Archaeology in the North Sea
Archaeology in the North Sea
The Orkney Vole is thought to have been imported, by uncertain means, to the archipelago from mainland Europe without setting foot on mainland Britain.
How this happened is a bit of a mystery.
Summary
A complex series of shallow inland seas "The Marr Bank Lagoon" were carved out along the east coast of Britain from about 70,000BP. They were not directly connected to the Norwegian Channel or the Norwegian Coast, but were separated from it by a ridge of land , north from Dogger Bank to the Atlantic Ocean.
In this period from 70,000BP to 40,000BP the mountains of northern England and Scotland were capped with thick snow, and the Shetland icecap was in a continual condition of collapse, blocking the Marr Bank Lagoon at the north.
The Marr Bank Lagoon was surrounded by a shoreline which was backed onto the icesheet on all sides. Evidence suggests that the Lagoon did not freeze over.
At around 40,000BP animals and people were inhabiting southern England, southern Ireland and the shores of the Marr Bank Lagoon.
Between 40,000BP and 21,000BP snow precipitation lay on dry land across most of Britain and the North Sea, but not on the shores of the Marr Bank Lagoon at the east coast of Britain. These would have supported wildlife, including the European Vole.
The survival of animals on the shores of the Marr Bank Lagoon would not necessarily have been compromised, but there was enough snow cover on that coast of mainland Britain to prevent this animal population from transgressing onto land that would become Britain.
The deglaciation, when it arrived lasted over a period of 10,000 years, from around 21,000BP to 11,000BP.
Mostly the deglaciation weeped away the melting ice, but in some short periods of warm summers the melting was so fast that the edges of ice-sheets collapsed causing impact valleys to be excavated on the land that had supported them.
This was also a time when huge volumes of meltwater were released from the glaciers to flow over lowland Britain, dumping moranic debris across the landscape, and causing sea levels to rise locally around the coasts of Britain.
Somewhere in the timings of these hugely catastrophic events the European Vole maintained a foothold on land adjacent to Orkney, and as sea-levels rose they and other surviving species retreated to the nearest available land.
The European Vole remains on Orkney to this day, as the Orkney Vole.
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Some of the academic rationale for this event is reviewed in the blog:- The Orkney Vole. (Authors, Keith Dobney and Natalia Martinkova)
Here, in an alternative research discussion, I outline evidence that supports the notion that land in the area now occupied by the North Sea has, in some places, been accessible to animals and humans throughout the last 70,000 years.
This notion is in conflict with existing strongly held hypotheses about ice age Britain, but it is based on available evidence gathered over recent years, much of which seems to have been overlooked by those in academic authority.
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Initially, in order to establish the possibility of land being present in the middle of the North Sea in prehistoric times the undersea features there need to be recognised. These are in simple terms, Dogger Bank, the Witch Ground and the Norwegian Channel.
Fig. 1, The British Isles and North Sea (Emodnet)
The Norwegian Channel is a deep water trench that follows the Norwegian Coast from the Skaggerak, an even deeper section of the same trench, between Norway and Denmark, out to the North Atlantic Ocean.
Dogger Bank is an area of shallow water in the southern North Sea known to have been walkable land in prehistoric times, Doggerland.
The Witch Ground is one of a group of deep water features in the North Sea. It is off the North east coast of Aberdeenshire.
At the north of the North Sea the seabed is over 100 metres deep, but the Witch Ground is even deeper.
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A surge of meltwater flowing along the Norwegian Channel suggests that land was present on the west side of the Channel at 12,000BP.
The sea level charts for points along the Norwegian Coast, are published in "Post Glacial Relative Sea Level Change in Norway" by Roger C. Creel.
Fig. 2, Sea level charts for the Norwegian Coast (Creel)
There is, on the charts, a consistent pulse of 10 metres higher water level onto the Norwegian coast at 12,000BP when the ice sheets on Sweden were melting and draining into the Skaggerak.
The sea level in the Norwegian Channel, inferred from "Global sea-level rise in the early Holocene revealed from North Sea peats" by Marc P. Hijma, et al, was 60 metres below present at 12,000BP, but the peak of the meltwater surge out of the Skaggerak was then 10 metres above 60, therefore 50 metres below our sea level.
This surge of 50 metres below sea level was supported at the Skaggerak between the coasts of Norway and Denmark, and not diminished in any way until it had followed the Norwegian Coast and reached the Atlantic.
