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Olivers Mount, Shrawley, Worcestershire PDF Print E-mail

Archaeological surveys and excavations

To view the day to day record of the excavation visit http://www.gilraenarchaeology.blog.co.uk

Archaeological Investigations Ltd have been working in conjunction with Shrawley and District History Society, AOC Archaeology and Worcester University Earth Science to investigate this rather remote ancient monument.

Area of building  One area of the site containing a building that might be targeted for excavation.

The project involves local comminity input and is funded by the Local Heritage Initiative through the the Lottery.   

Work on site has embraced a multitude of methods and techniques, both old and new:
1 - further historical research by the local society
2 - a consideration of local geology by Worcester University Earth Science Group.

Quarry face

3 - major topographic survey (AIL)
4 - resistivity survey (AIL)
5 - gradiometer survey (AIL)
6 - radar survey (AIL)
7 - excavation (AOC)
There are also a number of community events/education days for local schools and training days for local interested volunteers arranged by AIL.

   Potted history

Shrawley Castle was built around the year 1100. After the Norman Conquest and the Domesday Book , Shrawley was acquired through marriage by the Beauchamps of Elmley Castle, from the heiress of Urso de Abetot, Sheriff of Worcester. For about the next 300 years, lieutenants to the Beauchamps, the Le Poers, occupied the castle. They were lords of the manor of Shrawley until the last of their line, Aline le Poher, fell out with the Church and was excommunicated in the mid 1300s. The manor passed back to the Beauchamps who dismantled the castle in favour of their other castle, Holt Castle, 2 miles downstream. The Shrawley Castle then became a quarry site of quality building stone by locals till the English Civil War when the Royalists used what was left as a gun emplacement.


Survey

Initial stages

The project is indebted to the Forestry Commission who have assisted in clearing the site to enable the surveys to take place. At the initial planning stage it became apparent that there was much more than just the top of the hill that might be of interest. Following the initial survey of the main earthworks a further more extensive survey has been undertaken to put the site in its context.
 Planning the project
 Earthwork plot of the site

Survey results  

The survey has revealed the positions of trenches excavated across the site by Mr & Mrs S.W. Masterman in 1928-30. They published their results in the Worcester Archaeological Society Transactions, Vol VII, 1930.  This does not quite match the surveyed information and it will be interesting to compare it with the geophysics results.


 Resistivity survey

The method

Resistivity survey works on the basis that different buried materials will affect the way in which electricity flows through the ground. It is most commonly used to identify buried walls or masonry in archaeology.

The plot to the right shows the results of such a survey across the top of the motte at Oliver's Mount. In the plot red readings represent areas of high resistance that might be expected to be caused by buried walls. Blue is low resistance and could be caused by thick soil deposits or areas that were devoid of stone structures.

 

 Resistivity plot
Resistivity interpretation 

Interpretation

The data is looked at at various levels to establish a more precise outline for each of the areas demonstrating either high or low resistance anomalies. The plot to the left is one possible interpretation of the location of structures that might be causing the responses. Note that the curtain wall is part way down the slope in this model and there seem to be a number of buildiNgs distributed around the outer edge of the top of the motte.


  Gradiometer Survey

 Gradiometer plot

Gradiometer survey is a means of mapping the earth's magnetic field. It relies on a ready supply of iron in the soil. When in the past man has heated the ground through fies or ovens or kilns, then this enhances the magnetic properties of the soil. Soil filling features such as ditches or within voids left by rooms can also be more magnetic than the surrounding ground. These slight differences in magnetic properties can be measured and mapped to produce a plot like the one on the left. Here the red readings are positive and the blue negative magntetism. The deeper the colour the stronger the response.

The plot to the right shows a number of responses identified as being of potential interest. For example the response at "A" might be due to an old fire place or hearth or a bread oven. The yellow spots identify features that could be small pits or large post holes. The purple areas indicate possible features filled with more magnetic soil.

 Gradiometer interpretaion

                              Ground Penetrating Radar survey                

 Radar plot

Ground penetrating radar works  by transmitting a high frequency signal into the ground and measuring the time and intensity with which it returns. It is possible to identify buried stone walls using this method.

To collect the data the radar is mounted on a cart along with  a logger that lets the operator monitor the data as it is collected. In the case to the right data is being collected across an area that had previously been excavated and revealed a stone building or base of a tower. Survey in progress 
 Radar interpretation

The advantage with using radar is that the data can be sliced horizontally until a depth is reached where features can be identified. It is much less clear cut in many circumstance than resistivity. In the plot to the left the yellow areas may be buried structures, and these match those identified by the resitivity well. The green area is noticably different and one possibility is that it was a ramped entrance into the castle that has since been filled in - notice how it aligns with a hollow on the earthwork plot.

 

                       Excavation

 May 13th meeting

Attended the meeting:

Rod Sproat - Shrawley and district Local History Society

Valerie Powick - Shrawley and district Local History Society

Phil Rudlin - Forestry Commission

John Bingham - English nature

Ed Symmonds - AOC Archaeology

Robert Gillespie

Andy Boucher - Archaeological investigations LTD

Joe Harrison - Website Update  

Members of the project team met with the forrestry commission and English Nature to finalize details of the excavation work.

It's planned to open up 24ms squared of trench at specific locations on the site. The two areas to be targeted are north of D and at K (view map)

These target a possible tower identified my Masterman (view map) together with one of his postulated towers.

View PDF

 May 13th

 

 
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