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In order to understand the paleogeographic evolution of Viedma Lake (252 masl) sedimentary sequences with glaciolacustrine and lacustrine strata between 307 masl and 266 masl and bathymetric fluctuations between 27 ka. and 2.4 ka. were identified. The paleoenvironmental interpretation of the stratigraphic profiles was carried out based on the analysis of facies and their associations. The oldest age was recorded at 301 masl (27 ka) and the youngest corresponds to 266 masl (2.4 ka). The record of 27 ka was compared with another dated record of the Tar-San Martin Lakes basin showing that Viedma – Tar-San Martín Lakes were formed at similar ages. Taking into account that the deposits of Bahía Túnel are located at 266 masl and that the level of the lake would be above this height, it is proposed that this lake level would have restricted the movement of hunter-gatherer populations along the coast and to the west. From 2.4 ka on a new space started to be available for these populations broadening the wintering grounds (≤400 masl). The chronology of the archaeological record found in this new space fits the proposed paleogeographic evolution. This paper complements the research on the evolution of lacustrine systems in the Patagonian Mountain range and broadens the discussion of human mobility in the Viedma Lake basin during the Holocene. [ABSTRACT FROM AUTHOR]

The aim of this study is to assess the variability of the stable carbon and nitrogen isotope composition of herbivores -guanaco and huemul-in southern Patagonia. The study area extends from the eastern slopes of the Andes to the Atlantic Coast between 47° and 49° S. The ultimate aim of the research was to generate an isotopic ecology with an adequate spatial resolution that allows the incorporation and development of stable isotope studies in discussions of the population dynamics of hunter-gatherers in continental Patagonia. This paper presents the δ13C and δ15N values of 159 guanaco and huemul specimens, both modern and archaeological. This space was divided into three areas: Western area, Central Plateau and Eastern Area. Isotopic variability within groups was analyzed using the SIBER, from which the isotopic niches of the different groups are compared. The results show a spatial pattern of isotopic variability in herbivores, i.e. lower δ13C and δ15N values associated with forest environments in the western end of the transect and higher values, especially δ15N, towards the east, with maximum values observed near the Atlantic coast. Our results support the stated expectations on herbivore stable isotope composition variability and its association with environmental variables in a longitudinal transect across the southern Argentinean Patagonia. [ABSTRACT FROM AUTHOR]

Abstract The main aim of this paper is to evaluate if certain processes that were documented in a specific area of Central-Southern Patagonia during the Late Holocene were also registered in a broader spatial scale. Previous investigations carried out in our study area located in Central-Western Santa Cruz province, Patagonia, have stated that climatic fluctuations during the Late Holocene (last 2500 years) were the cause of a reduction of hunter-gatherers' residential mobility. The new climatic conditions were characterized by important environmental droughts, which increased during the Mediaeval Climatic Anomaly, circa 900 years BP. This reduction in mobility resulted in concentrations of populations in low altitude basins and increased logistical and seasonal mobility, defined as a process of extensification. In this paper we take a broad spatial perspective to evaluate to what extent the low residential mobility identified in our research area had a correlation in a larger regional scale. Also we assess if this lead to a regional differentiation among hunter-gatherer populations, previous to European contact (450 years BP). In order to achieve these aims, we undertake a coarse grain analysis, using available data published on the composition and distribution of the archaeological record for Central-Southern Patagonia, an area of about 450.000 km2. Specifically, we consider evidence about technology, zooarchaeology, rock art, mortuary record and paleodietary studies. The analysis indicates that a reduced residential mobility could have occurred in certain areas of the study region, linked to the aforementioned climatic changes. On the issue of regional differentiation, the archaeological record highlights the complexity of this process. There are a variety of arguments both for and against the idea of a process of regionalization in Central-Southern Patagonia in the Late Holocene. We propose a process of differentiation of populations with low residential mobility which nonetheless remained connected through the circulation of goods, information and people. [ABSTRACT FROM AUTHOR]

