Initial geophysics results from three of the bloomery sites investigated around Windermere

Colour generated magnetometry plot of High Stott Park bloomery

Colour generated magnetometry plot of High Stott Park bloomery

Here are the initial survey results for the first three bloomery sites to be investigated by us around Windermere. The surveys were undertaken by volunteers who were given enthusiastic supervision by Ian Brooks from Engineering Archaeological Services Ltd.

High Stott Park bloomery had very little earthwork evidence at ground level and the test pitting had revealed slag deposits spread across the field. The magnetomery plot and coloured plot (north to the right) show at least one furnace site on the top left (SW) corner, which on the ground was adjacent to a mossy area of slag deposit. The furnace is shown on the colour plot as an extreme dipolar anomaly (small red blob with dark blue around it). On the right hand side of the plot (NW) there are other anomalies and a messy spread of background noise. It is probable that the bloomery slag mound survives best on this side of the site but the whole earthwork mound was levelled at some point, probably during landscaping of the wider grounds of the nearby farm. There is an edge to the spread slag material shown on the SE corner of the black and white plot and also a linear feature running roughly NNW/SSE.

Magnetometry plot of High Stott Park bloomery

Magnetometry plot of High Stott Park bloomery

The magnetometry at Cinder Nab (north roughly to top) picked up one definite furnace site, which was located on the SW edge of the well-defined earthworks of the slag mound. The dipolar anomaly for the furnace is shown with a black arrow on it. The rest of the material adjacent to is consists of readings from the slag mound itself. Other things to note are the background noise on the left (West) of the colour plot coming from the fence surrounding the tennis courts, and also the complete lack of results from the putative later kiln which was seen as an earthwork on the ground located  immediately NE of the bloomery mound.

Colour generated magnetometry plot of Cinder Nab bloomery

Colour generated magnetometry plot of Cinder Nab bloomery

Magnetometry plot of Cinder Nab bloomery

Magnetometry plot of Cinder Nab bloomery

Challenging conditions for the magnetometry survey on the bloomery at Ghyll Head, Windermere

Challenging conditions for the magnetometry survey on the bloomery at Ghyll Head, Windermere

The magnetometry survey at the Ghyll Head bloomery (north to top) was tightly constrained by the steep surrounding topography and dense vegetation cover. The interpretation of the site has come into question because of the features surrounding (and possibly masking) the bloomery mound as probably being associated with a later bobbin mill. Also Post-medieval period pottery and coal nodules were retrieved from the top surface of the slag mound.

Thankfully the geophysical survey results identified a single furnace located just below the main slag heap. The dipolar anomaly results for the furnace is depicted on the colour plot as a red blob almost completely surrounded by blue. This signal corresponds to a  small circular earthwork mound visible on the ground below the main slag mound. The rest of the results on the plot are related to the main slag mound. Interestingly there are no obvious results for features associated with the nearest building platform to the bloomery.

Colour generated magnetometry plot of Ghyll Head bloomery

Colour generated magnetometry plot of Ghyll Head bloomery

The site at Ghyll Head still needs many questions answering regarding the relationship between the bloomery and surrounding features. Was the bloomery a simple medieval period version powered by hand bellows? Was it a later water powered site with waterwheel and buildings? or are the surrounding buildings associated with the bobbin mill?

Magnetometry plot of Ghyll Head bloomery

Magnetometry plot of Ghyll Head bloomery

So what is next for these three bloomery sites? Well we will use the geophysical results and revisit each of them to retrieve secure dating samples to be processed for radiocarbon dating. I will also post the completed survey drawings for each of the bloomery sites as and when they are drawn up and overlay the geophyics results so they will all make a bit more sense to people who haven’t visited them in person. A special thanks should go to everyone who has helped both myself and Ian with the topographic and geophyical surveys over the last two weeks.

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6 thoughts on “Initial geophysics results from three of the bloomery sites investigated around Windermere

    • Those three surveys were done I think at 50cm intervals, but the survey at Blelham Tarn where we are excavating was done at 25cm as we needed it very detailed. The survey at Ghyll Head was challenging as the slope was very steep, we could only do half a 20m grid there, yet still found the furnace 🙂

      Reply
      • Thank you for taking the time to reply! Much appreciated. I can imagine the stagger in the data from the slope would have been a difficulty – let alone rough plants cropping up. The data looks very well presented – thank you again for the additional information and sharing the results.

  1. Sample resolution was 0.5 m along transects 0.5 m apart for three of the sites and 0.25 m along transects 0.25 m apart for the Blelham Tarn Site. The level of accuracy required to look for dipolar anomalies requires the use of a hand trigger and parallel sampling.

    Reply

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