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Monday, 28 September 2015

A Long History of Rhosyfelin (4th version)


 

I have revised this document to take account of the latest information.  It's essentially a guide to what happened in the Ice Age, with a simple explanation how the regional chronology is represented at this site.   The more promotion there is for the quarry idea, the less convincing it becomes.  If you go to Craig Rhosyfelin "cold" and with no preconceived notions fixed in your head, and ask yourself what you are looking at, what you find is a rather beautiful craggy rock in a wooded valley, with a long history of landscape evolution and an interesting set of Quaternary sediments.  And signs of occasional settlement by hunters or travellers.  End of story.

A Long History of Rhosyfelin (4th version) 


This is an informal explanation of the history of landscape evolution, and sediment accumulation, at Craig Rhosyfelin in North Pembrokeshire. The site is claimed by archaeologists to be a Neolithic bluestone quarry, but that is not supported by the evidence on the ground.

30 comments:

  1. So the rhyolite orthostat/picnic table just 'fell off'? Brilliant. How long did it take you to come to that conclusion?

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  2. And to think I doubted you Brian.

    I'm glad that's all wrapped up.

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  3. Excellent summary of your position Brian and several critical questions that will need to be answered whenever the Emperor eventually appears in Public with his new cloth of woven data.

    I am puzzled why the picnic table appears to be horizontal - perhaps I'll take a spirit level next time I visit. Of course this is perhaps a fortunate coincidence for the picknickers - a gift of nature in a manner of speaking.

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  6. It isn't horizontal, Chris. It is slightly sloping. Still handy as a picnic table though.....

    Evergreen -- always pleased to help. Should it have taken me longer?

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  7. Brian, possibly. Given the mention on this blog a while ago about the charcoal found underneath it, I assume you are happy to say that it 'fell off' at some point in the EBA?

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  8. Is it likely that there is a trail of bluestones going south-east? Did anybody check this out I wonder - so the stones at Glandy Cross or Lampeter Velfry, did they ever get provenanced to Goedog or Rhosyfelin? Anybody ever check out the valley of the Taf?

    Last time I was in Laugharne I noticed several stones that looked like they could have come straight from Prescelli - but then what do I know.

    The rest of the route is likely under water these days.



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  9. What's the problem? Rockfalls are continuing to this day -- this big block was embedded in slope deposits, just like many others. The fall in question could have been Bronze Age, Iron Age or even later.

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  10. Chris -- this is all quite well known from the work of JC Griffiths. See this post:
    http://brian-mountainman.blogspot.co.uk/2010/04/pembrokeshire-erratic-routes.html

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  11. Looks like I am right about the Taf valley.

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  12. Well, you are right in thinking there could be Preseli erratics there. Could be dolerites, rhyolites and volcanic ashes -- whatever was entrained could have ended up in the area around the Taf / Tywi estuary and indeed out to sea from that point on.....

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  13. Brian, I will certainly very soon take a look at the post on the work of JC Griffiths you referred to at 21.18 this evening.

    Would you be good enough to tell us a little about JC Griffiths. With that surname I guess he may be a Welshman. I haven't heard of him before....

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  14. I am pleased to hear Chris mention Glandy Cross, one area in the Preselis that I have visited and walked parts of, including as it does Meini Gwyr.

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  15. Evergreen with a cold28 September 2015 at 22:13

    Brian, I haven't visited Rhosyfelin and I have a very basic knowledge of geology, so I assume from 'Whats the problem?' and 'rockfalls continue to this day' that there are other blocks in the ground there of the same size?

    Forgive me if you've dealt with this one before but i've recently been reading a report about a circle constructed around a glacial erratic and the (not unattractive) little thing is scratched all over from it's icy journey. Why is it that none of the undressed SH Bluestones bear such marks?

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  16. Evergreen -- may you recover quickly from your cold and enjoy this gorgeous autumnal weather! The big stone is the biggest one exposed in the dig-- but I suspect there are others which are equally large embedded in the sediments (and exposed at the surface) further up the little valley. I have shown some photos of some of them. The diggers chose not to extend the dig in that direction.

    Striations are only observed on the surface of erratics if a certain number of physical laws are obeyed. Fine-grained sediments like shales and mudstones tend to striate easily, whereas coarse-grained rocks like conglomerates, ashes, gritstones and gabbros tend not to preserve scratches. Then the tools have to be harder, and sharp-edged, and have to be pressed with sufficient pressure onto the surface of the erratics in question. If conditions on the glacier bed are wet or fluid, stones will simply be pressed downwards rather than scratched. In other circumstances, if the bed is frozen, there will be little abrasion going on. Where shearing is happening on the bed, even quite soft stones may be carried up into the glacier without much contact with other stones, and abrasion can be avoided in that way. Glacier beds are immensely complex systems which are still imperfectly understood, largely because they are so difficult to observe.

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  17. Tony -- I have cited the work of JC Griffiths several times before. Put "Griffiths" into the search box. His 1940 thesis marked a great advance and would have been more influential but for the War. He built on the work of the Geol Survey people including Jones, Strahan, Cantrill, Dixon and (the great man himself!) Herbert Thomas.