Several foodborne diseases have been described in coastal populations from the past, many of them including parasitic infections related to marine diets. Considering this background, the strong relationship between hunter-gatherers from Patagonia and the marine species implies a possible source of parasitic infections and zoonotic risk. However, marine parasitic species have not been identified in archaeological sites from Patagonia so far. The aim of this paper is to propose the potential parasitic infections produced by the consumption of marine molluscs, fishes, birds and sea mammals by human populations from Patagonia during the Holocene, considering the current parasitic species identified in the Southern Atlantic Ocean. We searched in journal articles and book chapters for references of archaeological remains of molluscs, fishes, seabirds and marine mammals recorded in archaeological sites from the Atlantic coast below the 42nd parallel South. Afterwards, we surveyed all the macroparasites of marine origin identified by current parasitological research in the same species found in the archaeological record. We found that most of the marine species in the zooarchaeological record of Patagonia are currently hosts of many parasites. Some species of molluscs, fishes and pinnipeds are highly infected by larvae that are potentially hazardous for human health. Some of them are responsible for acute or chronic zoonotic diseases, with severe consequences depending on how the food was cooked, the amount of consumed parasites and the immune response of the host, in this case, humans. Fishes are host of several parasites related to anisakidosis and corynosomiasis. Sea lions species were also a potential source of the same zoonosis but also diphyllobothriasis. Molluscs are hosts of several parasitic species, but with less severe consequences for human health. On the other hand, birds are infected by adult parasites, without direct zoonotic importance. These findings, although limited by temporal and environmental variability, can provide a speculative overview about the potential influence of marine diets in the health of past hunter-gatherers of Patagonia, particularly if fishes, molluscs or marine mammals were consumed inadequately cooked. [ABSTRACT FROM AUTHOR]

Central Western Patagonia (CWP) is a key area for assessing long-distance procurement of high-quality obsidians throughout the Holocene given that almost all relevant types represented in the archaeological record are exotic to this region. By using surface and stratigraphic obsidian artifacts from archaeological sites compared to standards from known sources in Patagonia, this paper discusses the spatial and temporal distribution of this lithic material. Sampling was oriented to assemblages from deposits with radiocarbon-based time frames (10,700 − 300 cal BP). This paper presents geochemical (ICP-MS) analyses of 178 samples from 58 archaeological sites at 11 surveyed areas located along the Pacific coast, the Andean forest, and eastern steppe. Out of six potential sources, the Chaitén Volcano source (Los Lagos Region, Chile) dominates exclusively the occurrence of obsidians along the coastal fringe, while the Pampa del Asador source (PDA, Santa Cruz Province, Argentina) largely dominates (86% of samples) obsidian in the eastern steppe and the forest/steppe ecotone. This broad distribution is explained by the presence of the densely forested Andean mountain range acting as a biogeographical barrier. East of the Andes, we recorded an absolute dominance of PDA south of 45°30′S, while more variability prevailed north of this point. The highest diversity of obsidians was recorded in the Cisnes River valley, probably because it is located closer to other alternative northern sources (Telsen/Sierra Negra, Sacanana and Angostura Blanca, all in Chubut Province, Argentina) and because it also hosts a local low-quality obsidian type. Based on this distribution, we discuss obsidian procurement behaviors by considering obsidian frequency and tool/debitage-class representation with increasing distance. We use the analysis of fall-off curves based on the distance of studied locations from the sources and include the use of least-cost paths for providing the most likely procurement routes. No obsidian diversification was recorded during the Holocene, hence the main driver for its procurement seems to be the distance from the source rather than the antiquity of its knowledge. Alternative procurement behaviors are discussed, specifically direct acquisition, exchange, and/or sporadic visits as mechanisms for explaining the archaeological patterns throughout the Holocene. [ABSTRACT FROM AUTHOR]

