Norman coin hoard becomes England's most valuable treasure—it could have been worth a lot more

There is clearly giddy excitement in the shaky footage showing hands scrabbling in the soil in the Chew Valley in south-west England. A close-up shot captures someone pulling silver coin after silver coin from the churned earth as a woman laughs "there's pennies everywhere." The video accompanied news reports in 2019 of the monumental find by seven detectorists of a hoard of silver coins dating from the time of the Norman conquest in the 11th century.

The hoard has just been purchased for a whopping £4.3 million by the South West Heritage Trust. While this might be the largest amount ever paid for such a discovery, as an archaeological scientist I can tell you that much of its historical value was lost the moment it was pulled from the ground.

Such stories of amateur finds are easy to get behind. Detectorists are the underdogs—amateurs who are driven by their passion for the past to spend their free time diligently searching for hidden treasures.

The nation's love of such stories was seized upon in Mackenzie Crook's gently hilarious television show, Detectorists (2014). As reflected in the series, however, metal detecting has a fraught relationship with archaeology.

While both involve digging up remains of the past, the two groups have different opinions on what is most important when it comes to such finds. For archaeologists, the finds themselves are often less important than the context in which they were discovered—the opposite is true for detectorists.

The detectorists in the Chew Valley were acting within the law. They first sought permission from the landowner, and ensured the find was reported to the authorities. However, as the video of the discovery shows, the coins were dug out haphazardly.

Archaeologists would have gone about this in a different way, following a scientific process of excavation and recording. This is because once excavated the contextual information is destroyed forever.

For instance, when speaking about the Chew Valley Hoard on Radio 4's PM program, Professor Michael Lewis, head of the Portable Antiquities Scheme (a voluntary government-run program that records small finds of archaeological interest by members of the public), struggled to answer any specific questions about the circumstances in which the hoard had originally been interred. This is because of the way it had been dug up.

To dig or not to dig?

Archaeology today employs a unique system of excavation, a sort of reverse engineering of the sequence of past events. This comes complete with intensive recording, sampling of soils and other processes designed to minimize the loss of information.

In the case of hoards—deliberately buried caches of valuables from a time before banks and safes—this method of recovery can preserve information about the date of burial and whether the items were deposited in a single episode or over time. It can also help ascertain what organic materials were originally present and even provide insights into the meaning of the objects for those who deposited them.

We saw this sort of process able to take place in 2014 after detectorists found the Galloway Hoard—more than 100 gold, silver, glass, crystal, stone and earthen objects from the Viking age. These amateurs contacted the relevant authorities before digging it up, which meant it was possible, through expert recovery, to reconstruct the precious textiles and other containers in which the objects were originally buried.

Many countries, including Greece, strictly outlaw the use of metal detectors for treasure hunting, although many people continue to do so in secret. In the UK, the hope is that by legalizing reporting and offering purchase of treasure, the finds can at least be preserved for research and for public viewing.

However, there isn't anything in this approach to stop the unscientific method of recovery, which will continue to rob us of much more that we might have known. This leaves the question of whether such finds should even be dug up at all.

Archaeology is a relatively young discipline, but the surviving remains of the distant past are a finite resource. Land development, climate change, mechanized agriculture, population growth, war, looting and desecration are threats facing archaeological sites the world over.

In recent years professional archaeologists have responded by excavating the bare minimum. We might dig ahead of construction works and large infrastructure projects such as HS2. Sometimes we excavate because a site is threatened by coastal erosion or other environmental changes. When we dig purely for the sake of research, or as part of a community project, we focus on partial recovery, prioritizing survey, geophysics and "test-pitting" (a sort of archaeological keyhole surgery).

In all cases we must also ensure that there is enough money to cover the conservation and protection of the things we dig up, and, crucially, publish the reports of their excavation, with all its insight into the context of the finds.

This article is republished from The Conversation under a Creative Commons license. Read the original article.