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  18. “ We know that stones have been taken from here by local farmers (and maybe by the chapel-builders of Felindre Farchog) but their "quarrying" has been very opportunistic, and I reckon that pillar-shaped rocks have been taken from here and there on the accessible part of the crag adjacent to the col or old drover's route, “

    I did ask about this earlier , maybe it got missed .
    If you cant’ identify the opportunism / “quarrying” of modern farmers , why should you expect to be capable of identifying prehistoric opportunism /”quarrying” ?
    If you can’t recognise either periods opportunism/”quarrying “ how can you say that it didn’t take place ?

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  19. We know that stones have been taken in historical time because there are written records of that. We cannot discount people picking up rocks at any stage and moving them from A to B if that's where they wanted to use them. What I have problems with is all these imaginary engineering features (the list gets longer by the lecture)!

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  20. Evergreen

    On the contrary, according to leading geologist of Wiltshire's stones, Isobel Geddes, there are discernible striations on some of the Stonehenge bluestones. I have quoted from "Hidden Depths: Wiltshire's Geology & Landscapes", Ex Libris Press, Bradford on Avon, 2000. I have mentioned this during the past year on Posts.

    "A few have been striated (i.e. scratched) by ice movement (although this could have happened in Wales).

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  21. Luckily we have these records and there were probably slightly less trustworthy ethnographic reports too ,and there is always the possibility that it is all nonsense ,but we'll ignore that , it seems perfectly feasible and likely .
    The point is , some geomorphologists who claim that there is no evidence for the removal of rocks were no more capable of recognising where these recent removals took place , how can they be expected to recognise much earlier removals or suggest that they didn’t take place ?

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  22. With respect to Griffiths as mentioned by Brian above and on previous posts; also Chris's mentions of the possibility of a trail of erratic bluestones trailing SE hypothetically, at least, taking in Glandy Cross prehistoric complex, the river Taf and maybe down to Laugharne to what is now the (politically - incorrectly named) Bristol Channel, I note there is/was the possibility that at Llandissilio [NGR SN119215 126212 3.5 miles south of Glandy Cross, there may be a cursus monument.
    This was revealed by aerial photography, was discovered relatively recently, and hasn't been confirmed by excavation. NP Figgis mentions it in his Prehistoric Preseli (revised 2010). A double line of cropmarks runs in an E - W direction under Llandisssilio village. Figgis says with caution "the position of the crop - mark, near the river [Taf] and in the same general area as both a henge and axe - making activities [Neolithic], is typical of
    known cursus monuments, and bodes well for its future verification".

    Anyone know any more about this possible early Neolithic Cursus monument? Geo?

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  23. Not me Tony .

    Just had a look and there is a splendid confusion .

    “A parallel cropmark of two lines running roughly northwest-southeast “ Archwilio
    “Cropmark features thought to represent a single linear complex running roughly 730m ENE along a ridge-line,” Coflein
    I think Archwilio have got it right .

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  24. Tony, Coflein :

    Cropmark features thought to represent a single linear complex running roughly 730m ENE along a ridge-line, from the given NGR (the position of an OS trig. pillar) to SN11802150: the main feature of the complex is a 'trackway' up to 25m wide, about which are various pit/posthole alignments, two stones being depicted by OS County series (Pembroke. XXIV.6 1889) towards the western end: the complex has been interpreted as a cursus monument, possibly connecting with the cropmark complex at Pen-cnwc (Nprn402413), some 500m to the north-west, across a sometimes steep-sided valley, producing a linear compex of roughly 1,450m overall extent.

    Sources: James 1989 (AW 29), 31-4;
    Gibson 1999 (in Barclay & Harding (eds.) 'Pathways & Ceremonies'), 130-140.

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  25. Thank you, Evergreen & Geo.

    It would be very interesting to know whether, for example, the Dyfed Archaeological Trust [or whatever their correct nomenclature is] thinks about this possible Cursus Monument.

    Also, Professor Tim Darvill, these days based at Bournemouth University: as we know, he has been very active one way or the other in Pembrokeshire/ SW Wales for at least 2 decades, and is a leading specialist in Neolithic Britain. Perhaps he would like the challenge. One of his colleagues at Bournemouth is Kate Welham, one of the inner circle of the Stonehenge Riverside Project and also the MPP work recently at Rhosyfelin, etc. Kate is a geophysics, etc, specialist.

    So the "Two Tribes" beloved by Brian may reappear, but this time with Kate having a foot in both the MPP & TD tribal camps.



    WHO, if anyone, will seek to take matters further and perhaps do some very state of the art investigations with investigations of what lies beneath the earth 9and also, beneath the village!) perhaps similar to what Historic England [previously known as English Heritage] has been doing in the Greater Stonehenge Landscape, as evidenced by their recent large book.

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  26. Apologies Geo, your post hadn't been published when I sent mine.

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  27. If in the unlikely event that it is a post defined cursus ,then being rare outwith Scotland it might be of greater interest than just another unexcavated cursus or trackway .
    One person who is interetsed in timber monuments and has excavated quite a few sites in Wales is Alex Gibson . He views the site as a trackway and he would be seem a possible candidate if it was ever excavated ,if only a couple of pits to see if they had held posts and retrieve possible dates to see if it was as early the Scottish examples .

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  28. Nae prob EG , I don't know what day it is never mind the time .

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  29. Agree with your comment about Alex Gibson and in relation to other sites further east in Wales, Geo.Folk may easily get hold of at least one of A.G's books via their rapidly - disappearing public library: use it or lose it!!!

    Incidentally, I think we get comments on here from someone signing in as "A.G".

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