This paper presents the paleogeographic reconstructions of flooded areas of the Tar - San Martín lacustrine system during the late Pleistocene - Holocene. The dimensions of lacustrine and glaciolacustrine levels of this basin are higher than the current levels of the lakes. The organic matter of lake levels recorded on stratigraphic profiles was described, sampled and dated using AMS, while other paleobathymetric indicators were also identified (height of the fan-delta apex and paleo-coast levels). Deriving out of the reconstruction of flooded areas it was established that the lake system was formed before 28 ka ago and would have reached its maximum expansion around 12 ka ago. The first hunter-gatherer occupation of the basin (11 ka) corresponds to the period of initial contraction of the lake system and the composition of the current configuration of the coastlines. This scenario would have allowed the exploration of western areas and the gradual incorporation of the forest to the action range of hunter-gatherer populations. Similarly, the levels of lakes Tar and San Martín would not have hindered the movement of human populations through the steppe throughout the Holocene. [ABSTRACT FROM AUTHOR]

In this paper, the analysis of a radiocarbon database of the North Coast of Santa Cruz (central Patagonia, Argentina), is presented. Dated archaeological samples were obtained from 56 different types of archaeological sites (open-air -residential sites and burials-, and also rock shelters). The objective of this paper is assessing the continuities and discontinuities in the chronological signal of the area and identifying tendencies along the Holocene. The database currently contains 75 radiocarbon dates falling between ca. 8000 and 300 BP. The radiocarbon data base provides information on the chronological, spatial and contextual variability of the archaeological record of North Coast of Santa Cruz. By means of different analysis of sum of probabilities, we present three different chronological moments of human use of the coast and intermediate zone can be identified. A first moment is represented by early evidence of settlement during Middle Holocene. A second moment corresponds to a hiatus between ca. 5800 and ca. 3900 BP without archaeological evidence. Finally, a third moment is where an increasing of chronological signal occurred, related to greater artifactual variability and an increase in the intensity of human settlement in the Patagonian region. The causes that could have influenced in the discontinuity of the chronological signal of the study area, and the characteristics of the different moments identified are discussed. [ABSTRACT FROM AUTHOR]

In this paper, we analyze the lithic assemblages from three sites from the Central Plateau of Santa Cruz in the Argentine Patagonia. Functional analysis was combined with a techno-morphological and distributional approach, the investigation on raw materials and the study of the technological strategies of production and consumption. The significance of combining functional analysis with other research methods involving lithic remains is emphasized. By articulating different methodologies, it is possible to understand the systems of technological organization. Two sites refer to Final Pleistocene occupations (Cerro Tres Tetas 1 and Casa del Minero 1). The integration of approaches showed the diversity of strategies developed in the production and use of tools, as well as the existence of activity areas within the sites. The third site is a Middle Holocene context (Cueva 13 of Los Toldos). The combination of perspectives allowed a redefinition of the toolkit structure and showed that blade production was part of a standardized technological system. [ABSTRACT FROM AUTHOR]

This paper presents the first attempt at qualitatively and quantitatively evaluating the sedimentary contribution of the Puna plateau to the loess and soils of the Argentinean Pampas. The origin of the Pampean sediment has been traditionally ascribed to northern Patagonia, but new evidence supports a dual supply: western Central Andes/North Patagonia and Puna/Altiplano Plateau. Three different lines of evidence show here that Puna dust supply is active and produces significant sedimentary deposition up to places like Buenos Aires city. The first evidence is meteorological and we show here one event related to an abnormal rainfall that deposited large quantities of a reddish-brownish silt eroded out from the Puna, calling the attention of the environmental agency of Buenos Aires city. The second evidence is the sampling of active wind transport collecting extremely coarse material carried out in the saltation layer, suggesting the fine grained material escapes the area as fugitive dust. This also demonstrates that observed gravel-bearing bedforms of the Puna are active, and that the transport system seems to be activated by polar fronts only. Results show that the saltation curtain is abnormally thick and coarse, suggesting that the kinetic energy peaks ca. 7–10 times higher than for normal saltation, while the transported grain size coincides with the lagged sediment in this basin composing different bedforms, varying between sandy gravel and gravelly sand. The third evidence is the quantification of the exported material by defining a reference surface as the initial time of evolution, and the present day surface. The initial surface is an alluvial surface of an estimated age of 11–12 ka. BP. Volume balance was achieved by a detailed topographic, stratigraphic and geophysical survey, reconstructing old alluvial and present surfaces. Two gridding methods were used, and more conservative results of the volume balance, indicate a total erosion of ca. 3.386 hm 3 of sediment in 72 Ha, spliced in 0.963 hm 3 of sediment that was left within the place forming gravel dunes, while the remaining volume of ca. 2.423 hm 3 is sediment truly exported from the surveyed area. Results imply a continuous blanket of ca. 4 m thick of sediment exported out of this basin in the Holocene. These findings prove that the Puna contribution to the Chaco-Pampean plain is significant, although not unique. Thus, true proportions of sediment contribution to soils and loess from these multiple sources should be better evaluated in future studies. [ABSTRACT FROM AUTHOR]

