archaeology Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, biofacts or ecofacts, sites, and cultural landsc ...
, excavation is the exposure, processing and recording of archaeological remains. An excavation site or "dig" is the area being studied. These locations range from one to several areas at a time during a project and can be conducted over a few weeks to several years. Excavation involves the recovery of several types of data from a site. This data includes artifacts (portable objects made or modified by humans),
features Feature may refer to: Computing * Feature (CAD), could be a hole, pocket, or notch * Feature (computer vision), could be an edge, corner or blob * Feature (software design) is an intentional distinguishing characteristic of a software ite ...
(non-portable modifications to the site itself such as post molds, burials, and hearths), ecofacts (evidence of human activity through organic remains such as animal bones, pollen, or charcoal), and archaeological context (relationships among the other types of data).Kelly&Thomas (2011). ''Archaeology: down to earth'' (4th ed.). Belmont, Calif.: Wadsworth, Cengage Learning. Before excavating, the presence or absence of archaeological remains can often be suggested by, non-intrusive
remote sensing Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring information about Ear ...
, such as ground-penetrating radar. Basic information about the development of the site may be drawn from this work, but to understand finer details of a site, excavation via augering can be used. During excavation, archaeologists often use stratigraphic excavation to remove phases of the site one layer at a time. This keeps the timeline of the material remains consistent with one another. This is done usually though mechanical means where artifacts can be spot dated and processed through methods such as sieving or flotation. Afterwards, digital methods are then used record the excavation process and its results. Ideally, data from the excavation should suffice to reconstruct the site completely in three-dimensional space.


The first instance of archaeological excavation took place in the sixth century BC when Nabonidus, the king of Babylon, excavated a temple floor that was thousands of years old. During early Roman periods, Julius Caesar's men looted bronze artifacts, and by the medieval period, Europeans had begun digging up pots that had partially emerged from erosion, and weapons that had turned up on farmlands. Antiquarians excavated burial mounds in North America and North-West Europe, which sometimes involved destroying artifacts and their context, losing information about subjects from the past. Meticulous and methodical archaeological excavation took over from
antiquarian An antiquarian or antiquary () is an fan (person), aficionado or student of antiquities or things of the past. More specifically, the term is used for those who study history with particular attention to ancient artifact (archaeology), artifac ...
barrow-digging around the early to mid-nineteenth century and is still being perfected today. The most dramatic change that occurred over time is the amount of recording and care taken to ensure preservation of artifacts and features. In the past, archaeological excavation involved random digging to unearth artifacts. Exact locations of artifacts were not recorded, and measurements were not taken. Modern archaeological excavation has evolved to include removal of thin layers of sediment sequentially and recording of measurements about artifacts' locations in a site.


There are two basic types of modern archaeological excavation: # Research excavation – when time and resources are available to excavate the site fully and at a leisurely pace. These are now almost exclusively the preserve of academics or private societies who can muster enough volunteer labour and funds. The size of the excavation can also be decided by the director as it goes on. # Development-led excavation – undertaken by professional archaeologists when the site is threatened by building development. This is normally funded by the developer, meaning that time pressure is present, as well as its being focused only on areas to be affected by building. The workforce involved is generally more skilled, however, and pre-development excavations also provide a comprehensive record of the areas investigated.
Rescue archaeology Rescue archaeology, sometimes called commercial archaeology, preventive archaeology, salvage archaeology, contract archaeology, developer-funded archaeology or compliance archaeology, is state-sanctioned, archaeological survey and excavation carr ...
is sometimes thought of as a separate type of excavation but in practice tends to be a similar form of development-led practice. Various new forms of excavation terminology have appeared in recent years such as
Strip map and sample Strip map and sample is a method of archaeological excavation applied in the United Kingdom to preserve archaeological remains by record in the face of development threat. It involves machine stripping of an area, plotting observed features onto a ...
some of which have been criticized within the profession as jargon created to cover up for falling standards of practice.

