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Monday, 9 May 2011

Why are the geologists so scared?

Press reports of the new geology work relating to the geology of the bluestones  -- and the fragments -- found at Stonehenge keep on appearing.  Below is an article published on a New Zealand web site and reproduced in the UK.  As usual, the report is full of garbled nonsense -- but what interests me in particular is the manner in which the geologists involved in the new work (Richard Bevins and Nick Pearce) seem to be scared to death of using the G word.  Glacier.  Nice little word, with which most geologists should be familiar.  One hopes that when they were young, they did some studies on earth surface processes, including glacial ones. This article, like 99% of others on this topic, gets its knickers in a twist by insisting that, whatever the evidence on the ground might show, the Stonehenge bluestones were carried from somewhere -- anywhere -- to Stonehenge by heroic Neolithic tribesmen, come hell or high water.......... by some ever more convoluted route, if the simplest one presents difficulties.  Quote:

In a picturesque and quiet corner of West Wales called Pont Saeson is a rocky outcrop that looks like any other in this mountainous country.  But thousands of years ago it provided the building blocks for the ancient structure of Stonehenge that still captivates people today.  Pearce says their research has located the exact spot the stones came from.  “It pins them down to place where nobody has really considered they came from before; on the north side of the Preseli Hills in North  Pembrokeshire and not localities on the top of the Preselis.”  The unearthing of the stone’s origins also challenges the theories on how the builders of Stonehenge transported their materials to Salisbury Plain.  “It was always thought they were transported by humans south down towards the Bristol Channel and put onto rafts at Milford Haven. Well this location changes that perspective,” Bevins says.

Have the geologists joined the archaeologists who are fully signed up to the mantra "I don't believe it, even if it's true" regarding the glacial transport theory?  It would appear so.  That's a pity, and I suggest that their denial opens them to the accusation of being involved in good technology but bad science.  Good science considers options and alternatives, articulates them and weighs them prior to making suggestions based on the balance of probabilities.  What are the geologists so scared of?  WHO are they so scared of? 

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Mystery origins of Stonehenge unravelling
9 05 2011
Stonehenge is an ancient site which dominates Salisbury Plain in the south west of England. Much of where the stones came from and how they were moved is still an enigma.

Built around 3100 BC, the origins and purpose remains the subject of much debate around the world.

At the National Museum of Wales in Cardiff some detective work is taking place that could help solve this historical conundrum.

With precision and patience Dr. Richard Bevins is examining a minute piece of stone that is part of a 5000-year-old mystery.
Under his microscope is a sample taken from Stonehenge.

Bevins says the whereabouts of some of the stones is already known.

“Stonehenge comprises an outer circle, an inner circle and an inner horseshoe. The outer circle, which are the very big stones are actually local to the Stonehenge area, to Salisbury Plain.”

In the 1920s scientists traced the origins of the remaining stones, known as Bluestones, to an unspecified part of the Preseli Hills in Pembrokeshire, West Wales.

This is 240km from Stonehenge. It remains unclear how an ancient civilisation would have transported such heavy stones such a huge distance.

Bevins says: “These stones that form the inner circle and the inner horseshoe, the Bluestones, they still weigh two to three tons so they’re substantial pieces of rock to be moving around the countryside, if it was humans.”

A unique discovery is now fuelling further debate about how the architects of Stonehenge moved their building materials from Wales to the south west of England.

Dr. Bevins and a team of scientists have matched stone samples from Stonehenge with ones taken from the Preseli Hills and uncovered their precise origin.

They have done it by using new technologies by analysing and comparing their mineral content.

“We got a good match in terms of what they looked like in hand specimen and down the microscope,” says Bevins. “But we wanted to go one stage further, we wanted to have a diagnostic technique, we wanted some data.”

Still in Wales, at the University of Aberystwyth, geochemist Dr Nick Pearce was tasked with analysing the zircon crystals that are embedded in the stone samples.

He pioneered a technique that uses a laser to vaporise the crystals so that their chemical make up can be scrutinised.

Pearce explains how the technique works.

“We get hold of the samples as thin sections. We’ve identified in those where the grains of zircon are that we want to analyse and then we put those samples into the glazer abrasion ISO PMS system, fire a very powerful laser on top of the samples, on the individual grains within the sample. The vapour gets transported then into a mass spectrometer and we analyse the components of that mineral grain.”

By matching the chemical finger prints of their stone samples they have proven the origin of stones used to build parts of Stonehenge.

In a picturesque and quiet corner of West Wales called Pont Saesnon is a rocky outcrop that looks like any other in this mountainous country.

But thousands of years ago it provided the building blocks for the ancient structure of Stonehenge that still captivates people today.

Pearce says their research has located the exact spot the stones came from.

