Hydroclimate variability from western Iberia (Portugal) during the Holocene: insights from a composite stalagmite isotope record

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Thatcher, D. L., Wanamaker, A. D., Denniston, R. F., Asmerom, Y., Polyak, V. J., Fullick, D., Ummenhofer, C. C., Gillikin, D. P., & Haws, J. A. Hydroclimate variability from western Iberia (Portugal) during the Holocene: insights from a composite stalagmite isotope record. Holocene, (2020): 095968362090864, doi:10.1177/0959683620908648.Iberia is predicted under future warming scenarios to be increasingly impacted by drought. While it is known that this region has experienced multiple intervals of enhanced aridity over the Holocene, additional hydroclimate-sensitive records from Iberia are necessary to place current and future drying into a broader perspective. Toward that end, we present a multi-proxy composite record from six well-dated and overlapping speleothems from Buraca Gloriosa (BG) cave, located in western Portugal. The coherence between the six stalagmites in this composite stalagmite record illustrates that climate (not in-cave processes) impacts speleothem isotopic values. This record provides the first high-resolution, precisely dated, terrestrial record of Holocene hydroclimate from west-central Iberia. The BG record reveals that aridity in western Portugal increased secularly from 9.0 ka BP to present, as evidenced by rising values of both carbon (δ13C) and oxygen (δ18O) stable isotope values. This trend tracks the decrease in Northern Hemisphere summer insolation and parallels Iberian margin sea surface temperatures (SST). The increased aridity over the Holocene is consistent with changes in Hadley Circulation and a southward migration of the Intertropical Convergence Zone (ITCZ). Centennial-scale shifts in hydroclimate are coincident with changes in total solar irradiance (TSI) after 4 ka BP. Several major drying events are evident, the most prominent of which was centered around 4.2 ka BP, a feature also noted in other Iberian climate records and coinciding with well-documented regional cultural shifts. Substantially, wetter conditions occurred from 0.8 ka BP to 0.15 ka BP, including much of the ‘Little Ice Age’. This was followed by increasing aridity toward present day. This composite stalagmite proxy record complements oceanic records from coastal Iberia, lacustrine records from inland Iberia, and speleothem records from both northern and southern Spain and depicts the spatial and temporal variability in hydroclimate in Iberia.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported, in part, by the US National Science Foundation (Grants: #1804528 to ADW; #1804635 to RD; #1804132 to CCU; #1806025 to YA and VP; #1805163 to DPG; BCS-0455145, BCS-0612923, and BCS-1118155 to JAH)

O Paleolítico Médio no território português

En este artículo se presenta un breve resumen sobre el estado del arte del Paleolítico Medio en Portugal enfocandose la industria lítica, el registro faunístico y los patrones de asentamiento. Aunque el número de depósitos no sea muy grande, parece claro que el territorio portugués ha sido donde los últimos neanderthales sobrevivieron. Al mismo tiempo, también parece claro que, al menos por lo menos ~ 240 mil años, estas comunidades tenían una serie de características únicas en su comportamiento que las distingue a los grupos situados más allá de los Pirineos. De hecho, mientras que estos eran expertos en la caza de renos con herramientas de sílex, los situados en el territorio portugués se especializan en la exploración ecléctica de los recursos disponibles. Esta diferencia puede estar relacionada con las diferencias sustanciales en el clima y el paisaje, ya que la zona en cuestión no muestra evidencia de fuerte impacto del endurecimiento de las fases de la glaciación. Esta explotación variada de recursos parece ser la base de la supervivencia tardía de los grupos neanderthales en el extremo occidental de Iberia

