

You provoke me!!! so as you well know every real geologist refers to the Pleistocene as 'gardening'. nuff said.
I am sure glacial people have similar thoughts about geographers.

Speedy he who puts the bet in better!

BRIAN JOHN said...

...... not to mention what geomorphologists say about geologists!