In this paper we focus on the regional/local scale of the archaeological record of the Central-West area of Chubut (Argentinean Patagonia) through the characterization of its regional taphonomy, considered from an archaeological perspective. We focus our research in the comparison of three different landscape situations: 1) a slope leading to highlands, 2) an azonal vegetal community (wetland or mallín ), and 3) a salt lake. Our main goal is to compare those situations, in order to determine the main taphonomic factors that regulate the archaeological material distribution in those locales. The ultimate goal is to address how past hunter–gatherers inhabited these landscapes. We depart from the assumption that distributions of artifacts are mainly explained by the action of post-depositional processes. To evaluate this assumption first we postulate a series of hypothesis and expectations for each locale, considering the main post-depositional agents present in them, and we evaluated if the patterns of material distributions can be explained by one or many of those processes. Only if explanation cannot be achieved by them, we recurred to human depositional activities. As a result we managed to explain most of the archaeological distributions in terms of post-depositional processes. Only in two cases we propose that human deposition occurred. [ABSTRACT FROM AUTHOR]

Abstract: This paper compares two zooarchaeological sub-samples, each of which comes from a different area (North chamber and South chamber) of Maripe Cave Site (Santa Cruz, Argentina). In previous papers, each chamber was interpreted as a particular microenvironment based on their specific environmental and geoarchaeological features. In both areas, hunting–gatherer society occupations were recorded since the Pleistocene–Holocene transition to late Holocene. This paper investigated and discussed the different agents and processes involved in the formation of each assemblage, with the aim of assessing the taphonomic variability between the two areas and discussing their integrity. Bone specimens of Lama guanicoe (guanaco), the most common species on the site, were analyzed. The bone surfaces of specimens were studied by naked eye observations and binocular magnifying to 10×, which allowed recognition of different patterns of modification. The representation of guanaco anatomical units was also discussed at each chamber according to economic utility and BMD values. The results indicate that while there was involvement of different natural agents and processes acted differently in each sector, the main accumulating agent in both sets was human. Differences between both chambers are observed in the representation of anatomical units, in processing marks, in the conservation of specimens, and in the number and intensity performed by each natural agents and process in each sector. Each chamber indicates a different taphonomic history: the North Chamber records greater conservation and archaeological integrity, while the South Chamber shows a more complex taphonomy. [Copyright &y& Elsevier]

The purpose of this paper is to begin to understand human mobility through rock transport at different times in two areas with different environmental characteristics: the Southern Deseado Massif and the basaltic canyons north of the Santa Cruz River. We focus on obsidian, which has a clear geochemical signature and an uneven distribution. Additionally, we use macroscopic information on siliceous rocks, which at present have only been identified in northern areas, although they may also be recovered randomly and in low frequencies in southern ones. During the initial peopling of the Southern Deseado Massif (ca. 10,800 BP), inhabitants were transporting black obsidian as well as translucent chalcedony, probably as part of the individual gear. During the Late Holocene, the number of obsidian artifacts decreased in the Southern Deseado Massif, related to a better knowledge of the high-quality local lithic resources and/or to the existence of higher population densities. Obsidian artifacts are more abundant in the northern Santa Cruz River basin than in the southern Deseado Massif, suggesting the existence of a relationship with areas located to the northwest, close to the obsidian source, as other lines of evidence suggest. In addition, the presence in the basaltic canyons of artifacts made from high-quality siliceous rocks, more abundant and predictable in northern areas, could also be the result of human movements following a north-south direction. [ABSTRACT FROM AUTHOR]

