Thanks to Rob for providing a link to this interesting podcast. It's good to hear things explained carefully and clearly, after all that hype. There are just a couple of things on which Rob might have been more careful. There are not 80 bluestones at Stonehenge -- there are around 43, including both standing stones and stumps. And the natural rock at Rhosyfelin does not naturally break up into long columns or orthostats. It breaks up for the most part into smallish angular fragments as seen in the pic above -- with occasional larger blocks.
www.cbc.ca/quirks
Sourcing Stonehenge
It has long been known that many of the so called "bluestones" that are part of the prehistoric monument Stonehenge, come from Wales. The bluestones, which are either buried or just above ground, are found in a ring inside the iconic standing stones. Now Dr. Robert Ixer, a geologist from The University of Leicester has been able to pinpoint the source of a subset of these bluestones. By analyzing rock flakes from these stones at Stonehenge and comparing them to samples from a large region of Wales, he's found a match to a specific outcrop in Pont Saeson in North Pembrokeshire, Wales. This means these bluestones traveled hundreds of kilometres from Wales to the Salisbury Plain, site of Stonehenge. Just how this happened is one of the enduring mysteries of Stonehenge.
Related Links
Dr. Ixer's paper is not available online. It was published in Archaeology in Wales 50, by the Council for British Archeology
National Museum of Wales press release
BBC News story
National Geographic article
22 comments:
Nice listen. Rob sounds a total geek and judging from his wife's statements with a family preference for the human transport theory. I suppose myself that the likely route for Rhos-y-felin stones would have been down to the sea at Newport rather than over the Prescelly tops but ...
He has quarrying on the Rhos-y-felin spot in his mind, if not by glaciers then by man. From the little I know, I suspect a giant erratic was picked up and moved to Stonehenge and quarried there. As Brian says, natural quarrying into orthostats at Rhos-y-felin would have created quite a mess.
I don't know we will ever know for sure. It does seem likely that without the human transport theory Rob would never have put so much work into tracking the provenance and we should be grateful for that.
The giant erratic theory is a lot easier to visualize for the layman, has equal probability of being true, and speaks much more vibrantly to the imagination - at least in my opinion.
Quoting directly from the Sourcing Stonehenge podcast report in this post,
“The bluestones, which are either buried or just above ground, are found in a ring inside the iconic standing stones. Now Dr. Robert Ixer, a geologist from The University of Leicester has been able to pinpoint the source of a subset of these bluestones. By analyzing rock flakes from these stones at Stonehenge and comparing them to samples from a large region of Wales, he's found a match to a specific outcrop in Pont Saeson in North Pembrokeshire, Wales.”
It is implied in this quote the bluestone flakes analyzed and sourced to Rhosyfelin outcrop are chips from bluestone orthostats in the bluestone circle. This is clearly misleading since this is not scientifically proven.
In my view, the greater question here is the sourcing of these foliated rhyolite fragments to stones at Stonehenge. Not the provenance of these fragments to the Rhosyfelin outcrop. As important and interesting as this is. Dr Ixer does not need to travel to Wales to look for the answer. He can just examine the stones of Stonehenge for a match. And if no match is found with any of the standing, laying or buried megaliths in Stonehenge, than how these foliated rhyolite fragments got to Stonehenge becomes possibly the key to answering the transport question.
Kostas
Where are the stones at Stonehenge for these Rhosyfelin fragments? And why Dr Ixer does not demand these stones be found?
Is Science used to support the views of archeologists?
Chris , I can't believe Rob has a preference for any of the three sides .
Anon -- to a degree, as I have said before, we do have a scenario in which "geology is working in the service of archaeology." that's a pity, because it places constraints on the geologists that we wish were not there.
But don't blame Rob for the lack of decent geological work on the stones and stumps at Stonehenge -- he can plead all he likes, but in the end it is EH that decides what work is done and what proposals are blocked.
Brian,
You are being too easy on Dr Ixer. If he agrees to source the rhyolite fragments in Wales, he can certainly demand to source these fragments in Stonehenge. Science expects that much of him. Otherwise he's just a hired gun shooting down competing theories and perpetuating myths.
Dear Chris Johnson,
Having just read your post regarding Doctor Ixer I wonder if you are in any position to label him a 'total geek' or even to judge his wife's statements. Do you know him and his wife that well?
