An Overview of Excavation Methods

Different methods of excavation can be applied to different sites for many overlapping reasons. Test-pitting, trench excavation, and open-area excavation can be used alone or in conjunction to best fit the needs and constraints of a particular site. Crucially, they should be chosen to best answer the questions that are the reason behind excavating. 

Test-pitting usually involves small, strategically placed square trenches that reveal more than surface fieldwork and basic shovel-testing. They are mainly used for revealing the basic stratigraphy and depth of deposits, with minimal disturbance to the overall site.¹ As one of the most accessible forms of excavation, it is not only a useful first stage, but can allow the public’s involvement. For example, the Epiacum Roman Fort Test-Pitting Project in 2017, which set out one of its objectives as an exercise in getting the local community interested in archaeology.² 

However, test-pitting alone may not give a complete picture of a site. In their article for American Antiquity, J.D. Nance and B.F. Ball collated data from various excavation techniques. They found test-pitting was more useful in larger sites with higher artefact density, with intersections and the distribution greatly affecting the overall picture.³ In cases where there are constraints in place (for example ethical regulations when excavating indigenous artefacts, or in tricky terrain), test-pitting cannot be implemented as ideally as the strategy would like.⁴

The trench excavation method involves long and shallow pits, dug into the earth with supporting baulks on either side. It provides a more in-depth view of larger sites, and is useful to determine the general layout and distribution before larger open-area excavations. For these reasons, it is used in commercial archaeology contexts.⁵ As they cover more ground, evaluation trenches can provide a clearer picture of the distribution of artefacts. One of the main downsides of this method lies in the constraints of the baulks, and the spacing between them. Without adequate planning, features may go unnoticed.⁶

Lastly there is open-area excavation. It can provide the fullest picture of an area, as it completely uncovers each layer of the site. It is the highest level of disturbance,  and should ideally be used if less-destructive methods cannot show the full picture. Open-area excavation also requires a lot of labour and budget, and is constrained by the environment surrounding the site, working best in open, flat terrains, such as the areas of northern Europe where the technique was developed.⁷

No method is in itself superior to the others, and many times test-pitting, trenches, and open-area excavation are used in conjunction with each other.⁸ The key aspect to choosing a strategy for excavation is to carefully balance the location, environmental conditions, resources, safety, ethics, and other constraints with a central question that the excavation should be answering. Most importantly, is to have done the upfront work of non-invasive research like fieldwork, and geophysical surveys (amongst others) to set up a strong strategy before a shovel hits the earth.

This was written for the first assignment on the short course Archaeology in Practice. I chose the following prompt: “How might the different approaches of test-pitting, trenches and open-area excavation be applied to sites of varying size and character?”.

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1. Kevin Greene and Tom Moore, Archaeology: An Introduction (Abingdon: Routledge, 2010), p. 96. ↩︎
2. Rob Young, ‘Report on Archaeological Test Pitting at Epiacum Roman Fort’, Epiacum Heritage, 1 October 2017 <https://www.epiacumheritage.org/wp-content/uploads/2018/01/Epiacum-Test-Pitting-Report-2017.pdf&gt; [accessed 24 February 2025]. ↩︎
3. Jack D. Nance and Bruce F. Ball, ‘No Surprises? The Reliability and Validity of Test Pit Sampling’, American Antiquity, 51 (1986), pp.457-461, doi:10.2307/281747. ↩︎
4.  Amy Mosig Way, ‘Test-pitting and the detection of sub-surface sites: an
   example from Lake George, NSW’, Australian Archaeology, 83.1 (2017), doi: 10.1080/03122417.2017.1307317. ↩︎
5. Green and Moore, Archaeology: An Introduction, p.96 ↩︎
6. Philip Verhagen and Arno Borsboom, ‘The Design of Effective and Efficient Trial Trenching Strategies for Discovering Archaeological Sites’, Journal of Archaeological Science, 36.8 (2009), p.1807, doi:10.1016/j.jas.2009.04.010. ↩︎
7. Green and Moore, Archaeology: An Introduction, p.97 ↩︎
8. Francis P. McManamon, ‘Discovering Sites Unseen’, Advances in Archaeological Method and Theory, 7 (1984), p.223, doi:10.1016/B978-0-12-003107-8.50009-8. ↩︎

Bibliography

Greene, Kevin and Tom Moore, Archaeology: An Introduction (Abingdon: Routledge, 2010).

Higginbotham, Edward, ‘Excavation Techniques in Historical Archaeology’, Australian Journal of Historical Archaeology, 3 (1985), <http://www.jstor.org/stable/29543138&gt; [accessed 24 February 2025].

McManamon, Francis P., ‘Discovering Sites Unseen’, Advances in Archaeological Method and Theory, 7 (1984), <https://doi.org/10.1016/B978-0-12-003107-8.50009-8&gt; [accessed 24 February 2025].

Mosig Way, Amy, ‘Test-pitting and the detection of sub-surface sites: an example from Lake George, NSW’, Australian Archaeology, 83.1 (2017), <https://doi.org/10.1080/03122417.2017.1307317&gt; [accessed 24 February 2025].

Nance, Jack D. and Bruce F. Ball, ‘No Surprises? The Reliability and Validity of Test Pit Sampling’, American Antiquity, 51 (1986), <https://doi.org/10.2307/281747&gt; [accessed 24 February 2025].

Rob Young, Epiacum Heritage, Report on Archaeological Test Pitting at Epiacum Roman Fort (2017). <https://www.epiacumheritage.org/wp-content/uploads/2018/01/Epiacum-Test-Pitting-Report-2017.pdf&gt; [accessed 24 February 2025].

Verhagen, Philip and Arno Borsboom, ‘The Design of Effective and Efficient Trial Trenching Strategies for Discovering Archaeological Sites’, Journal of Archaeological Science, 36.8 (2009), <https://doi.org/10.1016/j.jas.2009.04.010&gt; [accessed 24 February 2025].