Archaeological radiocarbon databases are being increasingly used as a proxy of past demographic trends. In this paper we compile and analyze an extensive database of paleoecological information and 14 C dates from archaeological sites in northwestern Patagonia (Argentina, South America). On this basis, we assess the regional distribution of human populations since the late Pleistocene, and their relation with the evolution of Patagonian climate and landscapes. We explore the spatial and temporal distribution of evidence and discuss sampling biases affecting the record in different ecological contexts. The analysis is set in the frame of three main ecological regions that have implications for human subsistence: Andean forest, grass steppe, and shrub steppe. The intensity of the archaeological signal differs among these regions through time, being stronger and more homogeneous in the grass steppe. In the Andean forest and the shrub steppe the signal is weaker and even absent during short periods of the middle Holocene. We suggest likely sampling biases contributing to these tendencies, since these three regions present variable research cover and intensity. On the other hand, we also suggest that these differences may reflect variations in the intensity of human occupation, in favor of more attractive environments for hunting (i.e., areas where guanaco are generally more abundant). This macro-regional synthesis of the paleoecology and archaeology of northwestern Patagonia provides a platform for developing future oriented research. [ABSTRACT FROM AUTHOR]

This paper summarizes and discusses the main results achieved over three decades of research on paleodemographic aspects of Late Holocene hunter-gatherers in Northwestern Santa Cruz (Argentina). Research has been guided by a model of regional settlement that proposes that, as a result of the progressive aridization process recorded in Patagonia during the Late Holocene, human groups would have reduced their residential mobility and concentrated their settlements in low altitude basins with water availability, such as Lake Cardiel and Lake Salitroso. Paleodemographic questions derived from the model relate to population regional continuity and dynamics and were tested using several lines of research at regional and local scales. The assessment of the chronological information and temporal trends of the archaeological record at the regional level allowed for a coarse grain paleodemographic approach, and acted as a mean to support hypotheses related to changes in mobility and land use strategies. Building on this, several lines of bioarchaeological evidence were used to address paleodemographic aspects of the model, including temporal, distributional, and compositional studies of the mortuary record, isotopic, morphometric and DNA analyses and the sex and age structure of the skeletal samples recovered in Lake Salitroso basin. Results point to a biological and cultural population continuity in the region during the Late Holocene. Also, a reduction in residential mobility would have favored a slight population growth of Lake Salitroso populations during the last millennium. [ABSTRACT FROM AUTHOR]

The archaeo-paleontological site of Pilauco (southern Chile) has one of the richest Late Pleistocene mammal records of the northern Chilean Patagonia, with at least nine forms dominated by gomphothere remains. This site has a complex taphonomic history due to postdepositional processes that affected the integrity, frequency, and distribution of the fossil bones. One of these processes is the action of large carnivores, indicated by tooth marks recorded exclusively in gomphothere bones. In this paper, we describe Gomphotheriidae fossil remains and give a detailed description of carnivore tooth marks detected in the sample. The absence of diagnostic fossil specimens does not allow genus or species assignment. The type, location, intensity, and dimensions of the tooth marks are compatible at least with a large felid, which probably scavenged a partially exposed carcass. The record of this taphonomic feature is important in order to understand the postdepositacional history of the Pilauco site, in which natural and cultural agents are involved. [ABSTRACT FROM AUTHOR]

