Microfossil provenance of British Iron Age lowland ceramic artefacts

Ceramics were central to many aspects of later prehistoric life and the pottery and the clays from which they were made had a powerful practical and metaphorical role in many societies. Over the last 30 years it has become standard archaeological practice to define ceramic fabrics in terms of their characteristic macroscopic inclusions and to suggest sources of the raw materials used. Characterisation and sourcing studies have, however, largely been restricted to clays and inclusions with distinctive rock types such as serpentinite from the Lizard peninsula. Much of southern and eastern Britain by contrast, consists of sedimentary deposits with an absence of mineralogically discrete outcrops. Consequently, investigation of the organisation of ceramic production and exchange in much of prehistoric Britain is hampered. Whereas the mineralogical content of ceramics sourced from sedimentary rock successions may be indistinct, the microfossil signature of such rocks can provide a powerful indication of provenance. Here we use microfossils to investigate the source of raw materials used in clays and ceramics at the Iron Age settlement of Burrough Hill, one of the few hill-forts in the East Midlands. Previous excavations at the site demonstrate occupation from the Neolithic to the 4th century AD, with the most intensive period of occupation during the Iron Age when the hill was a major pre-urban centre for the population of the region.

Burrough Hill sat in a densely occupied Iron Age landscape of farms and settlements. Archaeological evidence from an ongoing five-year programme of work already attests to the wide ranging contacts of the community living here, but this work has so far been limited to comparatively rare, high value or exotic items such as quern stones. Excavations during 2010 and 2011 have identified a range of ceramics from 4th century BC to 1st century AD at the main entrance and from houses and occupation deposits inside the northern edge of the hill-fort. At Burrough Hill and across the East Midlands generally, however, the ceramic repertoire of Iron Age communities is dominated by a stylistically conservative, geographically widespread and chronologically long-lived tradition of ceramics known as 'Scored wares'. Whilst the macroscopic diversity of its fabrics has long been recognised, it has rarely been possible to characterise and provenance this material.

Mud daub from the round houses and clay used in the construction of the ramparts comprise other examples of Iron Age clay procurement in the hill-fort. Archaeological investigation has already identified several hundred storage pits within the hill-fort and a series of round houses to the lee of the ramparts as well as an extramural settlement immediately outside the ramparts to the east of the hill-fort. Excavations in 2011 and 2012 will sample each of these areas to get a cross section of material from the settlement.

Burrough Hill is situated in a landscape of Mesozoic sedimentary carbonate and clastic rocks over which are smeared tills of late Quaternary age. The micropalaeontology of the Mesozoic rocks of the East Midlands is well documented. Less well known is the microfossil signature of the tills, which contain Cretaceous microfossils recycled from the Chalk Group of Yorkshire and Lincolnshire mixed with more locally derived Jurassic microfossils. Pilot studies at Burrough Hill already identify a rich repository of ostracods and foraminifera in ceramics, and in clay materials used to the construct walls. In conjunction with a detailed evaluation of the microfossil and sedimentological signature of the solid and drift deposits of the immediate vicinity of the hill-fort, the site provides an excellent case study by which to assess the geological provenance of ceramic and clay materials in a sedimentary landscape, and our study thus has widespread potential for interrogating other archaeological sites in the British landscape.

As detailed in 'academic beneficiaries' this project is of immediate interest to artefact specialists and later prehistorians (Neolithic-Late Iron Age) working in both the east and southeast of Britain where the rock succession is characterised by sedimentary deposits with distinct microfossil signatures. Our detailed systematic collection, identification and curation of calcareous microfossils from these sedimentary deposits in eastern England is also important to those researching the biostratigraphy, biogeography, palaeoecology and taxonomy of the British rock succession. In addition, this project will benefit the public sector, business and schools as indicated following.

Public Sector beneficiaries: are the BGS; English Heritage; and museums, and local government curatorial officers. BGS will benefit from enhancement of its core fossil collections that underpin its biostratigraphy and mapping expertise. Our fossil collections will also build on Quaternary data at the BGS used for the analysis of glacial landscapes in eastern England. English Heritage will benefit from the opportunity to develop policy and best practice guidelines on the mineralogical and microfossil analysis of clays and ceramics and to provide guidance to local authority and contract archaeologists. Other potential beneficiaries include museum and local government curatorial officers responsible for setting archaeological project briefs and standards in artefact analysis and treatment. The research will inform good scientific and curatorial advice and practice especially in relation to developer funded archaeology.

Business beneficiaries: The knowledge gained from the project and developed in its associated workshops and guidelines will also benefit contract archaeological units in developing specialist skills and services in artefact analysis as well as provide information about the significance and cost of such work to developers who may commission it. Our workshops will also connect archaeologists with micropalaeontologists operating in commercial companies that provide biostratigraphic expertise.

Third sector and general public beneficiaries: Further beneficiaries are the wider non-professional archaeological community at both a local and national scale. At a local level the Burrough Hill Project works in partnership with the Leicestershire Community Archaeology Scheme and Leicestershire County Council to foster and develop public involvement in field archaeology, artefact analysis, and the wider appreciation of the historic landscape. Knowledge gained from the project will further encourage such participation and extend it to an understanding of the links between archaeology and the fossil record of the local landscape. At a national scale the results of the project will highlight the value of further science based analysis of archaeological ceramics, one of the most commonly recorded artefacts in community based field projects, and encourage a greater awareness of the links between archaeological materials and the geological fabric of the British landscape.

Schools and schoolchildren: Certain results from the project will be of interest to Schools at a local and regional scale. At a local scale the Earnest Cook Trust currently supports the Burrough Hill project in a programme of outreach aimed at Key Stage 1 and 2 pupils. This focuses on the Iron Age and the interpretation of archaeological evidence through a programme of artefact handling sessions, school visits and a schools education pack developed in conjunction with the Trust and local schools. A second potential group is Year 12 and 13 students from across the country that the University of Leicester engages annually in Archaeology Masterclasses designed to educate and enthuse 16-18yr olds about archaeology as a possible degree and/or career.