Bipolar flaking as a component of a supraregional lithic resource base: A comparative study of cores from the Pampean and Northcentral Patagonian Atlantic coasts (Argentina)

Several authors argue that bipolar technology is an expeditious and versatile strategy, efficient for the reduction of small nodules. However, few studies analyze the use of bipolar reduction in relation to the lithic environmental supply. At the Pampean and Patagonian maritime coast, the technique has been widely recorded and seems to be conspicuous in indigenous populations that occupied coastal areas. With the aim of assessing and comparing the application of bipolar reduction, 196 nuclei recovered from sites of diverse chronologies in the Pampean and northcentral Patagonic coasts were analyzed. The use of the bipolar technique was observed in relation to the lithic environmental structure, the size of nodules and their raw material. The results revealed high frequencies of bipolar nuclei at the Pampean coast (87%) and moderate frequencies at the northcentral Patagonic coast (39%). It was determined that the variables that influenced the application of bipolar techniques the most were the small size of the nodules and their rounded shape, generally thick, and without flat surfaces. As for raw material quality, the technique was applied on good to medium quality rocks at the Pampean coast, while in the northcentral coast it was exclusively applied on pebbles and cobbles of superior qualities (very good to excellent). The differences observed are most likely linked with technological choices made by different coastal populations to make the best use of widely available local rocks.Fil: Banegas, Anahi. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bonomo, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gomez Otero, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The El Masnou Infralittoral sedimentary environment (Barcelona province, NW Mediterranean Sea): morphology and Holocene seismic stratigraphy

A detailed analysis of the morphology and the Holocene seismic and sequence stratigraphy and architecture of the infralittoral sedimentary environment of the El Masnou coast (Catalonia, NW Mediterranean Sea) was carried out using multibeam bathymetry and GeoPulse seismic data. This environment extends down to 26-30 m water depth, and is defined morphologically by two depositional wedges whose seafloor is affected by erosive furrows, slides, fields of large- and small-scale wavy bedforms, and dredging trenches and pits. Erosive terraces are also identified in the transition domain toward the inner continental shelf. The Holocene stratigraphy of the infralittoral environment is defined by two major seismic sequences (lower and upper), each one formed by internal seismic units. The sequences and units are characterised by downlapping surfaces made up of deposits formed by progradation of coastal lithosomes. The stratigraphy and stratal architecture, displaying a retrogradational arrangement with progradational patterns of minor order, were controlled by different sea-level positions. The stratigraphic division represents the coastal response to the last fourth-order transgressive and highstand conditions, modulated by small-scale sea-level oscillations (≈1-2 m) of fith to sixth order. This study also highlights the advantage of an integrated analysis using acoustic/seismic methods for practical assessment of the anthropogenic effects on infralittoral domains based on the association of marine geological observations

Human Processing of Rodents in Patagonia: The Relevance of Historical and Ethnographical Data for Archaeological Interpretations

The consumption of small mammals was a widespread practice between indigenous societies worldwide. Modern taphonomic studies carried out upon bone assemblages from archaeological sites in northern Patagonia (Argentina) demonstrate thatCaviomorph rodents were also included in the diet of Patagonian populations, both from the steppe and the forests, at least since the Late Holocene. The revision of historical and ethnographical documents written by priests, naturalists and ethnographers during c.XVI-XX allow to corroborate that rodents were intensively exploited in Patagonia, continental and insular. Bones, meat and skin of the animals were employed for diverse purposes, and the gathering activity was guided by women and children.Fil: Andrade, Analia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Ciencias Sociales y Humanas; Argentin

Evolución geológica en la cuenca baja del río Colorado durante el cenozoico, Patagonia Norte, Argentina

