SEArch what and where?
In the Atlantic regions of Iberia, from the co-existence of coastal-dependent foragers and possibly seaborne farmers to the appearance, generations later, of some of the most impressive expressions of megalithic monuments, the story of these revolutions remains untold. About 7500 years ago, the first farmers settled farmland on coastal regions in SW Iberia that were lesser populated by Mesolithic foragers [1], while, through terrestrial routes, they arrived hal2f a millennium later to the Northern coast [2, 3]. The reason for these differential dynamics in farming spread is debated [4, 5], but, as a “world’s end”, Atlantic Iberia staged some of the most impactful cultural interactions of Prehistory.
Have a look below to case-studies where SEArch addresses these topics, and learn more about them soon!
Algarve
In western Algarve there are several shell middens, dated to diferent periods of human history. These sites are located in sand dunes on top of limestone sea cliffs and in the bottom of strem valleys incising metamorphic rocks, such as the one at Castelejo valley in the left image. The sites of Castelejo and Rocha das Gaivotas preserve continuous shell midden layers of Mesolithic and Neolithic occupations with combustion structures [6]. Thus, this region has a lot of potential to search for answers to our research questions.
Lower Sado Valley
Twelve known shell midden sites are located in the aeolian sand covers of Plesitocene and Holocene age on top of the gentle hills bordering both margins of the Sado valley, today converted in extensive rice fields. These sites are 8000 years old and comprise several human burials, most underneath the shelly layers. Some of the sites, like Cabeço do Pez in this image, yield Neolithic pottery within upper shell midden layers [7]. Recent field research at the project SADO MESO allowed microstratigraphical reconstruction of the formation of these sites, and will bu used to continue investigating shellfish processing and the sites’ functions.
Barrosinha
In the late Neolithic and Chalcolithic (c. 4000-3000 years ago), rising sea-level and fluvial inputs caused the progressive migration of estuarine conditions downstream from the lower Sado valley toward the current estuary. Coastal populations settled in the sand spits of the Comporta region overlooking the wetlands, and formed shell middens [8], such as Barrosinha, in the framework of an established farming economy, where coastal resources were vital, and a new economic activity seems to have been frequent: salt production.
Muge
Eight thousand years ago, the lower Tagus valley was an extensive tidal environment with abundant coastal resources that atracted human populations to live semi-sedentarily in its banks, constructing shell mounds as they acumulated and moved shelly sediments arround to flatten out new living surfaces. In site such as Cabeço da Amoreira and Cabeço da Arruda, more than a hundred of burials have been found below and within the shelly deposits. The superposition of several ocupation and renewall events originated a complex stratigraphy enclosing microscopic traces of human behaviour. ICArEHB undertakes permanent research in the Muge shell middens project.
Asturian: El Alloru and El Mazo
The coastal region of eastern Asturias and western Cantabria is a littoral kartsic platform, plenty of limestone caves and rockshelters. These settings were used by the hunter-gatherers between 8000 and 5000 years ago as temporary – maybe seasonal – camps, through successive occupations and accumulation of shell middens resulting from processing resourced from the rocky intertidal ecosystsems. Few exceptions, such as El Mazo, preserve stratified deposits of the occucpations [9]. This is because, today, most of the record of these shell midden deposits are preserved as carbonate-cemented, hanging remnants from the caves’ walls. This is the case (among many others) of El Alloru, where ocupation remains without shell middens in the vecinity of the rockshelter was also revealed [10]. The shell middens’ formation plays a key-role in answering open questions about settlements patterns of these Mesolithic populations.
Cantabria: La Fragua and La Chora
In the coast of eastern Cantabria, extensive marshlands develloped in previous low fluvial environments during the Mesolithic and, being a karstic mountanous region, also many caves suitable for temporary camps were available. The changing environmantal conditions and resources during the early Holocene climatic events, and the adaptabions of coastal populations are well preserved in shell midden sequences such as La Fragua and La Chora, both in the Asón river estuarine system, seen in the photo beteween the Mount Buciero in the background and the inland mountains. Shell middens are also excellent archives of plaeoenvironmental information to characterise this landscape in the early Holocene. Seasonal data from stable isotpode analysis, suach as perfomred by the Palaeoshells project (IIIPC – University of Cantabria), will be combined with microstratigraphic data from the SEArch project.
References:
1. Isern N, Fort J, Vander Linden M (2012) Space competition and time delays in human range expansions. Application to the neolithic transition. PLoS One 7: e51106.
2. Bernabeu Aubán J, Barton CM, Pardo Gordó S, Bergin SM (2015) Modeling initial Neolithic dispersal. The first agricultural groups in West Mediterranean. Ecological Modelling 307: 22-31.
3. Zilhao J (2000) From the Mesolithic to the Neolithic in the Iberian Peninsula. In: Price TD, editor. Europe’s first farmers. pp. 144-182.
4. Drake BL, Blanco-González A, Lillios KT (2017) Regional Demographic Dynamics in the Neolithic Transition in Iberia: Results from Summed Calibrated Date Analysis. Journal of Archaeological Method and Theory 24: 796-812.
5. Carvalho AF (2018) When the Mediterranean met the Atlantic. A socio-economic view on Early Neolithic communities in central-southern Portugal. Quaternary International 470: 472-484.
6. VALENTE, M. J., DEAN, R. M. & CARVALHO, A. F. 2014. Shell middens in Western Algarve (Southern Portugal) during the Mesolithic and Early Neolithic: functionality, subsistence and material culture. In: ROKSANDIC, M., MENDONÇA, S., EGGERS, S., BURCHELL, M. & KLÖKLER, D. (eds.) Cultural Dynamics of Shell-Matrix Sites. Gainesville: University Press of Florida.
7. DINIZ, M. T. & ARIAS, P. 2012. O povoamento humano do paleo-estuário do Sado (Portugal): problemáticas em torno da ocupação dos concheiros mesolíticos. In: ALMEIDA, A. C., BETTENCOURT, A. M. S., MOURA, D., MONTEIRO-RODRIGUES, S. & ALVES, M. I. C. (eds.) Environmental changes and human interaction along the Western Atlantic edge / Mundanças ambientais e interação humana na fachada atlântica ocidental. Coimbra: APEQ-CITCEM-CEGOT-CGUP-CCT.
8. SOARES, J. & SILVA, C. T. 2013. Economia agro-marítima na Pré-história do estuário do Sado Novos dados sobre o Neolítico da Comporta. Setúbal Arqueológica-Pré-história das Zonas Húmidas. Paisagens de Sal, 14, 145-170.
9. GUTIÉRREZ-ZUGASTI, I., TONG, E., GARCÍA-ESCÁRZAGA, A., CUENCA-SOLANA, D., BAILEY, G. N. & GONZÁLEZ-MORALES, M. R. 2016. Collection and consumption of echinoderms and crustaceans at the Mesolithic shell midden site of El Mazo (northern Iberia): Opportunistic behaviour or social strategy? Quaternary International, 407, 118-130.
10. ARIAS, P., CUBAS, M., FANO, M. A., PARDO, J. F. J., SALZMANN, C., TEICHNER, F. & TEIRA, L. C. 2015. Where are the ‘Asturian’dwellings? An integrated survey programme on the Mesolithic of northern Spain. Antiquity, 89, 783-799.
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