As the 2016 Festival of Archaeology enters its final few days, we have a couple of blogs from heritage scientists at Historic England. The first, from Dr Ruth Pelling, describes her work as an archaeobotanist to identify and interpret plant remains from Historic England excavation projects or funded projects. She talks about working with examples of charred grain from the Pitt-Rivers Archive and how this can increase our knowledge of early farming.
Heritage Science in Action …archaeobotany
Dr Ruth Pelling, Senior Archaeobotanist, Historic England
Archaeobotany is the study of plant remains from archaeological sites. Most commonly this involves the examination of charred grain, chaff, pulses, fruit and nut remains, tubers, rhizomes, weed seeds, and charcoal which have survived as a result of being burnt. Plants can also be preserved in anaerobic deposits where oxygen is excluded (most commonly due to water-logging) thus preventing bacterial and fungal action. Leaves and even flowers may survive in such conditions. A third type of preservation is mineral replacement, in which all or part of the structure of the plant is replaced by mineral salts, most commonly calcium phosphate, or mineral preserved remains where material is preserved due to its proximity to metal corrosion products. Identification is based on the physical characteristics of the item: the morphology (shape and form), surface cell structure, and internal cell structure.
My job as the senior archaeobotanist is to identify and interpret plant remains from Historic England excavation projects or funded projects. I also provide advice and support to other archaeobotanists, including those employed in the commercial sector. I identify research priorities in archaeobotany, either locally or nationally, and answer individual enquiries from helping with identification to developing sampling strategies. At the moment I am working on a really exciting project examining material held in the Pitt-Rivers archive at Salisbury Museum.
Augustus Henry Lane-Fox Pitt Rivers (14 April 1827 – 4 May 1900) was one of the leading anthropologists and archaeologists of the Victorian age. He conducted a number of excavations, particularly in the area of Cranborne Chase in Dorset, and was an avid collector of antiquities and ethnographic artefacts. In 1975 Salisbury and South Wiltshire Museum was gifted the Wessex collections by HM Treasury. Amongst the archive were a number of cigar and pill boxes full of charred grain, complete with the original labels and identifications. It is a great honour to be able to look at this material and re-identify the cereal remains with a more scientific eye.
Pitt-Rivers did not employ modern sampling and flotation methods as practiced today, so his plant samples are derived from grain caches which were substantial enough to be spotted during excavation. As such the material represents unusual burning events of stored grainor grain accidentally burnt during processing events, as opposed to the everyday processing losses we usually encounter. A complete catalogue of the samples, possibly coupled with radiocarbon dating, will enhance our knowledge of Iron Age and Roman farming in the Dorset region and highlights the value of archived material, particularly when contextual information is as thorough as that provided by Pitt-Rivers.
Amongst the samples in the collection are two boxes of grain from the Swiss Lake settlements labelled ‘burnt wheat from the Swiss Lakes, Brice Wright’s Sale’. The Swiss Neolithic lake dwellings were first discovered in the mid-19th century when wooden house posts were exposed in Lake Zurich during the winter of 1853-4 due to exceptionally low water levels. Finds from the sites were sold to visitors from all over the world in the late 19th century. This included samples of plant remains. It is likely that the Pitt-Rivers samples derive from Robenhausen, where archaeological layers dated from the Neolithic (4th and 3rd millennium BC) to the Late Bronze Age. Interpretation is limited as there is little by way of contextual information but the material shows how amazing preservation of this ancient plant material can be. Burning grain deposits were presumably fairly rapidly extinguished when the house platforms fell into the water, where they lay in stable waterlogged conditions within the lake silts until discovered thousands of years later. Similarly remarkable preservation has been uncovered at the site of Must Farm in Cambridgeshire which is currently being studied in Cambridge.