Climatic changes and eustatic sea levels have been assumed to be the most important controllers of the Colorado River alluvial fan in northern Patagonia. Although the alluvial fan occurs in a region considered tectonically stable, there are pieces of evidence that the Miocene Andean orogeny has reactivated inherited structures, with subsequent geomorphological changes that date back to the Pleistocene. Besides, the clear evidence of neotectonism in the region and their effects on the evolution of this fan, it has not been studied in detail yet. In this study, we map and analyze six sections outcropping in different terraces of the alluvial fan with the primary aim of disentangling the role of tectonism, climate and eustatic changes on the evolution of the alluvial fan. This study is part of a bigger project aimed to understand the origin of the shallow lakes occurring in northern Patagonia. Our results indicate that the alluvial fan of the Colorado River was established in the area around the Middle Pleistocene. Evidence of deformations in Miocene to Pleistocene units indicates significant neotectonism during the Upper Pleistocene. By the Pleistocene-Holocene transition, tectonism produced incision generating a set of terraces. After this time, an important climate change from semiarid to arid favored the calcretization of some terraces. By the Pleistocene-Middle Holocene, the terraces were covered by ancient eolian sediment accumulated during dry conditions. By the Middle Holocene, a broad alluvial fan developed in the region under a warmer and more humid climate generating the Alluvial Colorado River-III deposit at the T3 terrace. In the late Holocene, aggradation process was favored by a high sea level and temperate-arid climate, producing T4 terrace. At the same time, this climate condition favored the local deflation-sedimentation processes that resulted in the deposition of modern eolian deposits (mE) over the T3 terrace. The depressions generated by the deflation were, later on, occupied by shallow lakes when the climate turn more humid. Subsequently, during regressive sea level condition, ca. 2000 years BP, the T4 terrace was partially eroded and the modern alluvial plain formed.La evolución geológica y morfológica del abanico aluvial del río Colorado en el norte de Patagonia ha sido explicada, en su zona distal, como resultado de cambios eustáticos y climáticos. A pesar de que el abanico se encuentra en una región considerada como una zona tectónicamente estable, hay evidencia de que la orogenia andina durante el Mioceno reactivó estructuras preexistentes y produjo cambios geomorfológicos asignados al Pleistoceno. Sin embargo, la influencia de la tectónica en la evolución del abanico aluvial del río Colorado no ha sido aún estudiada. En este trabajo, se levantaron y estudiaron seis secciones que afloran en distintas terrazas del abanico aluvial del río Colorado con el objetivo principal de comprender el rol de la tectónica, los cambios climáticos y eustáticos en la evolución del abanico aluvial. Este estudio es parte de un proyecto mayor que busca entender el origen de las lagunas someras presentes en la parte norte de la Patagonia. Nuestros resultados indican que el abanico aluvial del río Colorado se estableció en el área alrededor del Pleistoceno medio. La evidencia de deformaciones en las unidades del Mioceno al Pleistoceno indica una significativa actividad neotectónica durante el Pleistoceno superior. Para la transición Pleistoceno-Holoceno, el tectonismo generó una serie de terrazas. Posteriormente, un cambio climático de semiárido a árido favoreció la calcretización de las terrazas. Durante el Pleistoceno-Holoceno medio, las terrazas fueron cubiertas por la acumulación de sedimentos eólicos antiguos en condiciones de clima seco. En el Pleistoceno medio se desarrolló un amplio abanico aluvial en la región, en un clima más cálido y húmedo, que generó los depósitos aluviales del río Colorado-III en un nuevo nivel de terraza (T3). En el Holoceno tardío, el proceso de agradación fue favorecido por un alto nivel del mar y un clima templado-árido, que produjo la terraza T4. Al mismo tiempo, estas condiciones climáticas favorecieron los procesos de deflación-sedimentación local que dieron lugar a la deposición de depósitos eólicos modernos (mE) sobre la terraza T3. Las depresiones generadas por la deflación fueron, más tarde, ocupadas por los lagos poco profundos cuando el clima se volvió más húmedo. Posteriormente, durante condiciones regresivas del nivel del mar, ca. 2000 años AP, la terraza T4 fue parcialmente erosionada y se formó la llanura aluvial moderna.Fil: Seitz, Carina. Universidad Nacional del Sur. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Vélez, María I.. University Of Regina; CanadáFil: Perillo, Gerardo Miguel E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Geología; Argentin