Abstract: Archaeological deposits in continental Patagonia that allow an adequate discussion of the exploitation of seabirds, particularly the Spheniscidae, are scarce. In many cases, characteristics of bone assemblages seem to indicate the natural incorporation of penguin bones into archaeological contexts. This suggests it is not always possible to support the argument that the presence of penguin remains indicates, a priori, consumption by humans. The Bajada de los Pescadores (BP2) site, San Matías Gulf (Río Negro, Patagonia, Argentina), provides a case study that allows the origin of these deposits and their contents to be evaluated in terms of the exploitation of penguins and other marine resources by hunter-gatherers during the Late Holocene. This paper discusses the origin of the archaeological deposit, its context, and the agents involved in its formation. The analysis used criteria formulated previously in the framework of actualistic taphonomic observations, with the aim of assessing the integrity of this sample, and evaluating its contribution towards clarifying the role of penguins in the subsistence of people on the northern Patagonian coast. [Copyright &y& Elsevier]

Abstract: While the Ensenadan Stage/Age (ca. 2.1 to 0.5Ma) was characterized by certain mammal associations in the Pampean plains, the Andean ranges of Patagonia and Tierra del Fuego, their piedmont areas and, in some cases, the adjacent lowlands were undergoing a well-defined alternating sequence of glacial and interglacial stages driven by the regional climate of Southernmost South America and Antarctica. This paper reviews the available geographical, geological and chronological evidence of glaciation during the Ensenadan stage/age, with perhaps more than 15 distinct glacial events, including the Great Patagonian Glaciation (GPG) and other cold episodes that took place before and after it. Finally, a tentative correlation of Patagonian glacial episodes and the Pampean biostratigraphic stages, based on radiometric dating and paleomagnetic studies, is herein presented. [Copyright &y& Elsevier]

South America appears as a paradox for building the images of the New World''s human colonization. It is a paradox, because according to the models of the Peopling of America, it was the last part of the continent to be occupied by humans, but in spite of that sites as old as or older than the “Clovis” sites from North America, started to be discovered since the last century. It is a laboratory, because the amount of the Pleistocene archaeological sites is as great as their variability. In this way, since the last two decades, the hemi-continent is placed in a privileged situation for questioning and reconstructing theories concerning the first Americans, and also for answering questions as when did they arrive, how did they arrive, what strategies (social, ecological and economic) did they develop for the colonization of such different environments, which were their ideas for achieving this colonization, and how does their use of space and resources reflect in the archaeological record. The model “Clovis the first”, brings an image of unidirectional migration of the first people, from the great North American plains to southern Patagonia. For a decade, this model showed itself insufficient for explaining the great archaeological variability of America and especially for referring those South American contexts directly to a Clovis migration. The new findings in South America are creating more anomalies for this model, which predicts that the arrival of Pleistocene hunter–gatherers should be around 10,000 years in Patagonia. The object of this paper is to discuss these models in view of South American archaeological evidence, and thus propose answers for removing the paradox. The axes which are considered are: the geographical and chronological distribution of the main localities of Patagonia and South America; the function of the sites within regional mobility systems; the use of subsistence resources; the differences in the circulation of lithic raw materials; and the different taphonomical histories. These characteristics will be compared with models of social network among mobile peoples and American paleolandscapes at the Pleistocene/Holocene transition and a new alternative route of peopling in South America will be presented. In this sense, the data of Patagonia are highly relevant. [Copyright &y& Elsevier]

The Pleistocene–Holocene transition was a critical time for the dispersal of human societies all over South America. People looking for places to settle had to accept high environmental variability during the colonizing process. The case studied for this paper is Patagonia (Southern South America), where the oldest dates (ca. 13–10.5 ka BP) have been obtained for the peopling in the Deseado River Basin and Magellan Basin, as well. However, two archaeological sites yielded similar dates on the western side of the Andes (Monte Verde and Tagua Tagua).Following archaeological and palaeoenvironmental data (palynological, faunal, sedimentological and glaciological information), as well as radiocarbon datings, a hypothesis about the colonization of Patagonia is presented. Analysing the ways and time of colonization for this region, it is remarkable the coincidence of these ages in the centre of the steppe and close to the Magellan Strait, even in the present Tierra del Fuego island, though the eastern Andean foothills seems to be occupied at least two millennia later. It is proposed that independent peopling entries would have occurred both through the Atlantic and Pacific facades, and that the Andean foothills were colonized much later, only when the available spaces allowed it. [Copyright &y& Elsevier]