July 2008
Society Activities
Lectures
Nothing more now until Wednesday, 15th October when we have Helen Bradley on Adopt-a Monument.
Archaeomagnetic Dating at Castlehill, Penicuik
We have received the report on the Archaeomagnetic Dating at Castlehill. Sadly it was unsuccessful – rather than reproduce the full report I have just copied the summary –
“A total of 25 samples were collected and all the samples had a measurable remanence but the magnetisation was weak. These results indicate that most of the material sampled does not contain sufficient magnetic minerals to record a consistent and stable magnetic direction or was not heated to an adequate temperature and therefore are unable to produce a reliable archaeomagnetic date. It was not possible to produce an archaeomagnetic date for either the feature from trench 2 or for trench 1. The archaeomagnetic evidence is not able to determine if the activity in either trench relates to any proposed Iron Age occupation in the vicinity.”
Excavation on the Dalmeny Estate
Two years ago we were joined by members of the University of Edinburgh Archaeology Dept. to dig a series of test pits in the field on the W side of the River Almond in the area where we had found the largest number of lithics in our 1997-9 field walking. The lithics were confirmed as Mesolithic by Dr Catriona Pickard who supervised the dig and who, on the last day of excavation in August 2006, recovered carbonised hazelnut shells from the final pit excavated. The hope has always been that this site would be of similar date to that excavated in Cramond in our Trench F-G which holds the record for the oldest dated site in Scotland at 10K years B.P.
The Factor of Dalmeny Estate has given outline permission that, once the present crop is off the field, a larger examination of the area from which the hazelnut shells were recovered can take place. By September the shells will have been carbon dated. We will let you know once the date of access to the field is confirmed. The dig will again be supervised by Catriona.
Penicuik
Our dig at Castle Hill is now closed down for the season.
Acrehead
The site of this farm (recorded on the Bavelaw Estate in 1776 but not since) has been surveyed as part of the Scottish Rural Past project. To see whether we can add further information on the farm we will make a ground resistance survey on 9th August. The area is only about 800sq.m. so the proposal is to do it twice using 0.5 and 1.0m mobile probe spacing to see whether a deeper ‘look’ gives any difference in building outline.
Magnetometry Survey to the East of Cramond House
The field to the E of Cramond House was relayed out in 20 by 20m squares on 19th May in preparation for the survey conducted by Dr Peter Morris on 20th May. All went well and there was no need to protect equipment from the rain. Peter, in his usual efficient manner, emailed a variety of different printouts of the results that evening. Some very significant magnetic anomalies showed up but before any conclusions could be made we had to return to survey in the more recently planted trees that were within cattle proof fencing. The wire that holds the fencing together has a large magnetic signature that has to be discounted. There are, thankfully, many more magnetic anomalies than there are fenced trees.
The probable Roman bank/wall and ditch, that was identified in the ground resistance and linear array surveys, shows up well in the magnetic survey on the edge of the old raised beach. The line curves to the S at the E end and heads NW at the W end, in both cases following the line of the raised beach shown in the Drift Geology map. This is also the line of the walkway shown in the Bauchop map of 1815 and appears to continue the line of the Roman ditch found by Nick Holmes beside the Tower.
A number of magnetic anomalies appear beside the ‘wall’ in the extreme NE corner just where Roman ovens could have been built. There are many lines parallel to the tree avenue which may indicate garden features but, as the raised beach is also on this bearing, they could equally well be Roman features parallel to the wall. Once the best interpretation has been made the project will be written up as requested by Historic Scotland when giving their permission to survey over the Scheduled Area.
Ogilface Castle, Armadale
The geophysical survey, made last year in conjunction with Dr John Wells and with magnetometry conducted by Dr Peter Morris, was written up as EAFS Geophysical Paper No 19. It covered the area ground resistance and the magnetometry but could throw no light on where the descending steps from the castle led. These steps were partially excavated by a team from Armadale Academy some 20 years ago. Peter now has a resistive linear array kit to make surveys that, with probes at 1.0m spacing, can ‘look’ to a depth of about 2.5m. It is possible to ‘look’ more deeply with wider probe spacing but this results in a loss of detail.
John has arranged permission from the farmer and we will work with Peter on 5th August to survey for a possible cellar or dungeon. Even if it is completely infilled the walls should appear as high resistance. Linear array measurements have given good indications of Roman ditches at Cramond but to ‘look’ for a dungeon is a new challenge. Should the weather on the 5th be dreadful, the survey will be on the 7th.