This means that there was land along the west bank of the Norwegian Channel at better than 50 metres below current sea level, where the seabed is now over 100 below.
Supporting that recognition, deposits in the floor of the Norwegian Channel indicate tthat huge amounts of material have been dumped there at the same time period, suggesting that slurry-rich waters had been running along the channel at that time.
Source:- Late Weichselian and Holocene sediment fluxes of the northern North Sea Margin by H. Haflidason, E.L. King, and H.P. Sejrup
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| Location Troll core 8903 in the Norwegian Channel. |
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| Graph demonstrates that massive amounts of sediments were dumped in the Norwegian Channel floor during the period when the the pulse of raised water levels was flowing the channel, around 12,000BP. |
This suggests that there was land at the west coast of the Norwegian Channel at shallower that 50 metres below sea-level that people and animal may have used to walk from Doggerland north to the Atlantic coast of the North Sea.
Fig. 3, The flint artefact (Long)
To confirm this possibility, There is evidence of human activity in the middle of the North Sea. In a report entitled "A flint artifact from the northern North Sea" . Caroline Wickham-Jones discusses a struck flint artefact found in a borehole in the North Sea, half way between Shetland and the North Sea, ("A flint artifact from the northern North Sea" By Long, D., Wickham-Jones, C.R. and Ruckley, N.A. 1986). This may indicate that people were foraging in this area in prehistory. It is certainly difficult to conceive how a knapped flint got to that place otherwise.
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The high ground that bordered the west coast of the Norwegian Channel was not attached to the east coast of Britain. It was separated from that coast by a series of shallow water inland seas (Marr Bank Lagoon). These developed, and were maintained between (roughly) 60,000BP and 10,000BP.
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| Fig. 4 |
They were in the locations of geological features known as the Swatchway Formation, the Marr Bank Formation, the Wee Bankie Formation (not shown) and the Bolders Bank Formations. These interconnected features were enclosed at the north by the Capeshore Formation, which was a meltwater runoff deposit accumulated throughout MIS 5, 4, and 3, as the Shetland ice cap collapsed.
As continued melting water drained into the Marr Bank Lagoon from the north, and from all sides, it overflowed out to the Norwegian Channel around the south coast of Dogger Bank.
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| Fig, 5. Location map of Capeshore Formation in sea floor of the northern North Sea |
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| Fig. 6. Section east to west from Shetland to the Norwegian Channel in the sea floor of the North Sea |
The Capeshore Formation material is described as "Soft to firm, highly to moderately silty clay with sporadic shell fragments and pebbles." (BGS)
"The foraminiferal assemblage is dominated by E. clavatum, Cassidulina reniforme Norvang and Protelphidium orbiculare . " (The geology of the northern North Sea. United Kingdom Offshore Regional Report", By H Johnson,)
In "Distribution of recent Benthic foraminifera in Kongsfjorden and Krossfjorden; North-West Svalbard, High Arctic"by Debolina Chatterjee et al, the presence of E, clavatum in Svalbard, the high arctic, is discussed.
"The Cassidulina reniforme–Elphidium clavatum, Textularia spp. assemblage dominates the foraminifera fauna near the glacier proximal that indicates increased sedimentation and meltwater runoff." (Chatterjee)
This marker species confirms that meltwater was running away from Shetland probably through MIS 5, 4, and 3.
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| Fig. 7. Plan and section of sea floor deposits , including the Swatchway Formation, demonstrating its' proximity to Orkney. |
In "The geology of the central North Sea. United Kingdom offshore regional report", by R W Gatliff, the Swatchway Formation is described as follows,
"......the sparse, benthonic foraminiferal assemblage is dominated by the cold-water species E excavatum var. clavatum, which suggests deposition in boreal to arctic seas (Stoker et al., 1985). Perhaps more significantly, the foraminifera are accompanied by moderately abundant populations of dinoflagellate cysts; a limited spectrum is co-dominated by O. centrocarpum and Bitectatodinium tepikiense Wilson, indicating northern cool-temperate conditions without significant sea-ice cover (Harland, 1988a). The formation can be broadly assigned a late Weichselian age (Stoker et al., 1985)."
The Witch Ground, which is the deep feature cutting into the Swatchway Formation was not present at the same period as that in which the Swatchway Formation was part of an inland sea. This is dated to 18,000BP, and is an impact valley group caused by the collapse of the ice sheet, which was probably retreating north-east towards Norway.
