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In Central Western Argentina (CWA), the incorporation of cultigens by hunter-gatherer populations has been much discussed. This paper explores the relationship between population dynamics, subsistence change, and burial patterns driven by the process of land use intensification and increasing reliance on maize. We hypothesize that territorial behavior emerged in the context of population growth and competition for resources with a high probability of failure, as expected in an arid environment. To evaluate this hypothesis, we explore four lines of inquiry in southern Mendoza (CWA): 1) the frequency of radiocarbon dates to estimate population dynamics; 2) the Juvenile Index as a fertility rate proxy; 3) the stable isotopes on human bone (δ 13C co , δ 15N, δ 13C ca) to reconstruct diet; and 4) burial patterns as an estimate of territorial control. Our results partially support our hypothesis: During an early stage, when maize started to appear in the diet, the population was increasing, and cemeteries emerged along with some signs of violence. The hypothesis is not supported in a second period, when maize consumption and population were highest, but large cemeteries disappeared. In light of this evidence, the effect of maize on human societies was not uniform and irrevocable, and the adoption of maize by human foragers contributed to a new and diverse set of human-environment relationships. [ABSTRACT FROM AUTHOR]

This paper explores how significant are the ecological and climatic variables to influence the stable isotopes of guanacos. Lama guanicoe bone collagen carbon and nitrogen stable isotope ratios are assumed as a macro regional average value in west Argentina, mostly as a baseline to model archaeological human diet. If stable isotopes on mammals reflex ecology and climate, we need to know how those variables influence mammals bone stable isotope ratio. This paper analyses the 13C/12C and 15 N/14N ratio on bone collagen on 122 guanacos from Northwest Patagonia during the Holocene. The results confirm significant variation in both isotopes between Monte and Andean-Patagonian specimens. Guanacos from Monte shows higher δ13C and δ15N than those from Andean-Patagonian. Temporal trends indicate variation through Holocene but this variation is not spatially homogeneous. In this paper we suggest that Medieval Climatic Anomaly had stronger effect in Monte desert than in Patagonia desert, generating driest and/or hottest conditions between 1250 and 600 years BP. Those variations need to be considered to reconstruct human diet at least during the second part of the Holocene. [ABSTRACT FROM AUTHOR]

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]

This paper presents the results of a study of firewood use and management by human groups in the Ongamira valley, Córdoba, Argentina (dated between c. 5700-950 BP). In order to understand firewood gathering practices at different periods in the Late Holocene, samples from 63 combustion events recorded in 9 rockshelters were analysed. From the anthracological analysis (14,976 fragments) 19 woody taxa, and 4 botanically indeterminate taxa, were identified belonging to Chaco Serrano forest vegetation. The identification of abundant small flat fireplaces suggests short-lived activities repeated over time. A detailed analysis of the samples (types of fire pits, alterations during combustion and taphonomic processes) permits inferring firewood gathering in the local vegetation around the sites, as well as some taxa belonging to different environmental settings. Archaeological evidence indicates that groups were mobile, with the establishment of a network of places in the landscape where different activities were carried out (tool production, food consumption and pottery manufacture) with fire making as a central activity. People in the past constantly used different places in the valley, focusing many of their activities in rockshelters. [ABSTRACT FROM AUTHOR]

