Soil can tell us a lot about the past and last week our volunteers learnt just how by Dr Fiona Grant. Pollen, charcoal, seeds and insects, to name but a few, can be preserved within the layers of earth and by extracting and studying these we can learn about past environments as well as human impact on their surroundings and even what they were growing and eating. However in order for us to be able to find any possible seeds, etc we had to turn our bucket of soil into mud! After adding water and mixing it we then had to slowly pour the water off through a sieve to catch any tiny seeds and charcoal that may be present. After collecting this we then had to search under the microscope to see if we had found anything and the exciting news is we found two seeds. Although we don’t know what these seeds were we could see that they had been burnt. All this training will help us if we are able to carry out excavations in the future as we all know now how important it is to carry out soil sampling.
Community archaeology project
Even after 700 years Chirk Castle and its landscape still hold many mysteries. Over the last few years the National Trust have been carrying out research to try to understand the castle and its surroundings in more detail. During 2015/16 an archaeological intern was placed at Chirk Castle to look at the landscape. They found old trackways possibly used to bring materials to build the castle as well as field systems which may pre-date the castle itself. Early in 2017 an archaeological survey of the castle was carried out too.
These surveys have hinted at a landscape and castle that still have lots to tell us. As a result a short pilot project has been set up to try to understand some of these mysteries. Volunteers will be working to carry out non-invasive archaeological techniques such as geophysics, which can pick up features such as walls buried underground.
Areas that will be surveyed are part of Offa’s Dyke, a large bank and ditch that is believed to have been built by Offa, King of Mercia in the 8th century, as a defence against Welsh attacks, as well as areas immediately outside the entrance to the castle to see if we can see any lost walls of the courtyard that used to be here.
Come back over the next few weeks to see what we have been up too and what we have found.
21 Jun 17
17 Jun 17
Hidden archaeology revealed at Chirk Castle
Last week the community archaeology project at Chirk Castle was busy carrying out a geophysical survey of the area outside the castle entrance. Geophysics is a non-invasive survey method used by archaeologists to see what is underground without damaging any of the archaeology. An intrepid group of volunteers braved the wet weather and spent the week surveying outside the castle and the initial results are interesting. It appears that there is a rectangular feature at right angles to the Distil Tower and a couple of circular features. What these features are is uncertain, hopefully excavation would answer these questions but could the rectangular feature be a building? Could it be something to do with the construction of the castle? Could the circular features hint at a much older prehistoric past? Sadly geophysics can’t give us the answer to these questions but what it does show us is that Chirk Castle still has lots of secrets to reveal.
01 Jun 17
Mapping in the 21st Century
This week volunteers got to learn about mapping in the 21st Century by Jon Dollery the GIS officer at the Royal Commission on the Ancient and Historic Monuments of Wales. Instead of having to get a series of maps out to look at features today there are plenty of online systems that allow us to do that in a more clutter free way. Volunteers learnt how to use free online software and export in various maps, such as the 50k and 25k OS series. After this was completed we moved on to learning all about georeferencing. Georeferencing is when you overlay an old historic map onto a modern map. This allows you to locate features in today’s landscape that may appear on old maps, such as buildings. Finally we learnt how to bring in data sets such as LiDAR, which we spoke about in last week’s blog. Here we can use the online software to look at the images and manipulate things like which direction the sun comes from to show up features that may not be visible when the sun is shining in a particular direction. Over the coming months the volunteers will be using this training to look at historic maps of the castle and the parkland as well as aerial photographs and putting them into the computer to see where features are in the modern landscape before going out to look at them on the ground to record them.