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| Fig. 8, Plan of sea floor deposits outcropping on the east coast of Scotland and England. Showing locations of section drawings below, and location of Marr Bank Formation. |
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| Fig. 9, Sections of Marr Bank Formation |
Of the Marr Bank Formation.......
"A poor ostracod fauna and a moderately abundant population of foraminifera (Thomson, 1978) indicate that the shallow waters in which the formation was deposited were high-boreal to arctic in temperature, and inner shelf to estuarine in character."
The Marr Bank Formation merges with the Wee Bankie Formation, which then merges with the Bolders Bank Formation.
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| Fig. 10, Location map of Bolders Bank Formation as it curves around the southern end of Dogger Bank. |
The Bolders Bank Formation also merges with the Dogger Bank.
"The Bolders Bank Formation characteristically consists of reddish to greyish brown, stiff diamictons that are generally massive but in places possess distinct, commonly arenaceous layering, and deformational structures. The majority of its pebbles, of which chalk is the most conspicuous component, are derived from the sedimentary rocks of eastern England. The pebble content tends to diminish eastwards. In general, the formation is less than 5 m thick, and commonly less than 1 m is preserved in deep-water areas west of the Dogger Bank, although to the east of Lincolnshire it may be 15 to 20 m thick (BGS Spurn Quaternary Geology sheet). " ("The geology of the southern North Sea. United Kingdom offshore regional report" By T D J Cameron et al)
The full sequence of deposits offshore from England and Scotland consist of just the four formations that are dated to the period after 60,000BP. They are the Swatchway Formation, the Marr Bank Formation, the Wee Bankie Formation, and the Bolders Bank Formation. This group are blocked at the north by the meltwater runoff derived from the collapsing Shetland icecap, and retained at the south by rising seabed around the south coast of Dogger Bank.
There is little evidence of ice cover on the Swatchway and Marr Bank Formations, which were laid in conditions that were markedly warmer than might be expected in the middle of an ice age:-
"Fluvial sand and gravel exposed in quarries near Tattershall contain evidence of a short but marked mid-Devensian climatic amelioration (Girling, 1974). An organic silt bed within involuted gravel overlying the Ipswichian peat has yielded insects indicative of a high-latitude continental tundra environment, but a slightly higher bed contains a thermophilous insect fauna—some taxa of which are now confined to southern Europe—implying summer temperatures at least as warm as those of southern England today. Radiocarbon dates from these deposits and correlatives elsewhere in England show that this warm interval, the initial phase of the Upton Warren Interstadial Complex, occurred around 43 000 years ago. It was too brief for the climatic improvement to be reflected in the flora. The overlying sand and gravel in the Tattershall area are appreciably cryoturbated and contain numerous remains of mammoth (Mammuthus primigenius), woolly rhinoceros (Coelodonta antiquatis), bison, reindeer and other tundra-favouring mammals.” (Eastern England from the Tees to The Wash. British regional geology, by Sir Peter Kent)
The Orkney Vole was present in the Orkney archipelago in the human Neolithic period, but not present in the remainder of Britain at any time. An explanation for the vole being in Orkney but not Britain may be as follows:- The shores of these inland seas were warm enough that , even when the last glacial maximum began to develop, they were favourable to the survival of the small rodent, and other prehistoric animals.
In addition to this though, during the cold period of the last glacial maximum, all of eastern Britain from Dover to Orkney was ice covered. The Orkney Vole would have been restricted in its range to the shores of the inland seas, and unable to make landfall on mainland Britain due to the snow cover.
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The ridge of land that separated the Marr Bank Lagoon from the Norwegian Channel has been removed as a result of rising sea levels.
The date at which this happened may be found in a report of excavations of raised beaches on the Norwegian Coast that was carried out by Lisbeth Prøsch-Danielsen (Sea-level studies along the coast of south-western Norway, by Lisbeth Prøsch-Danielsen) At the "Stavanger Airport Sola Site"
Fig, 11. The Rogaland coast of Norway (Prøsch-Danielsen)
Danielsen demonstrated that there were a couple of transgressive rises in sea level after the end of the last ice age. She also found an anomalous event which she could give no explanation for, in which an alder tree was ripped from its roots at a site in Rogaland, near Stavanger. “The layer consisted of organic and sand (mica schist) lenses sandwiched on top of each other, dipping towards the east. Between layer 3 and layer 4 there is an erosional angular unconformity. Also roots of black alder (Alnus glutinosa) (identified by Aud Simonsen) penetrating into the upper part of the marine gyttja have been cut of discordantly. A piece of root has been dated to 4320±70 yr BP (ß-171185).”. The date was calibrated to just after 3000BC, and I interpret that the roots may have been stripped of their tree by a very local tsunami wave, rolling across the Norwegian Channel.
