[John Mason]

Several UKww regulars know the Submerged Forest at Borth. But here's something new:

http://www.bbc.co.uk...-wales-17353470

This morning at low tide I visited the site with Dr Bates and we found a superb new human footprint. They are not sharp - think of prints made in boggy sections of hill-footpaths. Photographed this, the footprints of cattle, a post-hole, a burnt stone horizon, a large fallen oak cut for tree-ring analysis and so on. It's fascinating stuff though it takes a little while to get your eye in. Sadly, if it remains exposed like this, wave action will severely erode it, so it's vitally important that as much is recorded as possible now. It's aroused much local interest: they are well aware that sea-levels can and do change what with the submerged forest and the new sea-defences, countering the effects of future sea-level rise being one reason for the latter. Photos to follow in a day or three.

Cheers - John

[ldavidcooke]

Hey John,

Those are some terribly flat feet, not the feet of a hunter/gatherer. Looks to be an example of farming or within the last 8ky. Any C14 for dating done? Did not see any references wrt time frame...

[John Mason]

Dave: indeed they were clad feet,(apart from one of an estimated 4-year-old child - removed to the laboratory) from the Bronze Age, i.e. less than 4150 yrs BP. We have also found a lot of strong evidence for the same people working copper-mines in various parts of Wales. This was a busy part of the world, 4000 years ago!

Cheers - John

Edit - the basal peat on which the old forest stood is 6500 BP. That being late Neolithic, and at a time when the coast was some distance to the west.

[John Mason]

Here are a few photos:

1) lower peat-bed with burnt stone fragments embedded

2) sampling-trench with lower peat (with burnt stone fragments near top) overlain by salt-marsh clay with a thin upper peat on top

3) general view of the area with the footprints

4) human footprint: note that the peat has now hardened over the millennia so that boots hardly make the slightest impression

5) hoofprint - bovine

6) detail of salt-marsh clay with plant fragments

7) fallen oak, direction of fall SW-NE in common with the majority of fallen trees in this deposit indicative of prevailing SWerly storm winds at the time. The cutting was done in 1970 for tree-ring analysis and dating, with a second cut taken recently for the same purposes. The trees all grew in the lower peat, the base of which dates back to 6500 y BP.

Cheers - John

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[Dave Hancox]

Interesting stuff John.

[Flatlander]

A really interesting discovery - thanks for posting. Peat is great for preserving things - until they are uncovered!

The local raised mire had a trackway of similar age found - constructed with pine branches - but there is no knowing what kind of other archaeological evidence the peat mining companies discarded whilst strip mining was in progress.

www.thmcf.org/downloads/Trackway_talk_notes.pdf

This post has been edited by Tim Prosser: 18 March 2012 - 18:24

[ldavidcooke]

Hey John,

To me the most interesting is the idea of a hard bottomed clad foot. Most early versions were little more then hide sacks stuffed with fur.

It was not till between 3-5kya that grass weaved insoles started showing up in Europe. In South America the Andies mummified children did not show a hard soled foot covering even as late as 1200ya. (Many would suggest that is related to the ceremonial nature of their clothing.)

If we look at the Alps "Ice Man", whatever the name they call him now, clearly had woven grass soles. It really was not till tanned and toughened rawhide was widely available that a true "hard sole" shoe was created roughly 800-600ya, wood would not have worked for most hard surfaces. For one wood insoles would have worn the hide binding prematurely; as to others, a wood sole on a hard surface would either be too slippery or inflexible making walking long distances difficult. To see these examples you provided us with suggesting little arch, really should suggest that a different shodding of ones feet would be used based on the environment.

(IE: Wooden soles in the mucky mires of the Netherlands. Wonder if that style was not the reason for the lack of the usual arch we see in earlier examples. After all, just because we use different resources today does not mean an equivalent technique/application did not exist prior...)

[John Mason]

Difficult to know for sure, Dave: bear in mind that when these were made the substrate would have been pretty soft and gloopy!

Cheers - John

[ldavidcooke]

John Mason, on 20 March 2012 - 06:02, said:

Difficult to know for sure, Dave: bear in mind that when these were made the substrate would have been pretty soft and gloopy!

