The Peninsula Emerges - Gower - page 41

water which had been locked up in the ice sheets was slowly released and covered these coastal wood-
lands.OffshorefromRhossili aredrownedrivervalleys, thechannels ofwhich,althoughpartially infilled
with sediment, are generally 5 metres deeper than the adjacent seabed. The general trend therefore has
been for low-lying coastal margins to become inundated, as shown by the submerged peat beds in areas
along the coast. In some cases tree remains are also found, the so-called 'submerged forests'. Describing
Oystermouth in Swansea Bay at the end of the seventeenth century, Isaac Hamon wrote 'The sea hath en-
croached upon a great part of the low grounds of this parish, as appears by the roots of trees, and whole
trees that lyes in the sands and other tokens.' Other remains of the forest have also been uncovered in the
past in Port-Eynon and Broughton bays.
Comparatively little research has been carried out on the remains of this past habitat, much of the in-
terest being centred on the geology and animal fossils present. As Neville George (1930) remarked, 'it
cannotbetoostronglyemphasisedthatmuchoftheinterestoftheForestrestsinitsbeingaforest,andthat
a considerable portion of the material consists of an abundant and varied flora; an investigation by some
competent botanist of this rich and practically untouched assemblage could not fail to prove exceedingly
illuminating.' Species recorded include silver birch Betula pendula , hazel Corylus avellana , alder Alnus
glutinosa , elder Sambucus nigra , deergrass Trichophorum cespitosum , rushes Juncus spp., irises Iris spp.
and spurges Euphorbia spp. Leaves of pedunculate oak Quercus robur have also been found. This group
ofplantsischaracteristicoflow-lyingwethabitatswithdrylandnearbyandrepresentsasimilarhabitatto
that existing today in parts of Oxwich marsh. Insect remains include the wing-cases of beetles such as the
dung beetle Geotrupes vernalis , which appears to have been fairly common and was probably associated
withthepresenceoflargeranimals,includingroedeer Capreolus caprea ,reddeer Cervus elaphus andox
Bos taurus.
THE CREATION AND DISTRIBUTION OF SAND
The grinding action of ice flow and glaciers, when the majority of northwest Europe lay under thick ice
sheets, formed sands and gravels. After the last glaciation, some 6,000 to 8,000 years ago, a period of
global warming produced large volumes of meltwater, which transported these materials into the river
systems and near coastal waters. When the sea level rose it reworked these sands and gravels and pushed
them shorewards, until they lay at or near the heads of bays. These sediments are not being significantly
renewed by natural processes and are therefore a finite resource. Although the Bristol Channel once con-
tained vast reserves of this 'glacial outwash' research has shown that there is a long-term and generally
westward transport of sand out of the area, leaving behind a largely rocky seabed with a sparse covering
of sediment.
The high tidal range of the Bristol Channel results in wide expanses of sand being exposed at low
water, and when conditions were suitable some of this was blown inland, leading to the development of
coastal dune systems. Near the northwestern end of Whiteford Point peat, containing leaves, roots and
other plant material, is exposed just below the high-tide level and represents a former land surface. It has
not been dated, but Bronze Age remains have been recorded on top of the clay and beneath the dunes
that fringe Broughton Bay, with Roman remains on the overlying sand. This indicates that sand began to
moveinlandinsignificant quantities intheIronAge,aroundthefirstmillennium BC. Thisprocesscontin-
ued for centuries, although there was a considerable increase in storminess in northwest Europe from AD
1200, which continued after a slight improvement in the fifteenth and early sixteenth centuries into the
seventeenth and eighteenth centuries. The seventeenth and eighteenth centuries have been described as
the 'Little Ice Age' because of the increase in the size of the European mountain glaciers that took place
during this time. The environmental evidence is backed up by documents that record devastating sand