Paleoecologia e ocupação humana da Lapa do Picareiro: resultados preliminares

This paper presents the preliminary results of faunal, charcoal and lithic analyses resulting from excavations in Picareiro Cave. This archaeological work took place between 1994 and 2001. The project was funded by IPPAR, IPA, JNIC, National Geographic Society and Archaeological Association of Algarve. The process of cave filling started in OIS 4 and lasted until recent times, and there are Gravettian, Magdalenian, Epipaleolithic, Early Neolithic and Bronze age occupations. The paper will focus only on the Paleolithic and Epipaleolithic human occupations dating between c. 25 and 8 000 BP. This study, still preliminary, focus on aspects of local and regional paleoecology and paleoenvironment. Other relevant aspects presented in this study are data on the use of space inside the cave by the Paleolithic hunter-gatherers, as well as the use of new technologies of hunting, fishing and transportation, and its impact on the local and regional natural resources. Finally, these data allow the formulation of models on settlement system and land use patterns of Upper Paleolithic of Estremadura.Este trabalho apresenta os resultados da análise preliminar dos dados da fauna, antracologia e material lítico resultantes das escavações da Lapa do Picareiro. A escavação arqueológica do Picareiro teve o seu início em 1994 e terminou em 2001, tendo tido o apoio de várias instituições. A Lapa do Picareiro tem um preenchimento sedimentar que terá começado durante o OIS 4 e continuado até ao Holocénico, com ocupações do Gravettense, Magdalenense, Epipaleolítico, Neolítico Antigo e Idade do Bronze. O trabalho agora apresentado foca apenas as ocupações paleolíticas e epipaleolítica, com cronologias compreendidas entre os 25 000 e os 8000 BP. Este estudo, ainda que preliminar, debruça-se sobre aspectos de paleoecologia e do paleoambiente local e regional. Outros aspectos relevantes deste estudo são as questões da utilização do espaço dentro da gruta pelas comunidades humanas paleolíticas, bem como a utilização de tecnologias referentes à produção de utensilagem lítica, caça e pesca, e o consequente impacto na utilização dos recursos naturais locais e regionais. Finalmente, esses aspectos permitem a formulação de hipóteses no que concerne a padrões de sistemas de povoamento e utilização dos recursos naturais, e a integração da Lapa do Picareiro no contexto cultural do Paleolítico Superior da Estremadura

Paleoecologia e ocupação humana da Lapa do Picareiro: resultados preliminares

This paper presents the preliminary results of faunal, charcoal and lithic analyses resulting from excavations in Picareiro Cave. This archaeological work took place between 1994 and 2001. The project was funded by IPPAR, IPA, JNIC, National Geographic Society and Archaeological Association of Algarve. The process of cave filling started in OIS 4 and lasted until recent times, and there are Gravettian, Magdalenian, Epipaleolithic, Early Neolithic and Bronze age occupations. The paper will focus only on the Paleolithic and Epipaleolithic human occupations dating between c. 25 and 8 000 BP. This study, still preliminary, focus on aspects of local and regional paleoecology and paleoenvironment. Other relevant aspects presented in this study are data on the use of space inside the cave by the Paleolithic hunter-gatherers, as well as the use of new technologies of hunting, fishing and transportation, and its impact on the local and regional natural resources. Finally, these data allow the formulation of models on settlement system and land use patterns of Upper Paleolithic of Estremadura.Este trabalho apresenta os resultados da análise preliminar dos dados da fauna, antracologia e material lítico resultantes das escavações da Lapa do Picareiro. A escavação arqueológica do Picareiro teve o seu início em 1994 e terminou em 2001, tendo tido o apoio de várias instituições. A Lapa do Picareiro tem um preenchimento sedimentar que terá começado durante o OIS 4 e continuado até ao Holocénico, com ocupações do Gravettense, Magdalenense, Epipaleolítico, Neolítico Antigo e Idade do Bronze. O trabalho agora apresentado foca apenas as ocupações paleolíticas e epipaleolítica, com cronologias compreendidas entre os 25 000 e os 8000 BP. Este estudo, ainda que preliminar, debruça-se sobre aspectos de paleoecologia e do paleoambiente local e regional. Outros aspectos relevantes deste estudo são as questões da utilização do espaço dentro da gruta pelas comunidades humanas paleolíticas, bem como a utilização de tecnologias referentes à produção de utensilagem lítica, caça e pesca, e o consequente impacto na utilização dos recursos naturais locais e regionais. Finalmente, esses aspectos permitem a formulação de hipóteses no que concerne a padrões de sistemas de povoamento e utilização dos recursos naturais, e a integração da Lapa do Picareiro no contexto cultural do Paleolítico Superior da Estremadura

