SCIENTIFIC BACKGROUND: If you were standing at these co-ordinates 6500 years ago you would be under water as virtually all of the area now known as the Somerset Levels was then covered by the sea and was part of the Severn Estuary. Around 6,000 years ago the sea began to retreat and reed-beds colonized the drying marshes, later to be replaced by sedges and finally fen woodland.
As plants grow they remove carbon dioxide from the air and replace it with oxygen. Normally when they die the reverse happens as aerobic (i.e. oxygen-requiring) decomposing bacteria gain their energy and raw materials for their growth by breaking down the green plant biomass that has been built up through photosynthesis. However, in these waterlogged marshes and reed-beds there is not enough dissolved oxygen in the boggy soil for these sorts of bacteria to thrive and so the plant material does not decay but builds up as peat. If buried deep underground and subjected to great pressure and heat the dead plant remains would become coal but this has not happened in Somerset. It is incredible to realize that one fifth of the Earth’s atmosphere that is the oxygen we breathe is only there because of the carbon locked away in the ground as fossil fuels (peat, coal and oil) or as calcium carbonate in rocks such as limestone, chalk and marble. The latter are made from the fossilized invertebrates that gained their carbon by eating plants and algae. If we humans were ever to do the impossible and burn or oxidize all these stores of carbon, not only would there be a 'runaway greenhouse effect' due to raised carbon dioxide levels in the atmosphere but the amount of oxygen would fall to levels below that necessary to sustain animal (including human) life.
From about 3000 BC rainfall increased in this region and the wetter conditions discouraged the growth of trees and nutrient levels deteriorated. Heather and cotton grass started to grow and the acid soil conditions encouraged raised bog growth until around AD 300.
The Romans are thought to have been the first to extract peat to burn for fuel. It was cut by hand for hundreds of years between the months of April and September when the ground was at its driest. The men would cut and the women and children stack the turves to dry. In 1950’s other types of fuel became more popular and large-scale mechanized removal of peat for horticultural purposed began in the 1960’s. Thanks to the work of conservationists this destruction of the landscape ceased within 30 years.
LOCAL HISTORY OF THIS SITE: In Neolithic (polished stone age) times people began to settle on the higher drying ground in what is now the Brue Valley. They constructed wooden trackways to cross the wetlands. The Sweet Track (named after its discoverer Ray Sweet) is the most famous of these. It was built in 3806 BC to cross the 2km of reed swamp between Meare Island and the Polden Hills and is the oldest man-made routeway in Britain. Radiocarbon dating shows that it was repaired for at least 6 years but like most of the other tracks (which connected the ‘islands’ of Burtle, Westhay and Meare) it probably had a short lifespan of less than 12 years. Many artefacts including stone axes, flint arrowheads, a bow, pots containing hazelnuts and a polished jadeite axe from the Alps have been found beside these trackways. The county’s ancient name, Somerseata, means 'Land of the Summer People' and indicates that much of this wetland landscape was only accessible in summer.
Nearby at the Avalon Marshes Centre and the Shapwick Heath nature reserve you can see reconstructions of some of these trackways along with examples of the much later roundhouses discovered at what is known as Glastonbury Lake Village. These show the sort of housing people lived in during the Iron Age around 2,300 years ago. At its greatest extent the village had 15 roundhouses and was home to roughly 170 people at any one time. The roundhouse at the Centre is no longer safe for public access, but also at the site are reconstructions of part of a Roman villa and an Anglo-Saxon long hall, which should be open to the public in 2017.
To log this Earthcache post a photo of yourself with your GPS in hand in front of one of the mounds of peat which abound near the Visitor Centre and use the nearby noticeboards outside Eco-Friendly Bites to tell me via e mail which Arthur discovered the Glastonbury Lake Village in 1892.