The location of the Ramson Cliff erratic -- which was found at about 85m OD but which has now been moved to the lower edge of the field. Beware -- it is sometimes called the Baggy Point Upper Erratic............
A REVIEW OF THE RAMSON CLIFF ERRATIC: EVIDENCE OF HIGH-LEVEL ICE FLOW?
Tim Daw, Rob Ixer and Paul Madgett
Quaternary Newsletter 167, Feb 2026, pp 13-19
I suspect that the prime author is Tim Daw, and that Rob Ixer and Paul Madgett have contributed specific detailed segments of the text or provided information.
It's strange because the article doesn't seem to know what it wants to say. It strikes me as an article in need of some evidence. After an introduction flagging up the uniqueness of the boulder (which we might question), the authors describe its location after being moved around a bit by the local farmer, and then they describe its petrography. This is interesting, and provides us with much more detail than we had before -- but the conclusion (namely that the erratic has probably come from the Cornubian rocks exposed to the south) needs to be treated with caution. There are at least two reasons for this:
(a) we would be basing a powerful weight of evidence on one small sliver of rock used for a thin section, representing maybe 0.01%of the bulk of a 700 kg boulder, with a rock type that is notoriously variable. It appears that epidiorites (the rock type in this case) are renowned for being "patchy". Metamorphism is rarely uniform across a large block. A patch in one corner that looks Cornubian doesn't rule out another Scottish-style patch 20 cm away. There has been no new sampling -- the thin section slide is the same as that examined over 50 years ago.
(b) as far as the provenancing evidence is concerned, there is too much telling and not enough showing. We don't get to see the slide in question, or those with which it has been compared. Ixer is effectively telling us to believe what he thinks -- "I'm the expert, and you need to believe what I say to you......" His evidence is almost entirely subjective visual matching based on decades of experience looking at stones. Some stones. There are lots of others that he hasn't looked at. When he says it's a "match" for rocks outcropping on or near Dartmoor, he is making a visual call that a layperson—or even a general geologist—cannot easily verify without access to the same "library" of thousands of thin sections. So scepticism is entirely in order.
Zoned garnets or specific biotites: Scottish Dalradian rocks often contain complexly zoned garnets or high-Ti biotites formed during the intense, multi-stage Caledonian Orogeny. In contrast, Cornubian greenstones were altered by a single, later heating event from granite intrusions. If a thin section from the erratic showed these "polyphase" metamorphic crystals, the Cornubian theory would collapse.
High-salinity fluid inclusions: The Scottish Dalradian is "ubiquitous" in high-salinity and volatile-rich fluid inclusions that are characteristic of its specific regional metamorphism.
Trace element ratios: Geochemical analysis using the ratios of Lanthanum (La), Thorium (Th), and Scandium (Sc) can distinguish between different tectonic origins for basic rocks. A Scottish rock would likely show a different "arc-like" trace element signature compared to the intra-plate signature of South Devon greenstones.
All that having been said, I am profoundly sceptical that you can actually do precise or spot provenancing on anything, since we do not have a detailed or comprehensive knowledge either of the erratics we are seeking to find homes for, or of the geographical occurrences of all possible sources.
(The problem is exactly the same as that which confronts us at Craig Rhosyfelin, Carn Goedog or any of the other UK locations that are deemed by Ixer and others to be Neolithic monolith quarries.)
Anyway, interesting work which moves us forward, and I am sure we will see more of it!
Following a rather sterile and futile "history of the stone" which involves a mention of WW2 Luftwaffe air photos (I kid you not), the authors move on to a discussion of other erratics in the Baggy Point - Croyde -Barnstaple area, and say of the erratics in the Fremington deposits: "they are not inconsistent with local areas, such as the Dartmoor Aureole and so are not uncontested evidence of Irish Sea glacial intrusion." That is an absurd statement, but it is followed by another which destroys any pretence that this is a serious scientific article: ".......the Ramson Cliff boulder is unique as a claimed example of a high-level glacial erratic in the area; all other documented glacial erratics were found below 30 metres OD." That is a lie. There are around 20 other erratics, described by Paul Berry and Paul Madgett in the literature, and even mentioned by Daw in other posts on his blog. They occur, for example, at altitudes of 45m and 60m. They are smaller than the Ramson Cliff erratic, and have clearly been moved about since they were found, but they are no less significant than the thousands of small erratic clasts that I have found in the fields and stone walls of Pembrokeshire. It is just that here lead author Tim Daw chooses to ignore them because they are inconvenient.
From here on it is all downhill, with a discussion of mechanisms by which the Ramson Cliff boulder might have been emplaced. Once again, the discussion about ice-rafted boulders is spoiled by a complete failure to assess the isostatic - eustatic interactions that might have applied at times when ice-rafting might have operated in the Bristol Channel. The preference of the authors (or at least two of them!) is for the human transport of the boulder, regardless of the complete lack of evidence that might support that. It's all very vague, and full of speculations and assertions as substitutes for facts. The authors round off with this:
In other words, we contest the other erratics or choose to ignore them -- thefore they do not exist.
Oh dear oh dear.......
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