Low Borrowbridge Roman Fort
LOW BORROWBRIDGE RECTANGULAR ENCLOSURES
Excavation Report from Spring Dig 2016
The report from OAN from the Easter dig in the fields to the south of the fort is now available. Click below for the full text and the figures in separate PDF files.
September 2016 Excavation Report
Click below for the report on the excavation of the Roman Road in the South Field
Low Borrowbridge Roman Fort 2016 excavation Interim results
Mid-April saw a substantial amount of new work at Low Borrowbridge which we hope will add to our understanding of this important site. The results are now being analysed and full reports will be available shortly. Here is a brief update:
- Geophysical surveys
We completed both magnetometry and resistivity surveys of the southern quarter of the Big Meadow south of the fort down to the Lune, and across the river in the field owned by David and Christine Knipe of High Carlingill (thanks to both the Wilsons and the Knipes for their permission and support and Karl for yet again giving up his own time to help us). Our objective was to find any evidence of an earlier crossing point west of the current Salterwath Bridge. Nothing obvious was found, but the data continue to be analysed.
- Photogrammetric survey
Jamie Quartermaine and Pete Schofield of OAN flew their cameras in a UAV over the whole site. Below is the hillshade plot for Big Meadow (west of Howgill Lane) and Salter field (east of Howgill Lane) to the south of the fort. The level of detail is astonishing, and complements both the LiDAR and geophysical surveys. Traces of a possible holloway can be seen in the top right corner of Salter field, as well as evidence of quarrying in the centre of the Big Meadow. You may be able to spot a circular feature in the centre of the Big Meadow, which might be a kiln.
Jamie and Pete have sent the full version of the survey. The hillshade for the whole area is available as a pdf PhotogrammetryHillshade-All.
We opened three 5m x 2m trenches over the week, two in Salter field (east of Howgill Lane) and one in the Big Meadow across a possible platform found in the geophysics by Karl. The first trench in Salter field was across the northern edge of the large rectangular feature identified last year through geophysical surveys. This proved to be a very substantial ditch, approximately 3m wide and 2 m deep with the infill being used as a bank on the outside. It was so deep that we needed to bring in a mechanical digger to get to the bottom of it for safety reasons. Disappointingly there were no finds in the ditch to help date it (possibly suggesting that the ditch is very early, Roman even) but soil and other organic samples taken from the base of the ditch are now being analysed. The size of the ditch, and the extent of the feature, suggests a substantial effort to create it – whatever was on the inside the people responsible for its creation were keen to keep in rather than keep others out! The second ditch in Salter field was placed over a possible circular feature, but unfortunately nothing was found other than a few sherds of Roman pottery in the topsoil, along with the ubiquitous clay pipes. The excavation in Big Meadow was placed over an interesting looking feature from the geophysical survey. This appears to have been robbed out at some time and an early field drain cut across it.
Pictures of the copter survey undertaken by Jamie and Pete. Pictures were very difficult to capture as the copter zoomed out of range remarkably quickly. Steve managed to capture these lovely images.
Some pictures of the trenches:
Thanks again to OAN staff, Becky, Pete, Karl and Jamie, for all their help, expertise and enthusiasm, and to all the LAS volunteers who helped in one way or another.
Low Borrowbridge Roman Fort 2015 REPORT
Low Borrowbridge Roman Fort 2015
In September, with scheduled ancient monument permission and generous grants from CWAAS and KHAS, we carried out a resistivity and magnetometry survey of the fort platform and selected areas around it. We did the resistivity, using the excellent equipment kindly loaned to us by the Hartleys and Karl Taylor of OAN supervised us, carried out the magnetometry and will analyse the data and produce the report. In the meantime here are the interim results: LBB geophys results . See what you can make of them.
Steve recorded the action:
Low Borrowbridge Roman Fort 2014
Earlier in the Summer of 2013 we were able to get, free of charge, LiDAR surveys covering both the Low Borrowbridge and Raisbeck areas. While at a fairly low level of resolution the surveys proved intriguing and opened up a number of avenues of further exploration (see notes above/below from Jan, Andrew and Judith).
The LIDAR image for the area around Low Borrowbridge is shown below, clearly showing the fort platform and the Brockholes site (see page below).
In April 2014 we began the geophysical survey on the site of the probable vicus (the field south of the fort north of the river. Conditions were not ideal (!) as the ground was very wet. The experts at OAN advised use of magnetometry which is good at picking up areas of burning (possible hearths and industrial activity) as well as ditches, roads etc. The results are shown below:
Interpreting the results is a real art (!) and takes an expert eye, so thanks to Karl Taylor of OAN who has annotated the plot. There seems to be a lot going on in the field, not all of it Roman of course. So much so that we are now planning a further two days of surveying using resistivity (better suited to finding walls, building foundations and such like) when the ground is drier in July.
Graham Hooley, June 2014
Resistivity July 2014
Following on from the magnetometry survey a full resistivity survey was undertaken over the same area. While magnetometry relies on changes in magnetic fields (typically produced by burning, as in hearths or industrial activity, or by ditch infill with material on different magnetic alignments), resistivity identifies changes in resistance to an electric current passed through the ground. This is particularly good at identifying stone structures and ditches. The former create high resistance to the current, the latter low resistance.
The resistivity survey was conducted over two days – 18th and 19th July 2014. Preliminary analysis produced the plot below.
As with magnetometry the plot requires expert analysis to interpret! Dark areas indicate high levels of resistance to the current, while light areas indicate low resistance. Of course, as well as stone features natural rock also produces high resistance, and natural channels will show up as low resistance. So the features identifiable above could be archaeology or natural – see what you can make out! Karl Taylor from OAN will be undertaking further digital refinement of the plot and providing an expert interpretation in due course.
Many thanks to all members who came along to help, and to Steve King who took the photos below and provided the captions! A very special thanks goes to Karl Taylor of OAN who led the work. We only had one day left in our budget, but Karl kindly came along on Saturday, his day off from working for OAN, to finish the job. That was above and beyond the call of duty and very much appreciated by all.
Graham Hooley and Steve King (photos) July 2014
Resistivity plot Oxford Archaeology North
Geophysics Report November 2014
We now have the report from OAN. To download your own PDF copy click this link : Geophysical Survey Report
The surveys appear to show a lot of activity on the field as might be expected with an area that has had such an important position in the landscape for so long. The next step is to try to find out what it all means!