Development-led archaeology

There are two main types of trial excavation in professional archaeology both commonly associated with development-led excavation: the test pit or trench and the watching brief. The purpose of trial excavations is to determine the extent and characteristics of archaeological potential in a given area before extensive excavation work is undertaken. This is usually conducted in development-led excavations as part of
Project management Project management is the process of leading the work of a team to achieve all project goals within the given constraints. This information is usually described in project documentation, created at the beginning of the development process. T ...
planning. The main difference between
Trial trenching Trial trenching is a rapid and relatively inexpensive method of archaeological evaluation used to estimate the archaeological potential of a site. Trenches are located at intervals across a site leaving the rest untouched. A mechanical excavator i ...
watching brief In British archaeology a watching brief is a method of preserving archaeological remains by record in the face of development threat. An archaeologist is employed by the developer to monitor the excavation of foundation and service trenches, lan ...
s is that trial trenches are actively dug for the purpose of revealing archaeological potential whereas
watching brief In British archaeology a watching brief is a method of preserving archaeological remains by record in the face of development threat. An archaeologist is employed by the developer to monitor the excavation of foundation and service trenches, lan ...
s are cursory examination of trenches where the primary function of the trench is something other than archaeology, for example a trench cut for a gas pipe in a road. In the US, a method of evaluation called a Shovel test pit is used which is a specified half meter square line of trial trenches dug by hand.


Site formation

Archaeological material tends to accumulate in events. A gardener swept a pile of soil into a corner, laid a gravel path or planted a bush in a hole. A builder built a wall and back-filled the trench. Years later, someone built a pigsty onto it and drained the pigsty into the nettle patch. Later still, the original wall blew over and so on. Each event, which may have taken a short or long time to accomplish, leaves a
context Context may refer to: * Context (language use), the relevant constraints of the communicative situation that influence language use, language variation, and discourse summary Computing * Context (computing), the virtual environment required to s ...
. This layer cake of events is often referred to as the archaeological sequence or record. It is by analysis of this sequence or record that excavation is intended to permit interpretation, which should lead to discussion and understanding. The prominent processual archaeologist Lewis Binford highlighted the fact that the archaeological evidence left at a site may not be entirely indicative of the historical events that actually took place there. Using an ethnoarchaeological comparison, he looked at how hunters amongst the Nunamiut Iñupiat of north central
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...
spent a great deal of time in a certain area simply waiting for prey to arrive there, and that during this period, they undertook other tasks to pass the time, such as the carving of various objects, including a wooden mould for a mask, a horn spoon and an ivory needle, as well as repairing a skin pouch and a pair of caribou skin socks. Binford notes that all of these activities would have left evidence in the archaeological record, but that none of them would provide evidence for the primary reason that the hunters were in the area; to wait for prey. As he remarked, waiting for animals to hunt "represented 24% of the total man-hours of activity recorded; yet there is no recognisable archaeological consequences of this behaviour. No tools left on the site were used, and there were no immediate material "byproducts" of the "primary" activity. All of the other activities conducted at the site were essentially boredom reducers."