Cheers - John

Hey John,

Concur, if the peat being removed were for farming. My thoughts are where these prints were made mining dried peat and the oxen prints could be related to hauling of Winter/cooking fuel...

That there does not appear to be tracks where traces were drug or wheels would suggest a form of "Saddle Bag" due to a swampy terrain. These prints may have been made by early peat miners...,

I guess it depends on the direction of travel. Looking at your original image would not support that thought. Based on your personal observation, was the coincidence of prints suggestion random direction or do they suggest a similar direction, of travel...?

[John Mason]

Dave, more like an irregular hotch-potch. The way the guys see it, it was a case of occasionally sinking through other, now missing, layers above, just like one does when crossing a bog: ankle-deep for a couple of paces then up to your knees in the stuff, so that actual tracks would not tend to be that coherent. By the time this happened the area was likely a salt-marsh, so that the peat would be poor as a fuel. Many years ago after a storm when another patch got carved-up by the waves, a mate of mine living in Borth gathered a bucket of washed-up peats and dried them and tried them on his fire. Stank the bloody place out! They slowly turn to ash without helping out much heatwise, and the smell is of sulphur dioxide - perhaps early diagenetic iron sulphide has already formed in the stuff.

Cheers - John

[PK2]

Interesting John. Slightly O/T but do you know of any maps of Britain's coastline around then?

[John Mason]

I don't, and I don't think we know that well. This all occurred right close to the end of the steep part of the post-deglaciation sealevel-rise. Easy to go back to 9000 BP and say Cardigan Bay was land, but most of the subsequent remaining rapid rise was done by 6500 BP.

Cheers - John

[ldavidcooke]

Hey John,

Thanks for the clarification, kind of reminds me of playing 3D Chess. One track at a higher plane crossing a track at a lower plane...

Though we do need to keep in mind that 4kya the Ocean would still have been about 40 meters lower then present. With that the idea of a salt marsh is unlikely unless you have saline crystal in the minerals you have sampled...

By the same token if there were high levels of H2SO there should be low levels of iron as most Fe/FeO would have been consumed unless the bacterium were anarobic leading to high FeSO traces in the samples that were made. Have you seen a Spectro-Analysis of the samples?

[John Mason]

Dave, the main-phase of sealevel rise was over by then: yes it continued to rise but the slope was low. Here's the shape of it:



You can see that the slope-break was ca. 7500 years BP.

WRT iron sulphides, I remember chatting to a fellow postgrad years ago (yes, it was that long ago) who was looking at their formation in present-day estuarine deposits. They do seem to form very easily if the conditions are reducing in nature. Might be why in Jurassic clay sequences the pyritised ammonites are 3D whilst those which are not are plain flat? That would suggest the pyritisation to be early in the compaction/diagenesis process, before too much loading from above from successive sediment layers.

Cheers - John

[ldavidcooke]

Hey John,

First, the melt rate could not have occurred at 17-10kya as over 200 quitillion tons of ice covered 2/3rds of the globe, sorry the graph is simply a misnomer by clear logic. As to land height in relation to the sea level it appears that a more pronnounced equitorial bulge was likely; but, unlikely to have exceeded 0.1% of the radius.

Secondly, in a reducing (acidification/hydrogenation) environment high in H2SO, the hydrogenation of the CaCO3 would have rendered the shell material to a near rubbery consistency. Hence, easily squashed and spread out like a pancake, without the need for sediment compaction, prior to entombment.

What is the basis of the evidence you have supplied, it makes no sense to me in light of simple scientific principles... Of course, for me to be 180 deg. off on a subject is nothing new...

[John Mason]

Dave,

WRT sea-level rise, see the following:

Fleming, Kevin, Paul Johnston, Dan Zwartz, Yusuke Yokoyama, Kurt Lambeck and John Chappell (1998). "Refining the eustatic sea-level curve since the Last Glacial Maximum using far- and intermediate-field sites". Earth and Planetary Science Letters 163 (1-4): 327-342. doi:10.1016/S0012-821X(98)00198-8

WRT pyritisation, I've seen enough evidence in the field! Often non-pyritised flattened or unflattened ammonites in claystone sequences retain the original aragonite of their shells. Pyrite pseudomorphing the inside of an ammonite shell, body, shell and all, would make it very resistant to squishing. I have 3D pyritised graptolites and orthocone nautiloids from the L Silurian of this part of the world, similarly preserved in great detail.