Time resolution of shell middens is normally addressed through estimation of shell accumulation rates, where calculations are based on radiocarbon analysis. Density values by volume or discard rates by time units are also normally estimated for comparative purposes. In this paper, we support the idea that time has many measurable properties in archaeological deposits. These can be used as tapho-chronometric tools (e.g., bone weathering, shell fragmentation, soil formation, etc.) to identify differential time-averaging in shell midden formation, and to evaluate their archaeological implications regarding the material record. One site in the Beagle Channel, Argentina, was chosen to (a) demonstrate how different processes that interact in shell midden formation can provide information on temporal resolution and (b) discuss the implications of the time-averaged properties of shell middens for different analytical approaches and methodological pathways. Results show that several factors involved in the formation of mounds should be addressed prior to advancing interpretations about different behavioral aspects of the past: a) shell deposits do not necessarily represent a gradual accumulation of waste; b) these middens can represent occupations of varied duration that are expressed independently of both the thickness of the deposit and the rate of accumulation of the material; c) the formation of shell middens includes the actions of several cultural and natural processes that occur over variable time spans; d) re-occupations modify the shell deposits produced by previous occupations in the same location. Finally, we argue that to explore shell middens as time-averaged records helps to clarify distinctive aspects of mound formation, which in turn have significant effects on archaeological interpretations. [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 carry out an isotopic study to learn about the diet and mobility patterns of the human groups that inhabited different areas and environments of western Catamarca, Argentina, over almost 2500 years. We present and discuss the results of the isotopic composition of 26 bioarchaeological remains (δ13C and δ15N on bone collagen, and δ13C and δ18O on bone apatite) with their respective calibrated absolute dates, from different settings and elevations of the province of Catamarca. They account for the sociocultural development of both the first agropastoral village societies and the Inca society. We also present the regional isotopic context of autochthonous animal and plant food resources. The isotopic composition (δ13C and δ15N on bone collagen) of 47 samples of pre-Hispanic camelids recovered from archaeological sites located at different altitudes of the Fiambalá and Chaschuil regions are studied and discussed. In addition, the δ13C values of 52 native modern and archaeological plant samples are compiled, including samples from the region as well as information from the bibliography. Finally, isotopic analyses of water samples (δ18O) recovered from different environments in the study region are also shown. The data from δ13C and δ15N on bone collagen and δ13C on bone apatite show a high variability of the human diet of the populations of western Catamarca, and suggest that the societies that inhabited the region during the first millennium AD had a balanced diet that combined proteins and carbohydrates, while those dated after the thirteenth century AD reduced their protein intake, which would have significantly affected their health status. The first trends in the δ18O values indicate that individuals had low mobility patterns during their lives, except for some unusual cases of possible non-local individuals. [ABSTRACT FROM AUTHOR]

Stable isotopes of nitrogen (δ 15N) provide information that can be used to calculate, in a quasi-continuous manner, the trophic position (TP) of organisms within particular food webs. The estimation of the TP is fundamental to analyze cases in which some degree of omnivory is involved. Humans, as a species, are trophic omnivores that use plant and animal tissues as food sources, although in an intraspecific context they tend to significantly vary in their respective degree of omnivory. In archaeology, the use of stable isotopes to infer past diets is widespread; however, the formal assessment of TP is rare. In this paper we describe a method to simultaneously calculate and map the TP of past human populations across large spaces, involving wide environmental variation. This method uses, as inputs, δ 15N isoscapes corresponding to (i) primary producer/s, (ii) a taxon of primary consumers with wide spatial distribution and (iii) humans. The first two isoscapes function as the needed baselines for TP calculation. The approach is exemplified with data from central and southern Argentina and Chile (southern South America, 30°–56° S). [ABSTRACT FROM AUTHOR]

Archaeology has been using stable oxygen as an isotopic tracer linked with water consumption for decades, and it has been demonstrated to be a powerful tool to assess paleomobility in bioarchaeology. Central-eastern North Patagonia (Argentina) is an especially appropriate region to apply it since it presents a high density of hunter-gatherer burials, it was a nodal zone criss-crossed by an extensive network of important routes, and it is characterized by a high environmental fragmentation due to the scarcity of fresh water sources. The aim of this paper is to build an empirical stable oxygen isotope baseline of terrestrial surface waters to assess the potentiality of tracing past human movement. We analyzed 46 water samples from 13 locations with permanent sources (rivers, springs, streams), compared it with predictions of precipitation and evaluated it considering seasonal variation, altitude and distance from the coast. Our results show that different post-precipitation processes change the isotopic signal from the sources with respect to the local precipitation, and highlight the relevance of analyzing terrestrial water sources. According to their oxygen isotope values we defined five hydrologic zones: Colorado River, Negro River, Closed Basins and Plains, Eastern and Western Somuncurá Foothills. Their identification shows the potential to address past human movement using stable oxygen water baselines in central-eastern North Patagonia. [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]

Abstract: In the Deseado Massif there are many stratified archaeological sites located in caves and rockshelters. The cultural sequences, proposed in the past century, include an occupational hiatus and cultural changes that were developed on the basis of large tools from archaeological sites, without debitage analysis. The aim of this paper is to review the current debate on lithic technology and human occupations of this area during the Mid-Holocene, integrating new data, as well as the latest environmental interpretations. The contribution of new information from blade and bifacial technologies is central to discussion of the models proposed by other authors. The new baseline information generated in the last decade, allow original interpretations. The evidence of coexistence between blade and bifacial technologies during the Mid-Holocene constitutes the main contribution of this paper. [Copyright &y& Elsevier]

