The relevant article is in Current Archaeology 298. It is currently on sale in Smiths over the Christmas period, and no doubt some other newsagents. It is the issue for January 2015 but is released for sale in December 2014. It will eventually be uploaded on to their website, www.archaeology.co.uk, but this won't be for a few months otherwise nobody would buy the journal. It concerns the erosion of cliffs in Northumberland where archaeology is literally being washed away by the North Sea. On page 14 there is a schematic diagram of the site with the various sediment layers. It is almost unique in that it provides an almost complete Holocene sequence of soils and sedimentary layers going back to the Ice Age.
Actually it sits on some interesting bedrock, the Carboniferous sandstones embedded with coal seams and mudstones. The Carboniferous (which occurred a very long time ago however you might want to date it) and everything between this hard rock layer and the Ice Age tills is missing – wiped clean. Presumably glaciation was responsible.
There are two distinct layers of glacial till – once consisting of boulders with clay (a common form of till known as boulder clay) which is overlaid by a thick layer of clay with gravels and pebbles – which appears to denote a secondary glaciation event (but no jumping to conclusions). At some point after this a soil layer formed at some point in early Holocene and built up quite a thick girth (going by page 14). In this were discovered Mesolithic remains of occupation (possibly a working area with a hut of some kind) that included 1500 pieces of flint and flakes from working flint, and lots of hazlenut shells (a common food resource of Mesolithic people). Later, Neolithic farmers had arrived as there are stone cists and burial pits that appear to go down to the Bronze Age. Some time after this a thick layer of wind blown sand was laid down (represented as a dune formation) and in time this dune consolidated itself and new soil developed (worms and bacteria) and occupation in this period has been dated from Middle Iron Age to the late Roman period. At that point there was 'another catastrophic deposition of sand' (their words) right across what was a large area of the landscape and effectively buried the Roman archaeology. In the medieval period, at some point, soils developed once again across the sand dunes, and humans returned. In the Little Ice Age, renowned for its storms and the battering of the coasts of the eastern seaboard, another layer of sand was laid down. Eventually it was covered in a thin layer of soil and grass – as in present day.
The main point being made in this post is that a thick layer of sand was laid down precisely at the point where Steve Mitchell dated a dramatic rise in sea levels around the coasts of Britain, in the immediate post Roman period. His view was that the land was depressed – but why this happened is unclear. There is one idea abroad that sea level comes in a series of curves and this may be related to post glacial bounce – going up and down. Whatever, the laying down of a thick layer of sand would suggest coastal storms rather than actual sea level rise – but how far away was the sea 1600 years ago? We have to assume erosion has been continuous so the sea shore may have been quite a way out – but this has not been confirmed. See some video clips of the archaeology produced by a team of 13 year old local school children and the kind of teacher we all dream about, http://hirstparkmiddle.org/index.php/rescued-from-the-sea
The Mesolithic finds came from a single scoop from the bucket of the excavating machinery taking a wedge of the cliff away from top to bottom. It is thought they may have been the floor of a working area, or the inside of a hut or dwelling. They are said to date from 8000BC and this seems to indicate that at that time the top of the North Sea basin was under water – with the southern basin still dry land and protected by the Dogger Bank, a possible Ice Age deposit (an esker or the head of a glacier). How far the sea shore was from the site in 8000BC is a matter of conjecture – but the author appears to think it was close. He also suggests that Mesolithic people at this time were moving up from the North Sea basin to escape rising sea level, an idea based on the assumption sea level rise was gradual rather than dramatic. The map on the next page shows Orkney still attached to the top of Scotland and the Shetlands as a large single landmass – but this of course is conjecture and again is based on the idea of gradual sea level rise. Orkney may have remained attached to Scotland all the way down to 6000BC.
In the Neolithic and Bronze Age layer a Beaker burial was discovered (dating around 2400BC) which has similarities with the continent – particularly the Rhineland. Hence, migration across the North Sea was still feasible. How close was the continent 4000 years ago? Other level remains date as late as 1500BC.
Further up the sediment scale was a stone building from the Late Bronze Age built on top of a layer of peat which covered a Neolithic hearth – evidence of rising sea level/water table. However, the covering of sand was laid down in the early Iron Age (which began in Britain around 800BC) which is not surprising as the climate at this time has been compared to the Little Ice Age.
In the Middle Iron Age a house was built and debris from the hearth was dated 350-200BC, which marks the Middle Iron Age and a return to a warmer climate regime. The upper ash layer in the hearth was dated AD170-325 which suggests it was occupied throughout the period to late Roman (or at least into the 3rd century AD). We then have the late Roman sand dunes, thrown up by stormy weather if not by a rise in sea level. It is possible, perhaps, that the three sand layers represent three rises in sea level followed by a recession – the so called curve.
The archaeologist also came across some strange pits that went deep into the strata. Eventually he discovered they were medieval coal workings, known as bell pits. They have been filled in with slag and mining waste.
Finally, the piece ends with a global warming doomsaying about the Environmental Agency predicting a one metre rise in sea level this century. I am assuming this is a ploy to get funding as the cliff face continues to erode – rescue archaeology if you like. See also www.nwt.org.uk/rescued-from-the-sea