Little Heath Pit is a geological Site of Special Scientific Interest at Little Heath near Potten End in Hertfordshire. It is part of the

Ashridge Estate Ashridge is a country estate and stately home in Hertfordshire, England in the United Kingdom. It is situated in the Chiltern Hills, an Area of Outstanding Natural Beauty, about north of Berkhamsted and north west of London. The estate com ...

, owned by the

National Trust The National Trust, formally the National Trust for Places of Historic Interest or Natural Beauty, is a charity and membership organisation for heritage conservation in England, Wales and Northern Ireland. In Scotland, there is a separate and ...

, and the local planning authority is

Dacorum Borough Council The Borough of Dacorum is a local government district in Hertfordshire, England that includes the towns of Hemel Hempstead, Berkhamsted, Tring and Kings Langley. The district, which was formed in 1974, had a population of 137,799 in 2001. Its ...

.Information board on the site It is listed in the

Geological Conservation Review The Geological Conservation Review (GCR) is produced by the UK's Joint Nature Conservation Committee and is designed to identify those sites of national and international importance needed to show all the key scientific elements of the geological ...

. The lowest layer is gravel dating to the beginning of the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

2.6 million years ago. At this time the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea, epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the ...

covered much of south-east England and the site was in an inter-tidal area, but since then the Chiltern Hills have risen 170 metres. Above this gravel layer is sand, and then another layer of gravel laid down some 20,000 years ago. This was the height of the last ice age, when the site was cold

tundra In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mou ...

like western

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive region, geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a ...

today. According to

Natural England Natural England is a non-departmental public body in the United Kingdom sponsored by the Department for Environment, Food and Rural Affairs. It is responsible for ensuring that England's natural environment, including its land, flora and fauna, ...

the site is "controversial" as the new excavation shows gravel of possible marine origin rather than glacial

till image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is d ...

as previously believed. The size of the site is unclear. In April 2012 the Planning Inspectorate gave consent for the erection of fencing round the site to allow re-excavation of the site while protecting it against badger damage and protecting the public against accidentally falling into the deep pit. The size was given as 360 square metres (0.036 hectares). The excavation and erection of the fence were carried out shortly afterwards. However, the

(NE) citation gives the area as 0.3 hectares and the NE map shows a larger area of 1.2 hectares. There is access to the site from Bullbeggars Lane. The surrounding area is wooded and covered in deep pits called locally 'dells''. These are the remains of working to extract the gravel during

World War One World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

to make sandbags of use at the front. Information board placed at the site by Hertfordshire Geological Society.

References

{{coord, 51.7633, -0.5278 , type:landmark_region:GB-BNE, display=title Sites of Special Scientific Interest in Hertfordshire Dacorum Geological Conservation Review sites