At least he knows his subject and has produced something original relating to Stonehenge, which sadly you have yet to do on this blog.
Disappointing behaviour on your part.
Cores were taken for the OU project (OWT). I suppose these are still in a shoebox somewhere?
Geo - I think we all have preferences and that does not matter as long as we maintain objectivity - no reason to think Ixer is letting preference affect his science.
Dear Bob the Builder,
Fair comment. I'll be more careful in future.
For the record, "total geek" is a term of endearment in my circles so no disrespect was meant and I am sorry that my remark was taken badly.
My take too, Chris. I don't think you were being offensive or condescending -- I think I might be quite pleased to be called a geek!
Chris ,I said I didn't think Rob had any preferences .
Dear Brian and Chris,
Just for the record and to end this thread, Wiki's definition of 'Geek' is ------ "a peculiar or otherwise dislikable person, esp(ecially) one who is perceived to be overly intelligent".
Make of that what you will.
Betty -- oh dear, I'd better revise my opinion about that word. Must admit I have never looked it up, but have always though of a geek as a lovable sort of person who is totally absorbed in his / her work. Well well, we live and learn. Anyway, I'm sure Chris meant no offence...
I believe Geek is probably less pejorative than swot ,it is usually taken as applying to someone who is a bit keen on their subject to the exclusion of paying attention to dull things like matching socks etc .
GEEKS & GEAKES: PROVENANCE??
I attended a Stonehenge Seminar at Devizes where the Great and the Good, mostly from the Stonehenge Riverside Project, eleven in all from memory, gave us talks.
Rob Ixer gave a profoundly specialist account of his geological analyses, inevitably rather hard to grasp. I spoke to him during the lunch break, and found him eminently likeable, pleasant and polite.
I did not find Chris' use of the expression 'total geek' on this thread, read in its context, at all disrespectful.
Geeks are essentially specialists and not necessarily dislikeable (despite what wikipaedia may have you believe -best use a decent Dictionary) However, it is a constant human failing to pick on someone who is unusual or different to some degree! Impressionists make a living out of impersonating all manner of so-called 'geeks', check Rory Bremner's cast list!!
Football lovers everywhere will recognise John Motson as very loveable geek.
For what it's worth, easily my favourite geek is Helen Geake of Time Team; she is (inevitably I suppose) a specialist (in Anglo-Saxon studies).
Today Dr Alice Roberts tweeted about www.geekmanifesto.wordpress.com This is a new blog by Mark Henderson, Science Editor of our favorite newspaper - The Times. Science Matters is the theme. If Mark has his way, the G word will be on the agenda during the next election and meanwhile he is writing a book in praise of Geekdom.
There are other G words that have changed their meaning radically over time. The original meaning of my G word describes circus performers who bit the heads off chickens and live snakes. No this is not Dr Ixer, but Perhaps Mark has in mind to revive some of this ancient meaning in his political campaigning (smile).
Sorry to bring this up again, but Mark's manifesto will interest many and I found it too much of a coincidence.
Tony H
Interesting that you give a mention to Helen Geake of "Time Team": Brian's audience may be fascinated to learn that Helen is a cousin of the late, great, John E Geake, for whom the asteroid '9298 Geake' is named.
And I never objected to Mike Yarwood impersonating me - all good publicity for Astronomy.
PATRICK MOORE
Tony , a memorable night ,Jan Tomaszeswki is up there with Chaplin and Keaton .
GeoCur
A 'memorable night' for whom...... an Englishman or a Scot? I watched the England World Cup Victory in my Scottish uncle's hotel.......he refused to view it!!
I would have been happy to see Jan T. "up there" with Buster Keaton .......on the ledge of a skyscraper window!
Tony , let's just say I have a wee shrine dedicated to JT in the family chapel .
This world cup is an emotional memory for someone holding a Dutch passport. Can we move along quickly please?
Wikipaedia going black and thus unavailable the other day reminded me to say that, to my surprise, "The Artist Formerly Known as Patrick Moore", who blogged the other day on the thread, seems to have got his factoid about HELEN GEAKE of TIME TEAM quite correct!: it turns out Helen is, indeed, related to the late JOHN E GEAKE, for whom the Asteroid '9298 Geake' is named.
It must be true, for it says so in Helen Geake's Wikipaedia entry!!
Geeks are essentially intelligent enthusiasts: Brian has told us he has a Glacier named after him.
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