To Excavate or Not To Excavate?

The traditional image of archaeology is that of excavation, or digging!

An archaeological excavation in progress. Excavation of a commoner’s house at the Aztec city of Calixtlahuaca, Mexico. Source Image here.

Indeed, excavation is a key component of archaeological research. It is the principal method of data acquisition in archaeology, involving the systematic uncovering of archaeological remains through the removal of the deposits of soil and the other materials covering them and accompanying them (Renfrew & Bahn 2008: 580).

A problem with archaeological excavation, however, is that it comes at a significant cost!

To give one example, in my last post I talked about the ancient Roman towns of Pompeii and Herculaneum, buried by the eruption of Mt Vesuvius in AD 79.

An exceptional level of preservation has allowed us some remarkable insights into life in the Roman Empire in the first century AD. However, these insights, as well as the economic benefits derived from tourism have come at a price. Excavation has removed the ash that has protected the sites for several hundred years. There is presently much concern about the stability of Pompeii after a series of recent collapses that have occurred as a result of heavy rainstorms.

This highlights a fact that archaeology has slowly come to realise - that the best way of preserving a site is by not excavating it at all - which has led to a more calculated use of archaeological excavation. Predominately nowadays, excavation only occurs when a site is under threat of significant damage or destruction from development projects or natural processes such as erosion along shorelines. Excavation of a site can also be justified by worthwhile research questions. Increasingly, however, technological advances are providing potential non-invasive alternatives to research driven excavation. 

Another reason why excavation is often only undertaken with good justification is because it involves the destruction of archaeological data!

The shabby tweed jacket alone suggested that he was a scholar. The horn-rimmed reading glasses and tousled piles of coffee-stained papers completed the picture. He sat under a dim reading light flipping vaguely through a massive folio of antediluvian age. Dust filtered lightly between his face and the lamp as he turned the pages. I had only watched him for a few moments when I saw him quickly take up a pen and furiously write in a tattered spiral note-book. He put down the pen as quickly as he had taken it up, reached to the top of the page, and tore it from the folio in one rapid motion. He proceeded to take a silver Zippo out of the side pocket of his jacket and light the bottom corner. He held the burning page over a wastebasket until it was fully engulfed, then dropped it in and turned back to the book.

In shock I hurried over to the librarian's carrel. "That man just tore a page out of a book and burned it!" I exclaimed.

The librarian looked up slowly. "Hum," he said, looking enigmatically past me at the man.

"Aren't you going to do anything?" I asked, puzzled at the librarian's disinterested response.

"Oh, it's OK," he said, looking back at me. "He's an archaeologist." 

This anecdote is from Peter Peregrine's book "Archaeological Research: A Brief Introduction", published by Prentice Hall.

As noted by Peregrine (2001: 67), it is a great illustration of one of the "truly odd" facts of archaeology - archaeologists destroy their data as they collect it! 

What is most valuable to an archaeologist is information, such as WHERE an object is found, and what its RELATIONSHIP is to other objects around it - i.e. its CONTEXT. This is the type of information that is most useful to archaeologists trying to understand past human behaviour. A primary interest in the context of objects in the archaeological record, rather than the value of individual objects, is the key difference between archaeology and looting! This is another reason why Indiana Jones is not a good example of an archaeologist!

The data remaining following excavation is only as good as the records made by the archaeologist. Hence the emphasis on meticulous and standardised recording during excavation (standardised methods of archaeological recording are important so as to allow comparisons to be made between sites excavated by different archaeologists!) 

A problem, particularly with larger archaeological sites, is that due to time and/or financial restrictions, it is virtually impossible to record ALL of the potentially useful information about a site. That is, information that could be used to answer ALL of the possible questions that the archaeologist (or other archaeologists) may have about that site in the future. Therefore, some potentially useful information will always be lost forever when a site is excavated, a reason why an excavation should not be taken without good reason! Often, only a part of a larger archaeological site will be excavated - only enough to answer a particular research question or only the part of a site potentially under threat from a development project. This leaves a part of the site for future researchers with other questions.

Sometimes collectors/ 'treasure' hunters/metal detectorists misunderstand that the principal objection to their activities is not due to professional archaeologists jealously guarding potential 'treasures' and the 'prestige' associated with valuable finds, but because the real value of objects to archaeological research is in their context, information that is lost when objects of potential value are dug up and other objects cast aside with little regard!

In New Zealand, the Heritage New Zealand Pouhere Taonga Act 2014 makes it unlawful for any person to modify or destroy the whole or any part of an archaeological site without the prior authority of Heritage New Zealand.  

An archaeological site is defined in the Act as any place in New Zealand (including buildings, structures or shipwrecks) that was associated with pre-1900 human activity, where there is evidence relating to the history of New Zealand that can be investigated using archaeological methods.

I am not familiar with the relevant legislation for other countries, but it is certainly worth being aware of the regulations in your area. 

In a future post I will elaborate on some of the ways that context informs archaeological research!

Thanks for reading,

Nick.

References 

Peregrine, P. N. 2001. Archaeological Research: A Brief Introduction. Upper Saddle River, N. J. : Prentice Hall.

 

Renfrew, C. & Bahn, P. 2008. Archaeology: theories, methods and practice (5^th ed.). London: Thames & Hudson.