This paper deals with a morphotectonic characterization of the Mendoza piedmont located in the South edge of the Andean Precordillera (32° - 33° S) very close to Mendoza city where at least 800.000 people habits. Marked tectonic geomorphological expressions exist in this area associated with the Andean Orogenic active front showing historical earthquakes with magnitudes from 6.0 to 7.0. The main objective of this work is the understanding of current deformation on the study area by two indirect and complementary methods: analysis of classic morphometric parameter (H index), and calculation of deformation fields by DINSAR technique. Applying morphometric analysis of drainage basins of the Mendoza piedmont, heterogenetic hypsometric values (H) were found as probable response to different dynamic relations with base level of the fluvial drainage system. This segmentation on piedmont behaviour allows us to discriminate three different areas (Northern, Central, and Southern). On the basis of morphological criteria, the Southern area reveals a greater tectonic activity matching with a greater vertical deformation inferred by DINSAR technique. These findings improve the knowledge about regional seismic hazard allowing release where main deformation is currently being accumulated in the Andean active front. [ABSTRACT FROM AUTHOR]

Assessing the integrity and resolution of archaeological sites in sandy environments is a key issue for understanding site formation processes in hunter-gatherer's contexts. A case study from the lower course of the Colorado River, at the eastern Pampa-Patagonian transition (Argentina) is presented here. The studied area is characterized by a sand dune relief that is superimposed upon ancient fluvial and marine environments. The sites date to between c. 2000 and 250 14C yr BP (late Holocene) and they are mostly located in eolian contexts. The objective of this paper is to understand environmental dynamics and the site formation processes that operated in archaeological sites of the late Holocene through the integration of geoarchaeological and taphonomic information. The obtained results allowed the identification of site formation processes related to the different environmental settings (coast, ancient delta and inland). However, general patterns that relate some taphonomic effects as root action and weathering with landscape processes such as pedogenesis at an areal scale were also recognized. Despite the varied and highly dynamic environmental conditions of this arid-semiarid area, archaeological contexts with good degrees of resolution and integrity were recognized. [ABSTRACT FROM AUTHOR]

Abstract Over the last decade, we have conducted an actualistic taphonomic research program in the Humid Pampas of Argentina, in order to build a corpus of information about the taphonomic agents and processes characterizing this sub-region. In this paper, we present a summary of our results after ten years of actualistic taphonomic studies in the Pampas. Our program includes both naturalistic and experimental research. Some of the controlled experiments consist of studies with different-aged guanaco bones, including sub-aerial weathering in a controlled environment, and water transport with disarticulated bones. Other studies were conducted at a local zoo, where we offered different types of prey to native small-sized carnivores (canids, felids, mustelids, and mephitids). Our naturalistic observations include the development of taphonomic transects in different environments. Through this method, we were able to study different topics among which some of the more significant are the movement of bones by small-sized carnivores and the distribution of beached Magellanic penguin specimens along the coast. Particular studies included the analyses of the content of dens occupied by small carnivores, the effects of a grassland fire in a vertebrate assemblage, the modifications produced by a local rodent -vizcacha- in the landscape, and the damage generated by pumas in guanaco carcasses. After ten years of systematic research we contributed to identify the potential mixture between modern bones and the archaeological record in relation to the environment; to determine bone preservation biases according to the properties of the record; to recognize agents responsible of bone accumulation and alteration; and to establish diagnostic criteria in order to differentiate cultural from natural patterns. [ABSTRACT FROM AUTHOR]

Wild cereals have been harvested all over the world by hunter-gatherer with evidences as much in South America as in Australia, North America and Subsaharian Africa. In some places there are still used for human consumption. The goal of this paper is to document phytoliths in inflorescence axis, and in kernels/inflorescences/bracts of several native Argentinian wild grasses in order to get an archaeobotanical comparative referential for the analyses of residues from both food plant processing activities and consumption. We could observe typical phytolith morphotypes from specific anatomical parts of grasses, but non-taxon specific, as well as non-diagnostic phytolith morphotypes, but characteristic of the phytolith association of a certain taxa. They all allow us to get a more complete view of the phytolith production for each specific taxon. Results obtained by Morisita Test-Past Program-suggest a trend to the organization at the level of subfamilies for the phytoliths production in the 14 species studied. Species of the genus Aristida and Cynodon show an intra-generic consistency in the production of phytoliths morphotypes per organ, and tend to be grouped in cluster analysis. In some species as Cynodon dactylon , Bromus catharticus , Aristida adscensionis , Sorghastrum pellitum and Paspalum dilatatum it can be noted a similarity in the morphotype production as much in inflorescence axis as in kernels/inflorescences/bracts. A morphological continuum between similar morphotypes could be also established, by comparing series of shapes within fragments of silicified plant tissue. Finally, we consider phytolith production from potential useful plant parts for human consumption, in a way as their presence alone, or associated with starch grain analyses, as showed by a previous work, could be used for regional dietary reconstructions. Our results from inflorescence/kernel phytolith production give us good expectation to be able to identify them in archaeological contexts. [ABSTRACT FROM AUTHOR]