In archaeology, especially in excavating,
stratigraphy Stratigraphy is a branch of geology concerned with the study of rock layers ( strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...
involves the study of how deposits occurs layer by layer. It is largely based on the Law of Superposition. The Law of Superposition indicates that layers of sediment further down will contain older artifacts than layers above. When archaeological finds are below the surface of the ground (as is most commonly the case), the identification of the context of each find is vital to enable the archaeologist to draw conclusions about the site and the nature and date of its occupation. It is the archaeologist's role to attempt to discover what contexts exist and how they came to be created. Archaeological stratification or sequence is the dynamic superimposition of single units of stratigraphy or contexts. The context (physical location) of a discovery can be of major significance. Archaeological context refers to where an artifact or feature was found as well as what the artifact or feature was located near. Context is important for determining how long ago the artifact or feature was in use as well as what its function may have been. The cutting of a pit or ditch in the past is a context, whilst the material filling it will be another. Multiple fills seen in section would mean multiple contexts. Structural features, natural deposits and
inhumation Burial, also known as interment or inhumation, is a method of final disposition whereby a dead body is placed into the ground, sometimes with objects. This is usually accomplished by excavating a pit or trench, placing the deceased and objec ...
s are also contexts. By separating a site into these basic, discrete units, archaeologists are able to create a chronology for activity on a site and describe and interpret it. Stratigraphic relationships are the relationships created between contexts in time representing the chronological order they were created. An example would be a ditch and the back-fill of said ditch. The relationship of "the fill" context to the ditch "cut" context is "the fill" occurred later in the sequence, i.e., you have to dig a ditch first before you can back-fill it. A relationship that is later in the sequence is sometimes referred to as "higher" in the sequence and a relationship that is earlier "lower" though the term ''higher'' or ''lower'' does not itself imply a context needs to be physically higher or lower. It is more useful to think of this ''higher'' or ''lower'' term as it relates to the contexts position in a Harris matrix, which is a two-dimensional representation of a site's formation in space and time. Understanding a site in modern archaeology is a process of grouping single contexts together in ever larger groups by virtue of their relationships. The terminology of these larger clusters varies depending on practitioner, but the terms interface, sub-group, group and land use are common. An example of a sub-group could be the three contexts that make up a burial: the grave cut, the body and the back-filled earth on top of the body. In turn sub-groups can be clustered together with other sub-groups by virtue of their stratigraphic relationship to form groups which in turn form " phases". A sub-group burial could cluster with other sub-group burials to form a cemetery or burial group which in turn could be clustered with a building such as church to produce a "phase." A less rigorously defined combination of one or more contexts is sometimes called a feature.


Phase is the most easily understood grouping for the layman as it implies a near contemporaneous Archaeological horizon representing "what you would see if you went back to a specific point in time". Often but not always a phase implies the identification of an occupation surface "old ground level" that existed at some earlier time. The production of phase interpretations is one of the first goals of stratigraphic interpretation and excavation. Digging "in phase" is not quite the same as phasing a site. Phasing a site represents reducing the site either in excavation or post-excavation to contemporaneous horizons whereas "digging in phase" is the process of stratigraphic removal of archaeological remains so as not to remove contexts that are earlier in time "lower in the sequence" before other contexts that have a latter physical stratigraphic relationship to them as defined by the law of superposition. The process of interpretation in practice will have a bearing on excavation strategies on site so "phasing" a site is actively pursued during excavation where at all possible and is considered good practice.


Excavation initially involves the removal of any topsoil. A strategy for sampling the contexts and features is formulated which may involve total excavation of each feature or only portions.

Stratigraphic excavation

In stratigraphic excavation, the goal is to remove some or, preferably, all archaeological deposits and features in the reverse order they were created and construct a Harris matrix as a chronological record or "sequence" of the site. This Harris matrix is used for interpretation and combining contexts into ever larger units of understanding. This stratigraphic removal of the site is crucial for understanding the chronology of events on site. Stratigraphic excavation involves a process of cleaning or "troweling back" the surface of the site and isolating contexts and edges which are definable as either: # Discrete, discernible "edges" that are formed by being completely separated from the surrounding surface and therefore stratigraphically later than its surroundings # Discrete, discernible "edges" (as in 1.) and have boundaries dictated by the limit of excavation Following this preliminary process of defining the context, it is then recorded and removed. Often, owing to practical considerations or error, the process of defining the edges of contexts is not followed and contexts are removed out of sequence and un-stratigraphically. This is called "digging out of phase". It is not good practice. After removing a context or if practical a set of contexts such as the case would be for features, the "isolate and dig" procedure is repeated until no man made remains are left on site and the site is reduced to
natural Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans ar ...