Cheers - John

[ldavidcooke]

Hey John,

If I recall correctly in 2007 we had a discussion that included Andre and several others here where we discussed the differences in sea levels with the over riding theme that heights were different then recently suggested. Matter of fact, I recall Dr. Schmidt and folks at RealClimate.org entertaining quite a long discussion on this issue, The papers referenced took a closer look at the Earths crust isoplasicity (isostatic compression) and eustatic displacement. The discussion even advanced to a discussion wrt the "farallon" plate and the issue of mid-continential plate faults... The end result being a discussion wrt Caribbean tectonic activity... Was there not a paper a few years ago discussing the Pacific "Ring of Fire" and why the lateral or latitudnal boundary occured nearer the poles rather then the Equatoial region?

As for the Amonites, my wife has several examples as well. Where the issue of "soft" versus "hard" shell really appears is in the surrounding matrix. Hers are clearly in a algae rich sediment and likely alive at the time of entombment. The 3D versions I have seen were in a silt/clay-sandstone/maural matrix with very little suggestion of a high H2SO environment. Most samples in this case were silt filled and well preserved, except were the surrounding sedimentry matrix displayed either displacement or fracturing.

So again I am sorry no papers to confound your suggested evidence; however, my personal field work does not appear to agree. Have you seen any work that may be more recent...?

[John Mason]

Hey David,

Quick response, as things to do, but two other lines of evidence WRT Cardigan Bay. Firstly, peat dredged from the seabed under 18.5 m of water gave a radiocarbon date of 8740+/- 100 YBP. Second, the main river-valleys hereabouts are filled with postglacial alluvial sediments to a depth of 40m below sea-level. This was a big problem that thwarted the 19th Century Plan A of sending the Cambrian Coast railway-line across the major estuaries: they couldn't cross the Dyfi because even tens of metres down it was all gloop! Hence the Glandyfi Junction station, several miles inland.

Cheers - John

[John Mason]

WRT the abstract you emailed me Dave, this is an area that was, like N Scotland, depressed under a massive weight of ice. Hence the deep Norwegian Fjords, the Scottish sea-lochs, around the fulcrum the silted-up glacial valleys of Mid-Wales and the drowned valleys of SW England, which was ice-free.

Cheers - John

[ldavidcooke]

John Mason, on 21 March 2012 - 18:13, said:

Hey David,

Quick response, as things to do, but two other lines of evidence WRT Cardigan Bay. Firstly, peat dredged from the seabed under 18.5 m of water gave a radiocarbon date of 8740+/- 100 YBP. Second, the main river-valleys hereabouts are filled with postglacial alluvial sediments to a depth of 40m below sea-level. This was a big problem that thwarted the 19th Century Plan A of sending the Cambrian Coast railway-line across the major estuaries: they couldn't cross the Dyfi because even tens of metres down it was all gloop! Hence the Glandyfi Junction station, several miles inland.

Cheers - John

Hey John,

Was well aware of this, an example can be seen near Bristol as well. On the East coast the "Night of the Great Rail Disaster", appeared to have been rooted in a similar problem. A gloppy channel to about 20 meters, a great sandstone base to 40 meters, had they dropped the core another 20 meters they would have found another 60 meters of glop to sandstone and eventually bedrock. Instead they decided to "float" piers of amalgam and concrete. A strong blow, a rushing flow, and 2000 tons of steel and 200 saints are buried under 30 meters of water.

Similar issues can be seen near most river mouths, the most famous examples, the Nile and the Amazon. The issue of sea level does remain, we really do not know if the Med. or Black Sea filled due to the △ in MSL or the subsistence of the land. For instance how much has the Med. basin risen due to the Africian Plate overtopping the European and how much has it fallen due to glacerial recession?

Pop 200 Quintillon tons on the ends of a balloon filled with magma and the middle will bulge significantly, no fulcrum required...