This paper presents a systematic analysis of the shellfish assemblages recovered from Heshkaia 35, an archaeological site located in the southern tip of South America. Possible arguments concerning to environmental variations and resource depression are considered in an attempt to explain taxa composition and shell size. Results are also discussed in light of expectations based on optimal foraging models and taking into account other factors beyond biological parameters. Shellfishing activities were focused on small mussels, with statistical significant changes in mean shell size along the archaeological sequence of the site. Current knowledge about past variations in sea surface temperature does not seem to explain changes in shell size. Gathering of small mussels appears to be the corollary of resource depression at a local scale. This interpretation reinforces arguments that foraging decisions would have derived from territorial packing on the southeastern coast of Tierra del Fuego during the Late Holocene. [ABSTRACT FROM AUTHOR]

This paper shows the preliminary results of the zooarchaeological analysis of Dupuy Rockshelter (La Toma, San Luis Province, Argentina). This rock shelter has evidence of Late Holocene (Last Millennium) human occupation dating from 340 ± 40 BP. Some species, including Lama guanicoe and Ozotoceros bezoarticus , were exploited and their bones were used as raw material to make instruments. The zooarchaeological analysis is complemented by geological and phytoarchaological evidence which indicates a humid environment during the Holocene and a mixed diet that included vegetables. [ABSTRACT FROM AUTHOR]

This paper presents the analysis of the ichtyoarchaeological record from Los Bananos site (Goya, Corrientes, Argentine). The aim of this study is to render a first evaluation to the role played by fish in subsistence during subsequent occupations of the site. The site is located in the alluvial plain of Middle Paraná River, beside Paraná Miní creek, and it has provided new information about pottery and lithic technology, subsistence, chronology ( 14 C), site formation processes, etc. Bones from Los Bananos have been divided into three assemblages (LB1, LB2 and LB3), according to associated cultural materials. The pre-Hispanic populations that occupied this area by the end of the Late Holocene based their subsistence in hunting, gathering and fishing. Also, the makers of a distinctive ceramic ware associated with LB1 assemblage (related to Goya-Malabrigo entity - lato sensu -), relied on small-scale horticulture. Preceding materials of the other sets (LB2 and LB3) do not present necessary characteristics for cultural association as shown in LB1. The assemblages will be discussed in sequence of their deposition; and compared with results from other related sites. The results of zooarchaeological and taphonomic analysis of the faunal remains suggest that fish was an important resource in LB1. While from LB3 analysis, we will see that fish constituted a complementary resource in the diet. Thus, we can infer that, the role of animals in the diet of the site's prehistoric inhabitants changed during the time deposits were laid. [ABSTRACT FROM AUTHOR]

This paper discusses provisioning strategies of lithic raw materials at Maripe Cave site (province of Santa Cruz, Argentina). The archaeological sequence represents different moments of human occupation at the cave and in the study area, which show different lithic technologies. The morpho-typological analysis of the lithic cores recovered contributes to our knowledge about the strategies related to procurement and provisioning of the lithic raw materials used for artifacts production. We identified different raw materials from the analyses of lithic cores and other artifacts from the site. This allowed analyzing trends in selection and provisioning processes and interpreting the mobility strategies of the groups that inhabited the Deseado Massif since the Pleistocene–Holocene transition. Trends suggest that, during the Pleistocene–Holocene transition and early Holocene, abandoned cores from Maripe Cave mainly indicate people provisioning strategies. During middle Holocene, the cores shows blades extractions and raw material use from long distance, discarded with remaining potential utility. Finally, at late Holocene the cores were mainly prepared for blade extractions. Our results do not fully agree with Kuhn's proposal, probably due to both the theoretical polarization between the provisioning strategies and the palimpsest effect. [ABSTRACT FROM AUTHOR]

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]

