Iron Age archaeological dig: Ballanorris, Isle of Man

The site I'm standing on is Ballinorris which is a site which was known for a very long time and indeed partly excavated by Gerhard Bersu in the 1940s but we've come back to do some more work here because techniques have developed so much since then. I'm working with a team of about 30 people which includes some Manx students and volunteers and students from America and Canada as well as British and Irish students so there's quite a good mix of people both local and from far away. Gerhard Bersu was a very famous German archaeologist who fled to Britain to avoid Nazi persecution and began excavating there in England but then was interned as an enemy alien once war was declared and was sent to the Isle of Man and he negotiated with the support of many British archaeologists to be allowed to excavate on the island and in fact the biggest campaign of excavations that's ever taken place here was by him with volunteers from the internment camps during the war. So here we are 70 years after Bersu carried out his excavations but since that time many techniques have been developed that weren't available to him then. One or two like pollen analysis were known then but he couldn't do them in the war, there weren't the facilities, but most others like radiocarbon dating which allows us to get absolute dates from charcoal and bone and study of soils and environmental evidence such as seeds wasn't available at all and so many techniques to date the site and work out the economy just weren't open to him at all so we've come back to remove some of the bits of the site that he left untouched and leaving others for people in future years to have yet more techniques to apply. Bersu did a very extensive excavation and discovered a ditch, a circular ditch within which was a very large bank and in the centre of the site was what he thought were a series of very large round houses, one built up above another with series of floors and different steps within the buildings. Now these are very unusual now that we know more about Iron Age buildings both on the Isle of Man and across the British Isles and so one of the questions many archaeologists have had is were the buildings really like that so we've come back not only to date the buildings but also to see if they really were of the type that he thought they were. So what we had to do was find the trenches that Bersu had dug out and remove the soil that was in those which was a soil that had been archaeological layers from the Iron Age but which had been dug out by him, made into spoil heaps and then put back in the trenches and it has been quite difficult for us, surprisingly difficult for us to identify the edges of his trenches, remove what has already been disturbed and leave intact what looked like walls but are actually the remaining bits of the mound which are left for us to look at now and that's what we've done. We've removed partly by machine and partly by hand the trenches that he dug with his internees and then filled back in and now we've got the bits of the site left as a sort of pattern of upstanding fragments to try and make sense of what we can see about the site compared to what he saw about it. We've discovered quite a lot of new things already. One of the most interesting is the way in which the layers have built up in the centre of the site. He produced some very nice drawings some of which are in the Banks Museum but we are able to look at the sections with a new light and a new eye with more experience of 70 years of excavating similar sites. Many of the post holes of the site were in his trenches and have been dug away but some of them still survive in the sections and we can see those and we can see parts of hearths and we can see parts of pits which were dug into the layers that had already formed and were then filled in and then covered over by more layers. So the site has a long and complicated history which Bersu couldn't calibrate. He had no way of measuring the length of time so by the time we've taken our samples and sent them off for analysis we will be able to find out how long this site was used as a habitation. We're excavating on two different portions of the site this year. One part is the part that Bersu knew about and which we're re-examining and another part is something he didn't know about at all. We've been doing geophysical survey which is using instruments that measure different magnetism of the ground and reveal where buried buildings and activity areas are in the rest of the field and from that we've located a field system and two circular structures which we're now excavating and again taking samples from those so we'll see whether they are linked in some way to the mound settlement or whether they are completely separate and belong to a completely different period. At the moment the finds are very very few from all the sites so we can't use the finds to associate them but we should be able to associate them through other forms of evidence that we'll get from our analysis. The field system would have been for controlling animals and may have been for marking out fields where they grew crops. We don't yet know what crops they grew here but in many other parts of Britain and Ireland people are growing wheat, barley and oats and so from the samples we take we hope to find out what they were growing here on this part of the Isle of Man and it's likely that these field systems were partly to control the animals and to partly keep them out of the fields with the crops. The soil that builds up over time it reflects in its texture and its colour the sort of activity that creates that deposit so if you have a floor then it will have one sort of texture and colour and if you have a rubbish layer it will have a different colour and if it's a dump of clay to make up a new surface for a new floor it will be different again and so these are all very easy to see when the soil is very damp but as the soil dries out they are more difficult to see and they're easy to feel when you're troweling and digging them you get used to the different textures but we often need to spray down the side of the trench to dampen it down again so the different colours become visible and as you spray it all the different textures and colours come to life in a way that they don't in the dried desiccated surface. The excavation techniques that we apply are fairly standard ones for archaeology in Britain so we're removing the disturbed topsoil by machine and then we clean off very carefully with trowels to reveal the different textures and colours of the soil and then where the soil is human deposits then we excavate those carefully away and take samples from them and so troweling and sometimes brushing are important techniques to allow us to find the features and excavate them and work out how the buildings were put together. After the excavation of the various features and the layers we then have to record them which we do with record forms and drawings which are very carefully measured and recorded on a special film which is archivally stable and then all these records can go to the museum as part of the archive with the samples and any finds that we make and we use surveying equipment to locate where our excavations are and their height above sea level and how they fit into the overall landscape. The samples that we take some go straight off to the lab in carefully sealed bags but other samples are processed here in the field and the soil is washed through with water with running water and then sieved to find fine particles and the remains of charcoal and seeds from the crops that were being grown here so some of the sampling happens here and then it's just those residues that are left over from washing the soil that are sent off to the experts in different parts of the country. It would seem from the excavations that Bearsue did and what he thought was happening and from how we suspect we might reinterpret the site that it was probably one extended family living in the Ballinoris settlement and then probably at the same time or at another time which we'll find out from our analysis a family was living in the settlement that we have newly discovered so we don't have a lot of people living here though the size of the bank and ditch suggests that a lot of people were involved in the construction of the site in the first place so that may say something about the social organisation that they were able to command a large labour force to build the site even though they weren't all then living in it.