Tools and techniques

Mechanical excavation

This describes the use in excavations of various types and sizes of machines from small backhoes to heavy duty earth-moving machinery. Machines are often used in what is called salvage or rescue archaeology in developer-led excavation when there are financial or time pressures. Using a mechanical excavator is the quickest method to remove soil and debris and to prepare the surface for excavation by hand, taking care to avoid damaging archaeological deposits by accident or to make it difficult to identify later precisely where finds were located. The use of such machinery is often routine (as it is for instance with the British archaeological television series ''
Time Team ''Time Team'' is a British television programme that originally aired on Channel 4 from 16 January 1994 to 7 September 2014. It returned online in 2022 for two episodes released on YouTube. Created by television producer Tim ...
'') but can also be controversial as it can result in less discrimination in how the archaeological sequence on a site is recorded. One of the earliest uses of earth-moving machinery was at Durrington Walls in 1967. An old road through the henge was to be straightened and improved and was going to cause considerable damage to the archaeology. Rosemary Hill describes how Geoffrey Wainwright "oversaw large, high-speed excavations, taking bulldozers to the site in a manner that shocked some of his colleagues but yielded valuable if tantalising information about what Durrington had looked like and how it might have been used." Machines are used primarily to remove modern
overburden In mining, overburden (also called waste or spoil) is the material that lies above an area that lends itself to economical exploitation, such as the rock, soil, and ecosystem that lies above a coal seam or ore body. Overburden is distinct from tai ...
and for the control of spoil. In British archaeology mechanical diggers are sometimes nicknamed "big yellow trowels".


Archaeological excavation is an unrepeatable process, since the same area of the ground cannot be excavated twice. Thus, archaeology is often known as a destructive science, where you must destroy the original evidence in order to make observations. To mitigate this, highly accurate and precise digital methods can be used to record the excavation process and its results.

Single context recording system

Single context recording Single context recording was initially developed by Ed Harris and Patrick Ottaway in 1976, from a suggestion by Laurence Keen. It was further developed by the Department of Urban Archaeology (Museum of London) from where it was then exported, in ...
was developed in the 1970s by the
museum of London The Museum of London is a museum in London, covering the history of the UK's capital city from prehistoric to modern times. It was formed in 1976 by amalgamating collections previously held by the City Corporation at the Guildhall Museum (fou ...
(as well as earlier in Winchester and York) and has become the de facto recording system in many parts of the world and is especially suited to the complexities of deep
urban archaeology Urban archaeology is a sub discipline of archaeology specializing in the material past of towns and cities where long-term human habitation has often left a rich record of the past. In modern times, when someone talks about living in a city, the ...
and the process of Stratification. Each excavated context is given a unique "context number" and is recorded by type on a context sheet and perhaps being drawn on a
plan A plan is typically any diagram or list of steps with details of timing and resources, used to achieve an objective to do something. It is commonly understood as a temporal set of intended actions through which one expects to achieve a goal. ...
and/or a section. Depending on time constraints and importance contexts may also be photographed, but in this case a grouping of contexts and their associations are the purpose of the photography. Finds from each context are bagged and labeled with their context number and site code for later cross-reference work carried out post-excavation. The height above sea level of pertinent points on a context, such as the top and bottom of a wall are taken and added to plans sections and context sheets. Heights are recorded with a
dumpy level A level is an optical instrument used to establish or verify points in the same horizontal plane in a process known as levelling, and is used in conjunction with a levelling staff to establish the relative height levels of objects or marks. It is ...
or total station by relation to the site temporary benchmark (abbr. T.B.M). Samples of deposits from contexts are sometimes also taken, for later environmental analysis or for scientific dating.

Digital recording

Digital tools used by field archaeologists during excavation include GPS, tablet computers, relational databases, digital cameras, 3d
laser scanner Laser scanning is the controlled deflection of laser beams, visible or invisible. Scanned laser beams are used in some 3-D printers, in rapid prototyping, in machines for material processing, in laser engraving machines, in ophthalmological las ...
s, and unmanned aerial vehicles. After high quality digital data have been recorded, these data can then be shared over the internet for open access and use by the public and archaeological researchers. Digital imaging or digital image acquisition is
digital photography Digital photography uses cameras containing arrays of electronic photodetectors interfaced to an analog-to-digital converter (ADC) to produce images focused by a lens, as opposed to an exposure on photographic film. The digitized image ...
, such as of a physical scene or of the interior structure of an object. The term is often used to include the processing, compression, storage, printing, and display of the images.

