Chronology of the Burial Activity of the Last Hunter-Gatherers in the Southwestern Iberian Peninsula, Portugal

Abstract

For most of human history, funerary burial has been unusual. Archaeology shows a shift in funerary practices in postglacial hunter-gatherers, in parts of Europe during the Late Mesolithic. This is documented by the burial grounds in the Tagus and Sado valleys in the southwestern Iberian Peninsula, Portugal, where ca. 376 burials were excavated. This study presents a chronology for the burial activity in these sites and contextualizes the start and end activity phases within regional environmental changes and cultural developments. The dataset consists of 76 14C dates on human bone (19 new, 57 published) including new dates from contexts in Portugal outside these valleys. Bayesian chronological models were defined in OxCal, and protein carbon contributions of marine foods were estimated by the Bayesian mixing model FRUITS. The results indicate a broader timeframe for the Late Mesolithic in Portugal, than previously suggested, starting during a period of significant environmental changes, ca. 8500–8300 cal BP, and ending ca. 7000 cal BP. The burial activity decreased during the establishment of Neolithic farmers in southwestern Iberia from ca. 7450 cal BP, however, these burial grounds continued to be used by Mesolithic hunter-gatherers, showing that diverse social structures and worldviews coexisted for several generations.

Environmental Changes and Cultural Transitions in SW Iberia during the Early-Mid Holocene

“…9-7.5 ka BP, recent palaeodemographic studies propose a steady growth in population reflected in a concentration of archaeological sites in Central-South Portugal (Muge and Sado estuaries) and across the Algarve, although here in a more dispersed pattern [114]. Most of the sites concentrated in Western Algarve are shellmiddens and with exemption of Vale Boi, where a human tooth dating of Mesolithic but without a funerary context was described [16], all the occupations in this region are seasonal camps focused on the collection of local resources, mainly marine food but also flint material [13]. Some hypotheses correlate these sites with the existence of some (semi)permanent basecamps on which they would depend and that would have similar characteristics to those from the Sado and Tejo estuaries, with elaborated habitational structures, human burials, and broad-spectrum subsistence strategies [6,12,115,116].…”

“…In the Cape São Vicente region, shell-middens (Alcalar 7, Ribeira de Alcantarilha) and temporary open-air sites (Vale Santo I, Padrão) based on the seasonal exploitation of marine and lithic resources are still present [12]. Moreover, some Mesolithic sites revealed later Neolithic layers (Castelejo, Barranco das Quebradas, Rocha das Gaivotas, Vale Boi) [12,13,16]. Two necropolis caves (Ibn-Ahmmar, Algarão da Goldra) were also assigned to this period.…”

Mummification in the Mesolithic: New Approaches to Old Photo Documentation Reveal Previously Unknown Mortuary Practices in the Sado Valley, Portugal

“…The first and largest excavations in the Sado middens were carried out by the National Museum of Archaeology, Lisbon, between 1958 and1964, recovering more than 100 skeletons dating to between 8150 and 7000 cal BP (Peyroteo-Stjerna, 2021).…”

“…Despite multiple attempts, only two skeletons from Arapouco (1962, 2A) and S. Bento (2013, XIV) have provided reliable radiocarbon measurements, ranging between 8150 and 7900 cal BP (Cunha & Umbelino, 2001;López-Dóriga et al, 2016;Peyroteo-Stjerna, 2016, 2021, indicating that burial activity at the two sites was broadly contemporaneous.…”

The role of climate, marine influence and sedimentation rates in late-Holocene estuarine evolution (SW Portugal)

“…BP; e.g. Peyroteo-Stjerna, 2016) lived and exploited the Sado estuary surroundings (Figure 1).…”