Underwater Archaeology is defined as:
deposits and ship wrecks beneath the surface of water in the seas, oceans, lakes and rivers."
Wetland archaeology work focuses on essentially terrestrial areas that are permenantly or periodically waterlogged; examples include peat bogs, salt marshes, river and lake margins and the inter-tidal zone around the shoreline. Such areas generally have excellent preservation characteristics for organic (Carbon-based) materials such as timbers and bone.
Archaeological Survey:
The methodological process by which information is collected about the location, distribution and organisation of past cultures across a diverse range of areas. The areas related to Marine Survey are split into two distinct areas of work:
A survey may be:
The Holistic Survey is the most detailed survey that can be completed. It takes into account the entire archaeological site and provides data reports on all aspects of the composition of the site.
The survey may also be classified as:
Depending on the types of research questions being asked of the environment in question. Surveys can be a practical way to decide whether or not to carry out an Excavation (As a way of recording the basic details of a possible site.) and may also be ends in themselves, as they produce important information about past marine activities in context.
A special type of field survey is the Rescue Survey, used when an area of possible archaeological importance is under threat. This is usually connected to construction work, and is undertaken to decide whether an excavation is necessary or not before work can commence on the site.
ADA(UK) uses a variety of tools in survey work, including:
Research and Planning:
A survey is usually the result of a long period of research and planning. The process will normally start with the notion that an area is worth further investigation, or that a site requires excavation (or that it should at least be recorded in some way). There are several reasons that an area may be considered to be worth surveying. In no particular order, these are:
Artefacts Found:
Locals have picked up artefacts, sometimes found in the local museum but more often in private homes or old buildings such as churches, and it is unclear where they are coming from. Fashioned artefacts are the basis of what is called 'Material Culture'.
Literary Sources:
Old literary sources, in some cases ancient Roman or Greek texts, have provided archaeologists with clues about settlement locations that have not been archaeologically documented. Sometimes the texts may be quite recent e.g. a book on local history that mentions an interesting area.
Oral Sources:
In many locations, local stories contain some hint of a greater past, and there is often some truth to them. It is not uncommon for someone to recall stories told to them by relatives of past generations, that make mention of buildings or areas that they have never actually seen themselves.
Local Knowledge:
In many cases, locals actually know where to find something that is of interest to archaeologists. They may not have reported it, either because it's simply a part of their world, or because they fear intrusion on their land.
Previous Surveys:
In some places, a survey may have been carried out in the past, and recorded in an obscure academic journal. It may have been disregarded at the time, but more recent technologies and finds from other sites might cast a different light on it.
Previous Excavations:
Excavations carried out before the middle of the 20th century are notoriously poorly documented. They were also often carried out in a way that left much of the evidence that the modern-day archaeologist is looking for behind, preferring to carry away only fine pottery, jewellery and statues.
Lack of Knowledge:
In many areas of the world, little is known about the nature and organisation of past human activity at regional level. Even when one or more 'sites' may be known in a particular area, often little is known about the wider distribution of contemporary settlements, and how settlement patterns may have changed over time.
The term "features" in archaeology, and especially excavation, has several different but allied meanings. A feature is a collection of one or more contexts representing some human non-portable activity that generally has a vertical characteristic to it in relation to site stratigraphy. General horizontal elements in the stratigraphic sequence, such as layers, dumps, or surfaces are not referred to as features.
Features tend to have an intrusive characteristic or associated cuts. This is not definitive, as surfaces can be referred to as features of a building and free-standing structures with no construction cut can still be features. Middens (dump deposits) are also referred to as features due to their discrete boundaries. This is seen in comparison to levelling dumps, which stretch out over a substantial portion of a site. The concept of a feature is, to a certain degree, fuzzy, as it will change depending on the scale of excavation.