Steppes, savannahs, forests and phytodiversity reservoirs during the Pleistocene in the Iberian Peninsula

A palaeobotanical analysis of the Pleistocene floras and vegetation in the Iberian Peninsula shows the existence of patched landscapes with Pinus woodlands, deciduous and mixed forests, parklands (savannah-like), shrublands, steppes and grasslands. Extinctions of Arctotertiary woody taxa are recorded during the Early and Middle Pleistocene, but glacial refugia facilitated the survival of a number of temperate, Mediterranean and Ibero-North African woody angiosperms. The responses of Iberian vegetation to climatic changes during the Pleistocene have been spatially and temporarily complex, including rapid changes of vegetation in parallel to orbital and suborbital variability, and situations of multi-centennial resilience or accommodation to climatic changes. Regional characteristics emerged as soon as for the Middle Pleistocene, if not earlier: Ericaceae in the Atlantic coast indicating wetter climate, thermo-mediterranean elements in the south as currently, and broad-leaf trees in the northeastern. Overall, steppe landscapes and open Pinus woodlands prevailed over many continental regions during the cold spells of the Late Pleistocene. The maintenance of a high phytodiversity during the glacials was linked to several refuge zones in the coastal shelves of the Mediterranean and intramountainous valleys. Northern Iberia, especially on coastal areas, was also patched with populations of tree species, and this is not only documented by palaeobotanical data (pollen, charcoal) but also postulated by phylogeographical models

Holocene continental molluscan fauna (Pampean region, Argentina)

In this study the molluscan fauna recovered from six archaeological sites of the Interserrana Bonaerense area is analyzed. Three geographical sectors were studied in this area: I) Middle river basin of Quequén Grande river; II) Southwest of the Interserrana area, and III) Upper river basin of the Tapalqué stream. The systematic review of the continental mollusks recovered was complemented with quantitative, stratigraphical and chronological data for each site since the early Holocene until the present. Additionally, ecological requirements and modern distribution patterns of the taxa recorded were considered in order to search for eventual palaeoenvironmental variations in space and time. A total of 15 taxa (14 Gastropoda and one Bivalvia) were identifi ed in the Luján Formation deposits from southeastern Buenos Aires Province. The fi rst Holocene records for “Aplexa” minor (d’Orbigny), Drepanotrema kermatoides (d’Orbigny), Antillorbis nordestensis (Lucena), Omalonyx unguis d’Orbigny and Pisidium sp. are reported in the Bonaerese Interserrana area. Overall, the mollusks suggest palustrine habitats at the beginning of the early Holocene. During the middle Holocene, they suggest higher humidity (increase of the precipitation pattern) ca. 4.9 kyrs BP and ca. 4.7 kyrs BP. At the beginning of the late Holocene they indicate a general arid trend interrupted by brief humid episodes registered ca. 2.5 kyrs BP and ca. 2.2 kyrs BP. The integration and correlation of molluscan records in spatial and temporal scales allowed recognizing geographical displacements (i.e. Retidiscus reticulatus Fonseca & Thomé) which represent biotic responses to Holocene climate variations as well as local environmental differences for stratigraphical sequences of similar chronologies.No presente estudo é analisada a malacofauna proveniente de seis sítios arqueológicos da área Interserrana Bonaerense. Foram estudados três setores geográfi cos desta área: I) bacia média do río Quequén Grande; II) sudoeste da área Interserrana e III) bacia superior do arroio Tapalqué. A revisão sistemática dos moluscos continentais recuperados foi complementada com dados quantitativos, estratigráfi cos e cronológicos de cada sítio desde o Holoceno inicial até a atualidade. Adicionalmente, foram considerados os requerimentos ecológicos e os padrões de distribuição moderna dos táxons a fi m de inferir eventuais variações paleoambientais. Um total de 15 táxons (14 Gastropoda e um Bivalvia) foram identifi cados nos depósitos da Formação Luján do sudeste da Província de Buenos Aires. Se dão a conhecer os primeiros registros holocênicos de “Aplexa” minor (d’Orbigny), Drepanotrema kermatoides (d’Orbigny), Antillorbis nordestensis (Lucena), Omalonyx unguis d’Orbigny e Pisidium sp. para a área Interserrana. Os moluscos sugerem, em linhas gerais, características palustres na base do Holoceno inicial. Durante o Holoceno médio, eles sugerem maior umidade (incremento no padrão de precipitações) ca. 4,9 ka AP e ca. 4,7 ka AP. No início do Holoceno fi nal, os moluscos indicam una tendência árida interrompida por eventos úmidos curtos ca. 2,5 ka AP e ca. 2,2 ka AP. A integração e correlação dos registros de moluscos em uma escala espacial e temporal permitiu reconhecer deslocamentos geográfi cos (i. e. Retidiscus reticulatus Fonseca & Thomé), os quais representam respostas bióticas às variações climáticas do Holoceno assim como diferenças ambientais locais em sequências estratigráfi cas de cronologias correlacionáveis.Fil: Steffan, Pamela Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Pcia.de Bs.as.. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Aguirre, Marina Laura. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Miquel, Sergio Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Hunting technology during the early and middle holocene in the puna of Salta (Argentina): patterns of variation and processes of change

