Responsible Metal Detecting

Metal detectors are tools which can be used to help find metals. They can be used to search for items on the grounds surface and also metal items that are buried in the ground.

They work as an electrical current is passed through a transmitter coil which then generates an alternating magnetic field. If buried metal is detected, this field will be distorted, which will result in an electrical signal being picked up by the receiver coil.

Features and objects within the ground which are not made from metal can sometimes be detected also. Pits, ditches and walls can be found with a metal detector due to their differing levels of magnetism when compared with the surrounding soil.

Metal detecting and archaeology

Metal detecting can be a useful tool within an organised archaeological excavation, as well as by keen amateurs with an interest in the material past.

On an excavation, metal detectors can be used before the dig, as part of the initial survey of the site alongside other forms of geophysical survey. They can also be utilised to search spoil dumps for any missed finds.

Responsible Detecting

Metal detectors and their use have sometimes gained bad attention due to a few irresponsible users. Professional archaeologists sometimes draw attention to the way they have been used by some without recognition of the potential disturbance they can cause to the historic environment. A common fear is that metal detector users may illegally walk and dig on land without permission, or even vandalise sites through their actions. Also, any discoveries made may not be recorded properly, resulting in potentially important or interesting information being lost. Ensuring we know the archaeological context of artefacts, e.g. where it was found, is an important issue, as any unstratified and unrecorded finds offer less information.

However, by thinking ahead and following the recommended code of practice, the use of metal detectors can be extremely successful, and can account for thousands of finds being made each year by the public.

Support

There are a number of organisations who aim to facilitate and improve the responsible reporting and recording of finds. They all offer a wealth of information on their websites.

The Portable Antiquities Scheme is a voluntary scheme which aims to record those archaeological finds discovered by the public in England and Wales. The scheme recognises the importance these finds can make for the understanding of our past.

The Council for British Archaeology is a charitable body. Their aims are to educate and involve people within archaeology and promote the correct care of historic and heritage sites.

The National Council for Metal Detecting is a representative body of volunteers, formed to provide responsible metal detector users with a forum to meet and share information about their hobby. The council has been recognised by the Government as a body which will represent the responsible finding of archaeological remains by its members.

The Code of Conduct

This code is a list of voluntary practices to best ensure the responsible use of metal detectors and the recording and treatment of any subsequent finds. These guidelines should also help you get the best from your metal detecting. To ensure you are being responsible in your metal detecting:

Things to keep in mind before you go metal detecting

1.Ensuring you are not trespassing; before you start detecting obtain permission to search from the landowner/occupier, regardless of the status, or perceived status, of the land. Remember that all land has an owner. To avoid subsequent disputes it is always advisable to get permission and agreement in writing first regarding the ownership of any finds subsequently discovered

2. Adhering to the laws concerning protected sites (e.g. those defined as Scheduled Monuments or Sites of Special Scientific Interest: you can obtain details of these from the owner/occupier, Finds Liaison Officer, Historic Environment Record/Sites and Monuments Record. Take extra care when detecting near protected sites: for example, it is not always clear where the boundaries lie on the ground.

3. You are strongly recommended to join a metal-detecting club or association that encourages co-operation and responsive exchanges with other responsible heritage groups.

4. Familiarising yourself with and following current conservation advice on the handling, care and storage of archaeological objects.

While you are metal detecting:

5. Wherever possible working on ground that has already been disturbed (such as ploughed land or that which has formerly been ploughed), and only within the depth of ploughing. If detecting takes place on undisturbed pasture, be careful to ensure that no damage is done to the archaeological value of the land, including earthworks.

6. Minimising any ground disturbance through the use of suitable tools and by reinstating any excavated material as neatly as possible. Endeavour not to damage stratified archaeological deposits.

7. Recording find spots as accurately as possible for all finds (i.e. to at least 100m², using an Ordnance Survey map or hand-held Global Positioning Systems (GPS) device) whilst in the field. Bag finds individually and record the National Grid Reference (NGR) on the bag. Find spot information should not be passed on to third parties without the agreement of the landowner/occupier (see also clause 9).

8. Respecting the Country Code (leave gates and property as you find them and do not damage crops, frighten animals or disturb ground-nesting birds, and dispose properly of litter.

After you have been metal detecting:

9. Reporting any finds to the relevant landowner/occupier; and (with the agreement of the landowner/occupier) to the Portable Antiquities Scheme, so the information can pass into the local Historic Environment Record/Sites and Monuments Record. Both the Country Land and Business Association and the National Farmers Union support the reporting of finds.

10. Abiding by the provisions of the Treasure Act and Treasure Act Code of Practice, wreck law and export licensing. If you need advice your local Finds Liaison Officer will be able to help you.

11. Seeking expert help if you discover something large below the ploughsoil, or a concentration of finds or unusual material, or wreck remains, and ensuring that the landowner/occupier's permission is obtained to do so. Your local Finds Liaison Officer may be able to help or will be able to advise of an appropriate person. Reporting the find does not change your rights of discovery, but will result in far more archaeological evidence being discovered.

12. Calling the Police, and notifying the landowner/occupier, if you find any traces of human remains.

13. Calling the Police or HM Coastguard, and notifying the landowner/occupier, if you find anything that may be a live explosive: do not use a metal detector or mobile phone nearby as this might trigger an explosion. Do not attempt to move or interfere with any such explosives.

This code has been sourced from the Portable Antiquities Scheme.

Information compiled by Elizabeth Faley.

15th century silver groats and pennies discovered by metal detecting and now in Craven Museum & Gallery's collection

15th century silver groats and pennies discovered by metal detecting and now in Craven Museum & Gallery's collection

Post-medieval silver cufflinks found by metal detecting and now in Craven Museum & Gallery's collection

Post-medieval silver cufflinks found by metal detecting and now in Craven Museum & Gallery's collection

A silver medieval brooch from Craven Museum & Gallery's collection, found by metal detecting

A silver medieval brooch from Craven Museum & Gallery's collection, found by metal detecting