Nothing more now until Wednesday, 15th October when we have Helen Bradley on Adopt-a Monument.
Archaeomagnetic Dating at Castlehill, Penicuik
After being referred to us by David Connolly, Sarah-Jane Clelland, a PhD student at the University of Bradford, agreed to visit our site at Penicuik and to take samples of hearth areas for possible dating as part of her project. Sarah-Jane visited the site on Tuesday, 13th May and was able to sample two areas in trenches 1 and 2. The sampling consisted of inserting a series of small plastic capsules aligned to present-day magnetic north into the subsoil under the paving of the hearths. The samples hopefully have retained the direction of magnetic north after their last firing and can be checked with a magnetometer and assigned a date calculated from that alignment. This is possible as magnetic north moves by 0.2 of a degree per year, subject to some irregularities such as the Roman Iron Age where a deviation in magnetic north is referred to as the “Roman Hairpin”. Archaeomagnetic dating can go as far back as the late Bronze Age – about 1000 BC – so the estimated late Iron Age date assigned to the site by stone tool typology should fit in. It is not certain if the dating will work as the preferred substrata is clay rather than sand, but we should have results one way or the other in about two weeks.
Many thanks to Sarah-Jane for her assistance and we wish her well in her PhD project.
The final session at the castle/nunnery site took place on 3rd April when four 20 by 20m squares were ground resistance surveyed at the extreme southern side of the site. (Those taking part in the survey left at the end of the day feeling totally convinced that all the survey would show would be geology – now read on! Ed.)
Our first survey on this site took place on 23rd September 2006, and, in all, we have surveyed 10,800 sq. m. since then. It seems a long time since we started but we have also surveyed the Cousland pottery site and the two sites at Ogilface, near Armadale in the same period.
The surveys adjacent to the castle showed very few features, probably due to ground levels being changed by the excavation of limestone for burning in a kiln close by.
The survey of the final eight squares that lie in the field to the south of the castle field (completed on 3rd April) shows a large number of very clear, high resistance lines running approximately N-S and E-W that, by their alignment, suggest we might have found ecclesiastical buildings – it would be great if they turned out to be the nunnery which has been lost for a long time. A draft copy of our report on the survey is currently with David Connolly (who may have to organise a dig to determine what we have found).
Alongside the road to the south of Cousland lies Windmill Plantation. The O.S. name book from 1852 records that cist burials had previously been found on the site. In 1957 a farmer inserting fence posts also came upon burials some of which were excavated by Audrey Henshall and recorded in D.E.S. for that year. David is looking at the possibility of investigating this site further.
The pottery site field is sown with cereal which will not be harvested until Autumn so the completion of the ground resistance survey (and possible dig) will have to wait. Our thanks are due to David and the Cousland History Project for grant aid to cover our expenses on these sites.
Our dig at Castle Hill is now closed down for the season.