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GEOarchaeology and PRehistory of Atlantic Societies(GEOPRAS)

Programme supported by ANR (n°CE27-024)

The GEOPRAS consortium comprises seven partners that have been involved for several years in coastal archaeology (UMR 6566 CReAAH, UMR 6554 LETG, UMR 5607 AUSONIUS, UMR 6553 ECOBIO, UMR 6539 LEMAR, UMR 7266 LIENSs, INRAP). It was born directly from the dynamics established in the framework of the IRN PrehCOAST, applying the reflections to Atlantic France.

Our programme studies the coastal societies of recent Prehistory (Mesolithic and Neolithic) on the French Atlantic shores in order to understand their social and economic organization and the role they play in broader historical dynamics such as neolithization. Characteristics such as the accumulation of goods through storage, specialised modes of production, and the emergence of a social hierarchy or a sedentary lifestyle are often attributed to these coastal populations, on the basis of ethnographic documents from the last two centuries. However, each of these social manifestations must be described according to regional environmental variables, without evolutionary preconceptions. Our research hypothesis is that environmental dynamics have greatly facilitated certain forms of historical evolution. This encourages us to determine with greater precision the nature of these environmental transformations, then to analyse human networks at the continent-ocean interface.

Corpus of archaeological sites integrated into the GEOPRAS programme

The first task will be to restore the environmental benchmarks. During the Mesolithic and Neolithic periods, most coastal landscapes were radically transformed by the sea-level rise and the associated processes of erosion and sedimentation. The coastal environments of the past will be reproduced through a three-level approach combining a large scale (region) with an intermediate scale (nearby landscape) and a local scale (archaeological site). Our consortium proposes a combination of methods suited to different geographical conditions (dunes, rocky coasts, marshlands) around the Bay of Biscay, testing the limits of several of them. To gain the best possible understanding of an “archaeological signal”, the GEOPRAS project will focus on developing rapid intervention and rescue methods for archaeology and geoarchaeology. We intend to apply these methods to sites currently being excavated or whose exploration is planned as part of the project, such as foreshore and marshland sites and shell middens. Optimal integrated methods and procedures will be developed for the recording of archaeological remains, which are often ephemeral on foreshores, as well as for sampling, particularly in shell middens. These procedures include geophysical surveys, archaeozoology, micromorphology, geochemistry, taphonomy, metagenomic approaches, and OSL datings.

Mesolithic Shell Midden of Beg-er-Vil (Quiberon, Morbihan, France)

The second task is to study how human societies have managed the land-sea interface. Shell middens have become the emblematic nodes of these coastal Holocene settlements because they contain an abundance of bio-archaeological data. They will be analysed to judge biodiversity as well as food practices.

Sampling and coring in Hoedic (Mesolithic Shell Midden, 2021).

The third task is to understand the specific features of technical systems in a maritime context, especially seafaring. This technical field is at the heart of all the questions raised about the relationships between coastal areas, as well as the decisive features of the various technical systems developed in these areas. To overcome the lack of knowledge of prehistoric watercraft, we suggest an approach, based on three disciplinary poles in permanent interaction: 1) ethnographic and historical references, 2) technological and use-wear analyses of lithic and bone tools, 3) experimentation.

In addition to proposing methodological developments, we aim to lay down the conceptual, methodological and technical foundations of a maritime prehistory with procedures adapted to coastal heritage. The results will be included in a handbook of maritime prehistory, to be published in French and English. The involvement of amateur archaeologists, observers, tourists and other citizens in scientific tasks will be anticipated and coordinated by inviting them to take part in the main scientific meetings and, of course, in field operations such as surveys, excavations and experiments.

About micromorphology….

The mission objective was to bring together the researchers working on aspects of site formation processes of coastal Mesolithic sites in Brittany, including existing samples from Hoedic (Morbihan), collected in the excavation seasons of 2019 at the archaeological site of Port-Neuf.

Hoedic 2021: micromorphological sampling in a Mesolithic layer by P. Arias (photo: G. Marchand).

For that, Dr. Carlos Simões stayed at the IUEM Brest, from Monday 21st to Friday 25th of November 2022, hosted by Dr. Marylise Onfray. Both micromorphology specialists, during the first two days, they carried out microscopic analysis of the existing micromorphological thin sections from Hoedic, producing the first descriptions as a basis for future analysis to conduct in coordination with the further members of the team working at the site.

In a one-day meeting, on the Wednesday 23rd, member of the GEOPRAS/PreCOAST specialists met at the IUEM to bring together data from several aspects of coastal geoarchaeological, geomorphological and geophysiscal research in Brittany, included that of Hoedic.

Shell Midden of Beg-an-Dorchenn: contemplation…

On Thursday 24th, a field trip was organised to the site of Beg-an-Dorchenn, in Pointe de la Torche (Finistère), where the remains of a Mesolithic shell midden is preserved, and aspects of coastal geomorphological dynamics and evolution could be observed.

On Friday 25th, a seminar was organized at the IUEM, with an introduction by Dr. Onfray, followed by a presentation of Dr. Simões titled “What is a shell midden? Microstratigraphic insights from Mesolithic sites in Iberia”, which closed the mission activities.