Finds processing

Finds and artifacts that survive in the archaeological record are retrieved in the main by hand and observation as the context they survive in is excavated. Several other techniques are available depending on suitability and time constraints. Sieving and flotation is used to maximize the recovery of small items such as small shards of pottery or flint flakes.


Flotation is a process of retrieval that works by passing spoil onto the surface of water and separating finds that float from the spoil which sinks, this is especially suited to the recovery of environmental data such as seeds and small bones. Not all finds retrieval is done during excavation and some especially flotation may take place post-excavation from samples taken during excavation.


The use of sieving is more common on research-based excavations where more time is available. Some success has been achieved with the use of cement mixers and bulk sieving. This method allows the quick removal of context by shovel and mattock yet allows for a high retrieval rate. Spoil is shoveled into cement mixers and water added to form a slurry which is then poured through a large screen mesh.

Spot Dating

One important role of finds retrieval during excavation is the role of specialists to provide
spot dating Spot or SPOT may refer to: Places * Spot, North Carolina, a community in the United States * The Spot, New South Wales, a locality in Sydney, Australia * South Pole Traverse, sometimes called the South Pole Overland Traverse People * Spot (prod ...
information on the contexts being removed from the archaeological record. This can provide advance warning of potential discoveries to come by virtue of residual finds redeposited in contexts higher in the
sequence In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is called ...
(which should be coming offsite earlier than contexts from early eras and phases). Spot dating also forms part of a confirmation process, of assessing the validity of the working hypothesis on the phasing of site during excavation. For example, the presence of an anomalous
medieval In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...
pottery sherd in what was thought to be an Iron Age ditch feature could radically alter onsite thinking on the correct strategy for digging a site and save a lot of information being lost due to incorrect assumptions about the nature of the deposits which will be destroyed by the excavation process and in turn, limit the sites potential for revealing information for post-excavation specialists. Or anomalous information could show up errors in excavation such as "undercutting". Dating methodology in part relies on accurate excavation and in this sense the two activities become interdependent.

See also

Archaeological field survey In archaeology, survey or field survey is a type of field research by which archaeologists (often landscape archaeologists) search for archaeological sites and collect information about the location, distribution and organization of past human ...
* Archaeological plan * Archaeological section * Cut (archaeology) * Feature (archaeology) * Forensic archaeology * Relationship (archaeology) *
Spit (archaeology) In the field of archaeology, a spit is a unit of archaeological excavation with an arbitrarily assigned measurement of depth and extent. It is a method of excavation employed without regard to the archaeological stratigraphy that may (or may not) ...


* Barker, Philip (1993) ''Techniques of archaeological excavation'', 3rd ed., London : Batsford, * Westman, Andrew (Ed.) (1994) ''Archaeological site manual'', 3rd. ed., London : Museum of London,

Further reading

* Corrado Pedeli and Stefano Pulga (2013). ''Conservation Practices on Archaeological Excavations: Principles and Methods'', Los Angeles: Getty Publications, *
Sharon Sullivan Sharon Sullivan is an Australian archaeologist, advocate of Indigenous Australian rights, and author of five books on heritage management. She is best known for her work in establishing protocols and programs for cultural heritage management i ...
and Richard Mackay (2013). ''Archaeological Sites: Conservation and Management'', Los Angeles: Getty Publications,

External links

Adrian Chadwick – Archaeology at the Edge of Chaos: Further Towards Reflexive Excavation MethodologiesPrinciples of Archaeological Stratigraphy and Practices of Archaeological Stratigraphy as authorised free PDFReuben Thorpe – Which way is up? Context formation and transformation: The life and deaths of a hot bath in BeirutRecord Checking Guidance for Anglo-Lebanese Excavations in BeirutSite Phasing and Higher order grouping guidelines for Anglo-Lebanese Excavations in Beirut

Hammer, F. – Post Excavation Manual
*NIOSH Safety and Health Topic
Trenching and Excavation

Excavations at the Roman city of Sanisera, Menorca, Spain
{{DEFAULTSORT:Excavation (Archaeology) Methods in archaeology Articles containing video clips