Se presenta un modelo sobre el cambio en la tecnología de caza en la puna de Salta a lo largo del Holoceno temprano y medio, focalizando en el cambio en la representación de sistemas de armas. Para esto, se siguió una metodología centrada en el análisis de tendencias centrales y de dispersión en diferentes variables diagnósticas de sistemas de armas, medidas en puntas de proyectil. A partir de los patrones resultantes se discuten posibles cambios en las técnicas de caza y la incidencia de mecanismos tales como la toma de decisión y la transmisión cultural en la dinámica de cambio. A su vez, los resultados obtenidos son comparados con los de otras áreas de los Andes Centro-Sur, en perspectiva macrorregional.We present an initial model on the change in hunting technology in the Puna of Salta during the early and middle Holocene, focusing on the change in the representation of weapons systems. For this, we followed a methodology based on the analysis of central tendency and dispersion in different diagnostic variables of weapon systems, measured in projectile points. Changes in hunting techniques and the impact of mechanisms such as decision making and cultural transmission in the dynamics of change are discussed from the resulting patterns. In turn, the results are compared with other areas of the South Central Andes from a macro-regional perspective.Fil: Restifo, Federico. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Arqueología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Los cambios ambientales durante el Holoceno Superior en el norte argentino y su relevancia e interacción con la arqueología.

Se presenta el estado de los conocimientos sobre los cambios ambientales ocurridos durante el Holoceno Superior en el Noroeste Argentino, con un enfoque especial hacia los procesos dominantes en áreas de estudio seleccionadas, las principales tendencias que se observan en la morfodinámica durante el período bajo estudio y su relevancia para la arqueología. Se escogieron tres áreas de estudio, ubicadas en la Puna de Jujuy, en las Sierras Subandinas y en el Chaco. Los resultados obtenidos muestran que el paisaje ha sufrido cambios morfodinámicos muy importantes, controlados tanto por procesos que obedecen a causas naturales, como por factores antrópicos ligados al uso del territorio, tales como variación de la cobertura vegetal (por uso ganadero, agrícola, incendios), manejo del recurso hídrico, entre otros.This paper shows the state of the knowledge about environmental changes that took place during the Late Holocene in Northwest Argentina, with a special focus on the dominant processes in the selected study areas, the main trends observed in the morphodynamics during this period and its relevance for archaeology. Three study areas were selected, located in the Puna, Sierras Subandinas and Chaco. The results show that the landscape experienced very important morphodynamic changes, produced both by natural processes and human factors related to land use, such as changes in land cover (for livestock breeding, agricultural uses, fires), water resource management, among others.Fil: Kulemeyer, Julio José - Facultad de Ingeniería, Universidad Nacional de Jujuy

Processes of diversification, intensification and domestication during the holocene in the highlands north of Argentina and Chile: contributions from the puna of Salta

