3000BC?

3000BC? 

The coast of south-western Norway showing bathymetry of Norwegian Channel and North Sea 

Rogaland coastline with sites discussed by Lisbeth Prøsch-Danielsen in her report.

Rogaland is a county of Norway which is centred around a complex water inlet from the Norwegian Channel called Bocknafjord. It is at the most southerly end of the west coast of Norway. This piece of coastline exceeds 150 kilometres in length, and is generally relatively low lying.

In this locality, there are over a dozen sites, which have been observed and excavated over many years. At these places evidence was found that sea levels have risen here and dumped beach type sand and gravel deposits onto inland areas.

All these beaches have arrived since the deglaciation of Norway, often at times, and locations, when animals, plants, and people of the Mesolithic and Neolithic Ages were present.

Lisbeth Prøsch-Danielsen in her report entitled “Sea-level studies along the coast of southwestern Norway with emphasis on three short-lived Holocene marine events” documents a lengthy period of study by herself and others into raised beaches along this Rogaland coast.

Her work describes that as a result of sea level changes in the Norwegian Channel two major events have caused deposition of beach material on this landscape, between 11,000 and 9,000 years ago, and between 7,500 and 4,500 years ago.

Also, at about a dozen coastal locations (Fig 68) evidence of a small additional period of sea level rise has been discerned, the third of the “three short-lived Holocene marine events” in the title of her report. This event commonly occurs in association with carbon dated finds of about 4800 years before present, and is sometimes named as the “4800yr BP event”

At the core of Lisbeth Prøsch-Danielsen’s account is her report on her own excavation at Stavanger airport Sola site, in Sola municipality. There she carried out large scale excavations, producing detailed stratigraphic records, and multiple carbon dates for sequences of events.

Fig 11 Beach deposits at Stavanger Airport Sola site

There, she found a ground surface from which a Black Alder tree had been growing, and in an event that caused a marine gravel to be deposited on the surface of the land, in around 3000BC (4320±70 yr BP (ß-171185)) the tree was ripped away, leaving only it’s roots.

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Fig 12 Section drawing showing buried land surface with tree roots cut off.

As the authors of the report had no previous knowledge that might suggest that a fragile undersea cliffs in the middle of the North Sea, they define this phenomenon as a consequence of local sea level rise.

However, in an alternative interpretation it is likely that a series of small tsunamis, derived from the collapse of those undersea cliffs, resulting in deposition and erosion processes which dumped marine gravel here repeatedly over an extended period of time.

Waterside cliffs, or submarine cliffs, that backed onto Dogger Bank, and were opposite the Rogaland coast, slowly collapsed as tides connected between the English Channel and the northern North Sea,  with the removal of the "Anglo-Dutch Neolithic Corridor "

Gradually after that, as the North Sea opened out, sediments on the east coast of Caithness and Orkney were stripped away, and the Orkney and Shetland archipelagoes were separated from Mainland Scotland.

 

Similar rresults 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," says Nielsen. 

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. 

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This is one of a loosely attached group of blogs called the "Orkney Riddle".

The key blog to the group is called the "Neolithic Immigrants to Britain" 

All views and opinions expressed are my own, but it remains a work-in-progress for which positive criticism and comment is welcomed.

Jeffery Nicholls 

South Ronaldsay 

Orkney 

Jiffynorm@yahoo.co.uk