Metal detecting and archaeology in England

Archaeologists have long been divided over the effects of metal detecting. Some see the hobby as predominantly harmful, while others have embraced the metal detector as an invaluable aid to investigation of the past. This debate has been inconclusive, not least because of a lack of basic information on which reasoned judgements might be made. Metal detecting and archaeology in England, a rapid survey commissioned from the Council for British Archaeology in November 1993, attempted to take matters forward by objectively addressing some of the issues. The broad aims were to provided an outline quantification of the impact of metal detecting on archaeological sites in England, and to assess the metal detector's overall contribution to archaeological knowledge.

The report was published in January 1995, and considered a number of basic themes:

the technical characteristics of metal detectors, their potential for artefact recovery, and the scale and profile of the hobby
the quantity of finds being made, the level of finds reporting, and the quality of information on the provenance of reported finds
the impact of detecting on archaeological projects, and the extent to which detectors are used within archaeology
academic advances made through metal detecting (using case studies)
the broader implications of the survey's findings, variations in the usefulness of metal detectors in different parts of the country, the uneven distribution of metal in the ground, and varying states of preservation of buried metal and of its archaeological context, in different parts of England
illicit detecting on scheduled ancient monuments and excavations

The survey found the metal detector to be an archaeological tool of extreme importance. Within archaeological excavation and fieldwork, detectors have made a large contribution to the understanding of individual sites - not only by the prediction and recovery of artefacts, but through provision of information on site patterning, and the location of diagnostic material that might otherwise have been missed. Although the use of metal detectors by field archaeologists is now widespread, it is also unsystematic and seldom informed by policy. While other forms of remote sensing have been the subject of considerable technical assessment and published study, the body of archaeological literature on metal detecting was found to be small - perhaps because of the controversial reputation of the subject.

Metal detectorists have recovered a huge amount of new material for archaeological research, and metal detectors have been responsible for assisting some major advances in archaeological knowledge. Progress would be even greater if more finds were reported, and the information derived from them was made more readily available. Yet while hundreds of thousands of items are found each year by detectorists, only an extremely small proportion is reported to museums; information about provenance is generally poor, and even where finds are being reported, Sites and Monuments Records and other archaeological bodies are generally not aware of the results.

Improved communication within archaeology is one of the report's seven principal recommendations.
The others are:

To improve liaison, which is at present extremely variable, between archaeology and the detecting community. A national reporting system may eventually be feasible, but progress today depends on local action by archaeologists.
To investigate ways of managing a large increase in the finds referral rate; even at the present low levels of finds reporting, staff at museums have found themselves unable to cope with the workload of processing detectorists' finds, and in most areas a large increase in the referral rate wound be unmanageable.
To investigate new ways of protecting scheduled ancient monuments from illicit detecting; at least 188 scheduled monuments were identified at which illicit detecting is either known to have taken place or is strongly suspected, including sites which have been raided many times. The true extent of illicit detecting is probably much greater and none of the current methods used to protect ancient monuments from illicit detecting is fully satisfactory.
To investigate the relationship between illicit detector finds and the antiquities market. Some archaeological sites are being targeted to supply the antiquities market. The principal role in investigating and countering this problem lies with the police, but there is little indication that the problem is considered a high priority.
To educate archaeologists about the metal detector. Most archaeologists are poorly informed about the technical capabilities and archaeological potential of detectors. Rigorous assessments are needed, including demonstrations and experiments, followed by the rapid publication of results.
To investigate finds erosion in the ploughsoil. More information is needed about the disruption of stratified contexts by ploughing and about the degradation of metal in ploughsoil.
A number of important considerations have emerged from this study. A growing body of evidence suggests that in many ancient societies non-ferrous metal was treated differently from other less valuable materials. Apart from deliberate deposition or accidental loss, metal was not, by and large, casually thrown away, even as scrap; instead it was recycled. Finds made by detectorists therefore probably represent more specialised depositional processes, such as hoarding, casual loss, or votive behaviour, than those underlying the archaeological record as a whole. Metal detecting can therefore do far greater good, and (in the wrong hands) far greater harm, on some types of site than others. In addition, behind the locally uneven pattern of non-ferrous metal distribution lies a nationally uneven pattern, and the causes of these regional variations and trends also deserve study.

The precise nature of the archaeological context requires discussion and clearer definition. Although the integrity of vertical contexts may be disrupted or destroyed by agriculture, a valuable horizontal context often remains even when the vertical context is gone. Closer study of the mobility of material of all kinds in the ploughsoil is required, together with better understanding of the circumstances in which spatial blurring of topsoil assemblages may or may not be taking place. While evidence for the degradation of metal objects in ploughsoil is impressionistic, finds specialists report a noticeable decay in the quality of material over the last decade. Chemical, mechanical, and biological processes appear to be responsible, and may be acting on the material at different rates and in different ways. Better diagnosis and mapping of these processes and their effects are required.

Metal detecting presents archaeology with an intriguing opportunity. If the skills of hobbyists could be more fully harnessed, and their finds properly recorded, the gains to archaeological knowledge would be substantial. Certainly, many of the problems associated with metal detecting are unlikely to be resolved immediately, but it is essential that detectorists and archaeologists work together to find solutions, in order to realise the potential of this vast volume of archaeological material for our understanding of the past, and to maximise the opportunities it presents to help us fully appreciate and properly manage the true richness and diversity of the archaeological resource of this country.