Late Pleistocene raised beaches of coastal Estremadura, central Portugal

We present new stratigraphic, sedimentological, and chronological data for a suite of tectonically raised beaches dating to Marine Isotope Stages 5, 4, and 3 along the Estremadura coast of west-central Portugal. The beach deposits are found in association with ancient tidal channels and coastal dunes, pollen bearing mud and peat, and Middle Paleolithic archaeological sites that confirm occupation of the coastal zone by Neanderthal populations. The significance of these deposits is discussed in terms of the archaeological record, the tectonic and geomorphic evolution of the coast, and correlation with reconstructions of global climate and eustatic sea-level change. Direct correlation between the Estremadura beach sections is complicated by the tectonic complexity of the area and the age of the beach deposits (which are near or beyond the limit of radiocarbon dating). Evidence from multiple sites dated by AMS radiocarbon and optical luminescence methods suggests broad synchroneity in relative sea-level changes along this coast during Marine Isotope Stage 3. Two beach complexes with luminescence and radiocarbon age control date to about 35 ka and 42 ka, recording a rise in relative sea level around the time of Heinrich Event 4 at 39 ka. Depending on assumptions about eustatic sea level at the time they were deposited, we estimate that these beaches have been uplifted at rates of 0.4-4.3 mm yr-1 by the combined effects of tectonic, halokinetic, and isostatic processes. Uplift rates of 1-2 mm yr-1 are likely if the beaches represent sea level stands at roughly 40 m below modern, as suggested by recent eustatic sea level reconstructions. Evidence from coastal bluffs and the interior of the study area indicates extensive colluvial, fluvial, and aeolian sedimentation beginning around 31 ka and continuing into the Holocene. These geomorphic adjustments are related to concomitant changes in climate and sea level, providing context that improves our understanding of Late Pleistocene landscape change and human occupation on the western Iberian margin. © 2009 Elsevier Ltd. All rights reserved

The early Aurignacian at Lapa do Picareiro really is that old: A comment on ‘The late persistence of the Middle Palaeolithic and Neandertals in Iberia: A review of the evidence for and against the “Ebro Frontier” model’

A comment on ‘The late persistence of the Middle Palaeolithic and Neandertals in Iberia: A review of the evidence for and against the “Ebro Frontier” model’ by Zilhao (2021, Quaternary Science Reviews 270:107098). This article corrects errors Zilhao made in his interpretations of the Lapa do Picareiro sedimentological and archeological data

Late Pleistocene Landscape and Settlement Dynamics of Portuguese Estremadura

Here we report the results of an integrated geoarchaeological survey to study Palaeolithic human settlement dynamics in the coastal region of Portuguese Estremadura. The region has been an important focus of human occupation across multiple glacial-interglacial cycles, including periods of well-documented abrupt climate instability during MIS 3 and 2. The pedestrian survey covered a roughly 10 km wide strip of land between Sao Pedro de Muel and Peniche. The survey intensively targeted three landscape settings with Pleistocene-age surfaces and sediments: the coastal bluffs with exposed aeolian, fluvial, and colluvial sands; the Caldas da Rainha diapiric valley and associated fluvial/estuarine fills; and, Cretaceous chert-rich limestone uplands that bound the inland margin of the study area. We discovered dozens of new Palaeolithic sites, analyzed numerous Pleistocene sedimentary sections, and applied widespread OSL-dating to establish age control that allowed us to build a regional geomorphic history to contextualize Late Pleistocene human settlement across the region.info:eu-repo/semantics/publishedVersio

Human Occupation during the Late Pleniglacial at Lapa do Picareiro (Portugal)

During Marine Isotope Stage (MIS) 2, abrupt climate changes created highly variable paleoenvironments inhabited by human populations across the Iberian Peninsula. Pollen and sedimentary analyses from deep-sea cores off Portugal provide records of regional-scale paleoenvironmental responses to the climate shifts that punctuated this period. Archaeological assemblages offer a regional and local-scale understanding of human- environment interactions during this period. One site in particular, Lapa do Picareiro, has yielded a continuous, stratified sedimentary sequence that provides a diachronic record for MIS 2 human occupation and environmental change. Here, we present archaeological data from the Late Gravettian through Solutrean occupations (Levels U-O) in order to show how local-scale, assemblage-level variability may or may not help our understanding of human-environment interactions and culture change during this period when we try to fit them into the traditional techno- typological framework. Lithic artifact assemblages record the technological changes associated with the Last Glacial Maximum (LGM), including the Gravettian-Solutrean transition. Age control is provided by 23 radiocarbon dates from Levels U-O. The spatial distribution of artifacts, animal bones and charcoal concentrations shows a relatively high degree of assemblage integrity. The taphonomic study of the faunal remains informs on local paleoenvironments and human diet choice during the LGM. The combined results are used here to understand human responses to long-term environmental change in central Portugal