Similar results to those at Stavanger airport Sola site, were found at other archaeological sites in Rogaland, where tsunami-type deposits are found.
Talking to Bård Amundsen, a journalist for sciencenorway.no , Svein Vatsvåg Nielsen and his German colleague Martin Hinz say:- "We now consider it certain that the sea level rise was brief. It also seems likely that a tsunami struck the Stone Age people in Rogaland – and probably also Vest-Agder – sometime between 3445 and 3396 BCE,"
Nielsen and Hinz suspect that it may have been the Garth tsunami, named after the Garth Loch lake in Shetland.
Jåsund 2 is the name archaeologists have given to one of the most well-known Stone Age settlements in Rogaland. It is located on the Tananger Peninsula in Sola municipality, just outside Stavanger. Evidence suggests Jåsund 2 was flooded by a wave possibly as high as 10 metres.
They have also discovered evidence of the Garth tsunami, which may have hit southwestern Norway 5,400 years ago, on Shetland. The sediments left behind by this tsunami are similar to those from the Storegga tsunami. In this case, the wave run-up on land is over 10 metres.
Håkon Glørstad, who first proposed the tsunami theory in the 1990s, is pleased that Nielsen and Hinz have now confirmed it in a new scientific article. "At the time, much of what we uncovered in archaeological digs in Rogaland didn’t make sense," Glørstad tells sciencenorway.no. "But I realised something dramatic must have happened, something involving water, that was unique to Rogaland. It had to be a fairly local phenomenon," he says.
Fig. 12. The bathymetry of the Norwegian Channel
The position of this coastal region of Norway which makes it likely to have been affected by such a wave is exactly opposite the narrowest neck of land between the Witch Ground and the Norwegian Channel.
Fig. 14, A section along the length of the Norwegian Channel
A dump of sedimentary material is to be found in the floor of the Norwegian Channel at this location, and is likely to have been caught up with the collapse of the side wall of the channel. It is recorded in a section along the channel surveyed by Hans Petter Sejrup in "Quaternary of the Norwegian Channel: glaciation History and palaeoceanography”
When the tidal waters of the Atlantic reached into the non-tidal flow of the Norwegian Channel they rapidly stripped the northern North Sea of over 50 metre depth of deposits.
At the same time similar quantities of structural land-based sediments are likely to have been removed by marine erosion from the locations that link Scotland to Orkney and Shetland.
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The last ice age is not well understood at present, but the research that has been necessary to plot a path by which the European Vole transformed itself into the Orkney Vole required a series of shifts in my perception of Quaternary landscapes.
One of the significant understandings that i needed to develop, in order to make sense of our landscape, and the geology that we live amongst was a novel idea about the formation of valleys . This i have defined in "Parallel Valley Arrays" drawing on personal experience, travelling, and working, in the hills and valleys of Britain.
In addition, the better understanding of Ice Age Britain is attempted in "Ice Age Beginnings"
"Archaeology in the North Sea"
I was not just looking to understand what happened to the Orkney Vole. There is also the problem that people are supposed to have had boats in prehistory, at a time when there is little evidence of their existence. To plot the route by which people would have walked between Holland and Norfolk, I wrote "Walkable Land in the North Sea" which charts the existence of a land bridge allowing flora, fauna, and people, to commute between Europe and Britain.
The existence of land between Holland and Norfolk makes it easier to explain that a similar corridor of land would have linked Orkney to Scotland. This also explains how huge monuments could have been constructed by Neolithic people in a sparsely populated Orcadian environment.
Using archaeological evidence "Neolithic Migration to Orkney" tracks the occupation of Orkney from Neolithic to Bronze Age. It describes how the more sophisticated structures there, including Skara Brae, and the Ness of Brodgar, were the creation of small groups of people who became stranded on the islands when the link that joined them to Scotland was washed away by rising sea levels.
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All views and opinions expressed are my own. Many assertions stated have not been thoroughly justified here, simply because space prohibits it in this format. The evidence exists elsewhere to demonstrate that these assertions are, at their core, valid.
Jeffery Nicholls
South Ronaldsay
Orkney
Jiffynorm@yahoo.co.uk
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