Este artículo analiza y discute los procesos de intensificación, domesticación y diversificación en el uso de los camélidos ocurridos entre ca 10000 y 3500 años AP en la Puna de Salta, comparando con distintas áreas de las tierras altas del Noroeste argentino y el Norte de Chile. La información arqueofaunística y lítica macroregional disponible se integra para el estudio de estos procesos. Los resultados indican cambios en el Holoceno medio y, fundamentalmente, en el Holoceno medio final. La evidencia faunística registra la presencia de camélidos domesticados y el aumento en la representación de camélidos subadultos, mientras que la tecnología lítica se caracteriza por la presencia de una mayor variedad de puntas de proyectil y la proliferación de formas base de hojas.Intensification, domestication and diversification processes on the use of the camelids in the Puna of Salta (ca 10000 - 3500 BP) are comparatively analyzed and discussed in this article considering different areas from the highlands of the Northwest of Argentina and North of Chile. Thus, archaeofaunal and lithic information is integrated to the study of these processes. Results highlight the occurrence of changes during the Middle Holocene and especially in the end of the Middle Holocene. The archaeofaunal evidence exhibits the presence of domesticated camelids and an increase in sub-adult camelid frequency throughout the Holocene. In relation to lithic assemblages, an increment in projectile point classes and the proliferation of blade technology are recorded.Fil: Lopez, Gabriel Eduardo Jose. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Arqueología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Restifo, Federico. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Arqueología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Osteometry and camelid bone identification in archaeological sites of the sierras Centrales, Argentina:. trends, problems, and perspectives

La probable presencia de camélidos domésticos en el Holoceno tardío de las Sierras Centrales (Argentina) -y su probable significado económico- define problemas poco desarrollados por la arqueología regional. Estudios osteométricos previos, efectuados sobre huesos provenientes de contextos arqueológicos de distintos momentos del Holoceno, han permitido: 1) establecer el rango de variación morfométrica durante el Holoceno temprano y medio, interpretado como representativo de la población local de guanacos (Lama guanicoe), actualmente extinta; y 2) constatar la ampliación de dicho rango durante el Holoceno tardío, fenómeno oportunamente relacionado con la introducción de camélidos domésticos (i.e., llamas, Lama glama). En esta oportunidad evaluamos nuevamente dicha propuesta luego de incrementar los restos óseos de camélidos sujetos a mediciones, sobre todo del Holoceno temprano y medio. El estudio se focalizó en el análisis univariado y bivariado de la porción proximal de falanges primeras, un hueso que es frecuentemente recuperado en los contextos arqueológicos y que se considera discriminativo para diferenciar especies de camélidos. Los resultados señalan la amplia variabilidad en el tamaño de los camélidos del Holoceno de las Sierras Centrales, información que permite precisar las tendencias observadas anteriormente y especificar las limitaciones de la técnica osteométrica para discriminar entre L. glama y L. guanicoe en conjuntos arqueofaunísticos del centro de Argentina.The probable presence of domestic camelids in the Late Holocene of the Sierras Centrales, Argentina, and their probable economic significance is poorly developed in regional archaeology. Osteometric studies carried out on Lama sp. bone assemblages from Holocene archaeological deposits have resulted in: 1) the establishment of the morphometrical range variation of local Early and Middle Holocene Lama guanicoe populations, now extinct; and 2) the verification of a sudden range increase during Late Holocene, which was related to the introduction of L. glama. These proposals are evaluated here in the light of new osteometrical measurements of camelid bones, mainly from Early and Middle Holocene deposits. The study focuses on univariate and bivariate analyses of the proximal first phalanx, a bone recovered at high frequency in the archaeological record and seen to be particularly effective in discriminating between species of camelids. The results show a high metric variation in Holocene camelid bones from the Sierras Centrales. This information was used to specify previously observed trends as well as test the effectiveness of the osteometric technique in making distinctions between L. glama and L. guanicoe from central Argentinean archaeofaunal assemblages.Fil: Medina, Matias Eduardo. Centro de Estudios Históricos ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pastor, Sebastián. Centro de Estudios Históricos ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rivero, Diego Eduardo. Centro de Estudios Históricos ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin