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22-655: Bouldnor Cliff is a submerged prehistoric settlement site in the Solent . The site dates from the Mesolithic era and is in approximately 11 metres (6 fathoms) of water just offshore of the village of Bouldnor on the Isle of Wight in the United Kingdom. The preservation of organic materials from this era that do not normally survive on dry land has made Bouldnor important to the understanding of Mesolithic Britain, and

44-418: A large trench is dug and deliberately preserved (not filled in), often for transport purposes. This is typically done to install depressed motorways , open railway cuttings , or canals . However, these large, permanent trenches are significant barriers to other forms of travel, and often become de facto boundaries between neighborhoods or other spaces. Trenches have often been dug for military purposes. In

66-595: A later a new site was discovered nearby (BC 5). The dangerous diving conditions in the fast flowing waters of the Solent make archaeological investigation particularly difficult and archaeologists have used several new techniques to make analysis of the sea bed easier. This has included 'box sampling' – collecting large areas of sea bed in metal tins to raise them to the surface and more thoroughly excavate their contents on dry land. Archaeologists have discovered large quantities of burnt flints, mounds of timbers and pits dug into

88-474: A sheltered river basin, rich in woodland and fed by a river at Lymington and drained by the Western Yar at Freshwater . As sea levels rose, the Solent eventually flooded and the settlement area was swamped. The rising waters deposited silt and mud onto the original land surface, covering and preserving it. Fishermen had reported recovering stone tools from the seabed of the Solent since the 1960s, but it

110-534: Is exhibited in the Maritime Archaeology Trust's Sunken Secrets exhibition at Fort Victoria on the Isle of Wight. Research published in 2015 has identified wheat DNA at the site. As this wheat is of a type not native to Britain, it suggests the possibility of trade with Europe much earlier than had previously been supposed by archaeologists. This claim was questioned and it was suggested that

132-434: Is no longer known ("search trench" or "search slit"). Finally, trenches may be created as the first step of creating a foundation wall . Trench shoring is often used in trenchworks to protect workers and stabilise the steep walls. An alternative to digging trenches is to create a utility tunnel . Such a tunnel may be dug by boring or by using a trench for cut-and-cover construction. The advantages of utility tunnels are

154-638: The BBC Radio 4 's Making History programme described it "probably Europe's most important Mesolithic site" albeit concealed under water. The site was first discovered by divers from the Hampshire and Wight Trust for Maritime Archaeology (now the Maritime Archaeology Trust ) in 1999, when a lobster was observed discarding worked flint tools from its burrow on the seabed. Since then, several years of fieldwork have revealed that Bouldnor

176-604: The Crimean War , the American Civil War and World War I , until systems of extensive main trenches, backup trenches (in case the first lines were overrun) and communication trenches often stretched dozens of kilometres along a front without interruption, and some kilometres further back from the front line. The area of land between trenches in trench warfare is known as " No Man's Land " because it often offers no protection from enemy fire. After WW1 had concluded,

198-829: The Mariana Trench and the Aleutian Trench . The former geoform is relatively deep (approximately 10 kilometres (6.2 mi)), linear and narrow, and is formed by plate subduction when plates converge. In the civil engineering fields of construction and maintenance of infrastructure, trenches play a major role. They are used for installation of underground infrastructure or utilities (such as gas mains , water mains , communication lines and pipelines ) that would be obstructive or easily damaged if placed above ground. Trenches are needed later for access to these installations for service. They may be created to search for pipes and other infrastructure whose exact location

220-483: The "trench method" is used for searching and excavating ancient ruins or to dig into strata of sedimented material. In geotechnical engineering , trench investigations locate faults and investigate deep soil properties. In trench warfare , soldiers occupy trenches to protect them against weapons fire and artillery. Trenches are dug using manual tools such as shovel and pickaxe or heavy equipment such as backhoe , trencher , and excavator . For deep trenches,

242-491: The clay at BC 5 had been filled with burnt clay nodules, charcoal and burnt stones, which had been covered with a large piece of wood. Examining the pit walls revealed that the pit had probably been filled with hot stones on several occasions. Other trenches have revealed chipped wood flakes, flint knapping flakes and even wound fibres that appear to have been used as string. Many of the finds suggest evidence of small-scale industry as well as settlement. The work done at Bouldnor

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264-525: The ground. Wood from this era does not normally preserve well in land environments, so the quantity of wood found at Bouldnor makes the site of international importance. Under a large mound of worked timbers at BC 5, archaeologists discovered large areas of burnt clay, burnt flint and charcoal, which has been interpreted as the floor of a living space. Other timbers show signs of having been extensively worked on. Some split oak suggests that particularly large structures, or possibly boats, were being constructed at

286-630: The instability of steep earthen walls requires engineering and safety techniques such as shoring . Trenches are usually considered temporary structures that are backfilled with soil after construction or abandoned after use. Some trenches are stabilized using durable materials such as concrete to create open passages such as canal and sunken roadways. Some trenches are created as a result of erosion by running water or by glaciers (which may have long since disappeared). Others, such as rift valleys or oceanic trenches , are created by geological movement of tectonic plates . Some oceanic trenches include

308-542: The pre- firearm era, they were mainly a type of hindrance to an attacker of a fortified location, such as the moat around a castle (this is technically called a ditch ). An early example of this can be seen in the Battle of the Trench , a religious war , one of the early battles fought by Muhammad . With the advent of accurate firearms, trenches were used to shelter troops. Trench warfare and tactics evolved further in

330-627: The reduction of maintenance manholes, one-time relocation, and less excavation and repair, compared with separate cable ducts for each service. When they are well mapped, they also allow rapid access to all utilities without having to dig access trenches or resort to confused and often inaccurate utility maps. An important advantage to placing utilities underground is public safety. Underground power lines, whether in common or separate channels, prevent downed utility cables from blocking roads, thus speeding emergency access after natural disasters such as earthquakes , hurricanes, and tsunamis. In some cases,

352-631: The site. Another timber shows signs of having been fashioned as a type of conduit , which is not something that has ever been seen in Mesolithic archaeology before. Some of the worked timbers indicate technological skills that had previously only been associated with the Neolithic era, 2000 years later than Bouldnor. Burnt hazelnuts and oak charcoal have also been found at BC 5. Like the wood, these types of organic material do not normally survive well in dry, land based, environments. A pit dug into

374-403: The trench became a symbol of WW1 and its horrors. Trenches are used for searching and excavating ancient ruins or to dig into strata of sedimented material to get a sideways (layered) view of the deposits – with a hope of being able to place found objects or materials in a chronological order. The advantage of this method is that it destroys only a small part of the site (those areas where

396-506: The trenches, often arranged in a grid pattern, are located). However, this method also has the disadvantage of only revealing small slices of the whole volume, and modern archeological digs usually employ combination methods . Trenches that are deeper than about 1.5 m present safety risks arising from their steep walls and confined space. These risks are similar those from pits or any steep-walled excavations. The risks include falling, injury from cave-in (wall collapse), inability to escape

418-1004: The wheat DNA was too pristine and probably represents contamination. However, the original authors published a response to this contested point. Prehistoric settlement of the British Isles Prehistoric settlement of the British Isles refers to the earliest establishment and expansion of human settlements in locations in the British Isles . These include: Trench In geology , trenches result from erosion by rivers or by geological movement of tectonic plates . In civil engineering , trenches are often created to install underground utilities such as gas , water , power and communication lines. In construction , trenches are dug for foundations of buildings, retaining walls and dams, and for cut-and-cover construction of tunnels. In archaeology ,

440-400: Was a settlement site about 8,000 years ago, at a time when lower sea levels meant that the Solent was just a river valley. The work done so far has already revealed that the technology of Mesolithic settlers was probably 2,000 years ahead of what had previously been believed. Investigations suggest that during the Mesolithic era, between 8000 and 4000 BC, the western Solent was

462-470: Was not until 1987 that the submerged remains of an ancient forest were discovered at Bouldnor. Later radiocarbon dating of pollen revealed this to be approximately 8,000 years old. Subsequently, regular dives revealed a submerged cliff east of Yarmouth with large quantities of peat that dated to a similar period. The Hampshire and Wight Trust for Maritime Archaeology began mapping the cliff face and selected four main sites of interest (named BC 1–4). It

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484-425: Was while diving in 11 metres (6 fathoms) of water on BC 2 in 1999, that divers noticed a burrowing lobster discarding worked flints from its burrow. The lobster had burrowed through thick mud deposits that had formed since the Solent flooded, and into the original surface of the cliff when the Solent was dry. Since 1999, divers have excavated at Bouldnor every year. Further discoveries were made at BC 2 and BC 4, and

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