Day Three

Tresco – a bright and breezy day with another bouncy boat trip followed by a long haul from our drop off point to the sampling locations. We first of all checked out a potential sample site at Bathing House Porth – but to no avail – we could see no peat – although there were some walls.

We then moved to the larger peat deposits that had been previously mapped and sampled by English Heritage in the 1990s. Here there are a series of wall running down the beach from the land into the sea and the peat deposits were recorded as lying close to these walls.

We marched along the beach and quickly located extensive peat deposits that were indeed near to the walls.

The deposits were visible as a large area of peat running along the shoreline, just as the finer lower sands became covered up by an upper band of stones.  We mapped the visible peat and also used our augur to sample down through the lower sands to see if the peat was lying below.  We covered an area that centered on the peat and moved out from the centre along and down the shore.   At the top of the shore the peat ran under the stones, we discovered this by digging along the surface of the peat up slope until the stones became too deep to excavate.   Wherever we found peat we mapped its location in 3D, keeping a record of what it was covered by or lay over, in this way we can create 3D maps that will show slices through the beach.

Once we located the deepest depth of peat we sampled, once again we used monolith tins.

We had a little trouble with water running into our pit, but this was solved by digging a series of gullies around the perimeter to divert the water away.  The upper one had preserved plant material and distinct banding visible in the organic part of the sequence.

We also took a core from a second, much shallower, peaty deposit lower down the beach.  We have been finding that, in some locations, the peat lies over clay (as can be seen in our monolith section), whilst in others it lies over the ramm (the reddish material visible in every section in Scilly – laid down at the end of the last glaciation).     The clay can be very deep and sometimes shows banding which suggests very still water, possibly when the island first became inundated with fresh water?

We were racing against the tide to finish the samples and ended up backfilling both pits just ahead of the sea.

We then had to carry back our rather heavy samples to Carn Quay to catch the boat.  We very nearly had to walk to Old Grimsby with all the stuff but luckily Bryher Boats managed to pluck us away.   We met our landlords on their way off the island, and they told us that our surveying equipment had made it onto the Scilly webcam – stood proudly alone on Bryher beach whilst we nipped off for a quick cup of tea.

I have been trying to find a way of posting this blog – but it is proving rather difficult.  I asked at the tourist office and it seems that the entire harbour is Wi-Fi enabled courtesy of the Duchy – so I could blog on my yacht (if I had one) or just perch on the harbour wall.  I did ask ‘what about when it rains?’ and the quick reply was to ‘wear waterproofs’.  Hmmm – I wonder can I get Harbour Wi-Fi from the Mermaid?

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