Part of the main submerged forest exposure, with a bounding "trench" filled with water. The peat is very thin, grading down into blue clay which in places contains sub-angular stones.
Thin surface peat layer (c 10 - 15 cm) with bluish clay (partly gleyed) beneath. There are abundant dark-coloured organic fragments in the clay -- because of inclement conditions I could not ascertain whether these were detrital fragments of remnants of old root systems.
A thin peaty layer grading down into sticky stoneless grey clay.
Here the peaty (dark coloured) layer is c 20 cm thick, and it grades down through a "streaky" band to stoneless grey clay, passing beneath the water level. There is no sign of an erosional contact, and it appears that depositional conditions have been subject to gradual change.
In a few places sub-angular blocks of local sandstone are contained within the blue clay layer -- and some erratic pebbles are also incorporated in the clay -- but I would not refer to this as a till layer without further evidence.
One of Gary's 2014 photos, showing a thin cap of peaty material passing down to relatively clean grey-blue clay and then to blue-grey clay-rich till full of erratic pebbles and stones -- which
appears to be in situ.
According to Fitch and Gaffney (2011) there was "........ a rapid spread of open, mixed deciduous forest woodland, with hazel (Corylus avellana) and elm (ulmus) establishing an open canopy forest. The canopy closed within 500 years with the establishment of oak (Quercus), Lime (Tilia cordata), alder (Alnus glutinosa) and ash species (Fraxinus excelsior) (Roberts 1998). This strongly seasonal, high productivity woodland would have provided hundreds of edible plant species for human groups - available at a relatively low energy cost. However, the dense closed nature of the woodland would at times have been an obstacle to communities, making hunting and passage difficult. However, the presence of fluvial channels and lakes within the landscape would provide open areas which would have facilitated population movement.......... The regular longitudinal river profiles associated with the Pleistocene- Holocene transition suggest lower energy river systems than the previous period, and these may have been more suitable for travel using the logboats of the period. The rivers still produced high yields of sediment that in-filled deep Pleistocene channels and continued to contribute to the ponding up of lakes within the valley."
There was initially not much vegetation. There must have been extensive destruction on the rock faces of the old cliff line, under the influence of frost processes and gravity.
Later on, tundra vegetation became established, and herds of "Ice Age" animals including woolly mammoth, woolly rhinoceros, red deer, wolf, wild boar, giant ox etc roamed across the landscape. Further substantial river plains ran down from the uplands of South Wales, including the Tywi, Taf and Tawe to the west of the Glamorgan lowlands. There are traces of Palaeolithic occupation on Caldey Island and in the caves at Coygan and Paviland. As the sea-level rose gradually, many of the "Ice Age" animals became extinct as the climate and vegetation changed and the coastline approached its present position.
After 9,000 years BP there must have been an extensive forest, changing in character as the climate oscillated -- this forest covered both the terrain inland of the present cliff-line and the coastal plain which is now submerged beneath the sea. There were tree-covered hillocks and ridges between the main drainage routes. Conditions must have been favourable for the growth of peat within and beyond the tree-covered areas. The fauna changed gradually -- the woolly mammoth and the woolly rhinoceros became extinct, but species like wolf, fox, wild boar, red deer, and giant ox adapted to changing circumstances and survived. Human hunters now obtained some of their food from the forest, and AL Leach recorded many examples of microliths and other artifacts in the forest indicative of a population of Mesolithic nomads.
This is the first serious study of the submerged forest -- published at about the same time as the Geological Survey Memoirs and the studies around the South Pembrokeshire coast by AL Leach.