Sunday 16th October 2016
We made a return to Brimelow this week to extend the survey we carried out last time on the area near the duck pond. It’s quite rare to have a land owner, who is not only will to let you on his land, but is enthusiastic about what you are doing. So we are very appreciative of Roy Brandon, the farmer, for always allowing us full access to his fields (despite the presence of horses who, as you can see, showed great interest in our work).Our survey last time in this area had detected a large linear reading at a depth of between 50cm and 80cm on the east side. It appeared to run roughly parallel to the projected line of the Roman road but a few metres away from it. We wanted to see if this feature continued or developed into something bigger. The results showed a continuation of the feature albeit with gaps. Roy has indicated that he is quite willing to let us excavate to determine what this feature represents. As the season is getting late, this will probably be arranged for next year.
Sunday 28th May 2016
This week we took the Ground Penetrating Radar equipment (kindly loaned to us by Sygma Solutions) to Brimelow Farm. This was to try our newly acquired geophysics skills on the area where we had discovered the Roman road in 2004. It may seem a futile exercise to use the machine on a site where we already know there are the remains of the road. It would, however, be very useful to know whether this technique is able to detect this type of feature in clay-soil conditions where resistivity proved to be totally ineffective. These conditions are also generally detrimental to the GPR system, but maybe the stony surface of the road might provide a good target for the radar to reflect off.
The two fields we have investigated over the years at Brimelow, lie at the north end of Gidlow Lane and straddling the boundary between Wigan and Standish. Despite developer pressure, the farmer, Roy Brandon, has managed to retain the area free from encroaching housing development. However no one knows how long the situation will last as these fields are prime targets for the relentless spread of urbanisation on the outskirts of Wigan.We decided to target the south field with the GPR as this was the one we had particular problems with resistivity. Our excavation in 2004 revealed the road in an area to the south of the pond, where the increased depth of plough soil seemed to give it better protection to the remnants of the road. We therefore planned our GPR survey just south of the previous dig site. Before starting this, however, Roy had told us about an area next to his duck pond where he had observed a square shaped pattern emerge during a dry spell a few years ago. Within the square he had also seen a round feature. This was quite intriguing as there is nothing showing on earlier maps in this area. We therefore decided to explore this region first, as it was easy enough to mark out (especially as I was struggling to re-establish our baseline from 12 years ago). The original baseline, which ran from the corner of the allotment in front of Gidlow New Houses to the apex on the gable of the sheltered housing to the south of the site, was first established in the mid 80’s. The problem, of course, is that over the years trees have grown and various obstacles have appear along the sight line, making it really difficult to re-establish the line, but it is essential if we want to relate our findings to previous work.
Our first surveys (a 10m x 10m and a 10m x 20m) on the site next to the duck pond did not reveal the shapes describe by the farmer. However it did show a large linear reading at a depth of between 50cm and 80cm which would be well worth investigating at some point in the future.
Our second survey over the Roman road site (once I’d got a fix on the baseline) did produce some intriguing results (see below) at various depths of between 60cm and 80cm. A very thin feature, running perpendicular to our baseline, looks suspiciously like a field drain. One of the main readings, however, a large reflection in the centre of the scan, looks to be on the right alignment and wide enough to represent the road. This is great news as it suggests that we may be able rely on GPR for other sites with this type of soil condition.