The Storm Chasers are Back!
Actually the Rising Tides team are back up in Orkney, Sanday
to be precise, trying to chase environmental signatures of the past while also
trying to dodge a weather bomb! So what
is it we are actually doing and what is a weather bomb? As those of you who have read any of our
previous work will know we are particularly interested in understanding
palaeo-environments, landscapes and geography in relation to past
societies. Our work on the mainland,
that is the mainland of the Orkney Isles, has reconstructed drowned landscapes
through geophysical, coring and diving work.
On Sanday, we have come chasing the records of a drowned forest. Sounds familiar? Well yes, in some ways it is
similar to those sites on the west coast of Wales, and from a much older time
frame the sites at Happisburgh where we
found the oldest footprints outside Africa last year. Here in Sanday however we are trying to link
back to that critical period in the development of human behaviour, the change
from hunter-gatherer in the Mesolithic to the farmers of the Neolithic.
So why Sanday? Well, for one reason that a “drowned” forest
has been written about in the past. In 1867, in the History or Orkney the Rev
George Barry reported a “strong
tradition that the harbour of Otterswick in Sanday was once a forest, which was
destroyed by inundation. “and further, a sample of the trees was obtained by Traill-Dennison
in March 1890. We walked the beaches
here and ran some speculative geophysics last summer with encouraging results
that led us to a bay on the west coast of Sanday where with great luck on a
particularly low tide we spotted a small raft of peat. Coring and measurement of its elevation confirmed
that it was equivalent to the Otterswick Bay samples and so here we are, back
again on a series of very low spring tides to get further samples.
So what’s the problem?
It’s December, there is limited daylight here and we have the “storm of the
century” approaching (think The Perfect Storm)!
The task therefore is to get some samples and undertake some more
geophysics before it hits. The tactics –
geophysics (always geophysics) but most importantly some serious extreme
geoscience sampling – a JCB! (for those of you who are not familiar with this
great vehicle, and actually its not a JCB that we are using, then it’s a
backhoe).
The results – instant
sections, great samples and all done before today with its horizontal sleet and
snow. We have now dug four test pits
(typically in fading light at low tide, actually it was dark!) and found the
peat. Significantly the peat we have dug
appears to be full of freshwater molluscs at the base but towards the top there
are articulated marine bivalves as well as whelks and other marine
molluscs. This is what we are after – it
documents the onset of marine conditions and allows us to begin to understand
how marine waters flooded across these Mesolithic landscapes. Elsewhere we have been augering in probable
infilled bays where we discovered more than 2.5m of peats and sands alternating
throughout the core. This documents the
interaction between the land and the sea and excitingly these cores are very
close to a multi-period archaeological site that started in the Neolithic and
continued intermittently until the Viking period. So mission accomplished so far….watch this
space