“It pins them down to place where nobody has really considered they came from before; on the north side of the Preseli Hills in North  Pembrokeshire and not localities on the top of the Presellis.”

The unearthing of the stone’s origins also challenges the theories on how the builders of Stonehenge transported their materials to Salisbury Plain.

“It was always thought they were transported by humans south down towards the Bristol Channel and put onto rafts at Milford Haven. Well this location changes that perspective,” Bevins says.

It’s now thought the stones took an alternative route and travelled 16km west to the natural harbours that dot the Welsh coastline then shipped to their final resting place on Salisbury Plain, in England.

This theory now needs to be tested by archaeologists.

These new discoveries bring people who are fascinated with Stonehenge one step closer to unlocking its mysteries.

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More information: http://www.3news.co.nz/
Sponsored by ‘The Stonehenge Tour Company’ www.StonehengeTours.com

4 comments:

  1. Tony Hinchliffe9 May 2011 at 17:52

    To paraphrase the great Zombies [still touring the country, folks!] '60s song, "I Don't Believe In Miracles", it would seem that the answer to your question, Brian, 'Why are the geologists so scared?' is as follows:-

    The collective inward cry from the self-proclaimed Bluestone Connoisseurs (be they geologists or archaeologists.........but of course, geomorphologists are for some reason excluded from this particular intellectual party) is:-

    "I Don't Believe In Glaciers" !*!"

    (certainly not in this particular geographical context), because, if I even admit to the possibility of their involvement in the bluestone transportation scenario, then I have to cease insisting on the rock-solid factual accuracy, come hell or high water, of humans lugging the stones over vast distances.

    I shall continue to justify "The Old, Old Story" just because it "still captivates people today" (direct quote from N.Z. article!)

    In a nutshell, these Guys were pretty much just like us, except they had one hundred times our bottle and were, well.....pretty magic! Besides, it makes a great story, rivalling the building of The Pyramids!!! And, dash it all, we are British, and anything they can do............

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  2. Tony Hinchliffe9 May 2011 at 18:03

    ALTERNATIVELY, of course, it could well be the case that the Geologists are just too respectful and obsequious towards the revered and wise archaeologists, with their long-standing, written-in-stone (or is that sand?) versions of events.

    Come on now, you Geologists, stand up and be counted! After all, you ARE Geologists, so stick to the scientific facts about the rocks, and don't get led astray in your conclusions by the archaeological stories which owe much less to Science.

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  3. Brian,

    I sense and sympathize with your frustration that glacier transport of the bluestones is not seriously considered by all these scientists!

    There are, I think, two explanations for this. Either these geologists 'toe the line' of what is 'politically correct' to promote. Or, they don't see clear and convincing evidence for your glacier transport theory.

    They may be looking at the evidence of where the 'glacier limits' are from the last glaciation and don't find these extending to Salisbury Plain. Of course, you would argue that the bluestones came to Salisbury Plain at a previous time of glaciation dating back to 400,000 BC. But there are serious issues with that and much has to be taken on faith and conviction.

    Don't get me wrong! I am in agreement with you that ice played a prominent role in the transport of the bluestones. But it wasn't exclusively 'glacier ice' – which would leave a trail that is just not there.

    Rather, also involved in the transport was 'local ice', formed when vast bodies of water after the 'great melt' froze solid during the 'deep freeze'. There would not be any 'trail of evidence' left behind by such ice. And the physical characteristics would be different from glacier ice, as you previously stated. That is what my theory argues.

    Constantinos

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  4. Actually I sympathise with these guys to some degree. It may be that they do find difficulty with the "glacier transport" theory because they don't see long erratic fans or trails, and because they don't see evidence of moraines on Salisbury Plain. Fair enough. But they could at least acknowledge that many serious field scientists (including Kellaway, Williams-Thorpe, Aubrey Burl and myself) have thought about this and have nonetheless come to the view that there are far fewer problems with the glacial transport theory than there are with the human transport one. Just a teeny weeny mention of the glacial theory would be nice......

    The other problem they have is that there are two geomorphologists who have pontificated on Stonehenge and the bluestones. James Scourse and Chris Green wrote chapters in the big 1997 tome called "Science and Stonehenge" -- and for better or for worse, the archaeology establishment considers those two to be THE experts in glacial matters. With all due respect to both of them, I suspect they were chosen to write those chapters because their views were already known to be bang in tune with those of the archaeological establishment. He who pays the piper calls the tune.....

    And again, giving them due respect as careful field workers, neither of them is a glacial geomorphologist, let alone a glaciologist. So why should their views be trusted as "the last word" in this debate? Plain crazy. And I would be equally appalled if my views were accepted as the "last word" too. That's not how science works......

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