A large (>0.1 km 2 ) and complex mass movement in the Central Andes of Argentina (final portion of Cordillera de Olivares, Frontal Cordillera), was studied to identify the triggering factors and understand their relationship with geomorphic, cryogenic and climatic dynamics. This debris-rockslide is composed of clast supported blocks of Permian–Triassic volcanic breccias. In order to characterize this feature, high resolution satellite imagery interpretation was carried out, together with the study of the landslide detachment zones and landslide bodies. These debris-rockslide events could have originated as a consequence of the combination of internal slow deformation and fragmentation under periglacial conditions, followed by a sudden collapse of the rock mass. Pre- and post-slide digital elevation models (DEMs) were created from topographical data with the help of a Geographic Information System (GIS) tool. Approximately 14.89 M m 3 of rock and debris travelled nearly 2 km from an elevation of 5023 m–4325 m asl. Although usually the origin of such catastrophic movements is related to seismically active areas with earthquakes whose magnitude frequently exceed Ms 6, our hypothesis is that this debris-rockslide event has a climatic origin caused by large snow accumulations during winters and subsequent fast meltdown processes during spring, which would have facilitated the sliding. The paper outlines the important role that snowmelt can play in the genesis and evolution of rock displacements and the importance of meteorological data, seismic catalogues, historical aerial photography and satellite images in geomorphological back-analysis. [ABSTRACT FROM AUTHOR]

In this paper, results of archaeological studies conducted in the central San Jorge gulf sector (north coast of Santa Cruz Province, Patagonia, Argentina) are presented. A distributional approach was employed, and a systematic surface sampling in several landscape units were performed, registering all lithic artifacts and other variables that could influence the archaeological visibility. The landscape units identified in this sector were: high plateau, plateau flank, cañadón León, temporary lagoons, and coast. The artifactual assemblage recovered is presented, analyzed and discussed in relation to several archaeological expectations derived from the resource availability of the different landscape units. Results are discussed in relation to ways in which these landscape units could have been used by hunter–gatherer populations that inhabited this sector during Late Holocene, considering the differential availability of resources of importance to Patagonian human groups. In this sense, the archaeological expectations were contrasted, with higher densities near the coast and lower densities on inland landscape units. Among the first, the availability of alimentary resources (mainly shellfish, fish and pinniped) would have produced longer residential settlement. Among inland landscape units, some differences were observed, which were related to variation in resources availability, such as fresh water sources and lithic raw materials. In this latter, more variability than anticipated according to the archaeological expectations was detected. [ABSTRACT FROM AUTHOR]

This paper describes results obtained through fatty acids analysis on a sample of lithic artifacts. Analyzed tools come mainly from the excavated assemblage of Cerro El Sombrero Cima (Tandilia, Argentina), where the occupation has been assigned to the Pleistocene/Holocene transition. They include fishtail projectile points (FTPP), retouched tools, and ground tools. A variety of resources have been identified which indicate the great diversity of organic materials used and highlights the importance of plants in past daily life. Also, through this method marine resources have been identified, giving support to the proposition that different environments, including the sea coast, were familiar to early hunter-gatherers in the region. In addition, results are relevant to the discussion of the hafting and recycling of FTPP and the generalized use of other tool types. [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]

This paper compiles a database of radiocarbon dates of archaeological sites that are currently available for the Pampean region. Based on the probability distribution of radiocarbon dates from this database, major temporal trends are defined, taphonomic and scientific biases are evaluated, and their implications for demography are suggested. Results indicate a continuous archaeological signal between ca. 14,500 and 100 cal BP. During the final Late Pleistocene and the Early Holocene, the archaeological signal is low in ca. 14,500–12,800 cal BP, and increases to a moderate and continuous signal in ca. 12,800–7500 cal BP. The archaeological signal for the former lapse correspond to the early peopling of the region and is related to the inhabiting and exploitation of key landforms (e.g., rock shelters, river valleys) and critical resources (e.g., lithic raw material, water). The low amount of available dates for the Middle Holocene (ca. 7400–3700 cal BP), and the associated archaeological signal would be due to the combination of various factors such as taphonomic biases, organization of prehistoric populations, and even a possible low population density. The obtained low but continuous signal for this period are discussed in the framework of the proposed models for the human occupation of the region suggesting that a hypothesis about population extinctions and disruptions processes could not be sustained. Finally, during the Late Holocene (from 3700 to 100 cal BP) human occupations are recorded in all the micro-regions. Regardless of biases, this signal is interpreted as an increase in demographic density at a regional level. [ABSTRACT FROM AUTHOR]

The distribution of late Pleistocene to Holocene rockslides in the western flank of the eastern mountain ranges of Central Precordillera (30° 40′–31° S), has been analyzed to determine the triggering mechanisms. The mode of failure was determined to be translational sliding. This paper presents the results of research on one of the Holocene rockslides located in the western flank of Sierra de La Dehesa, which is composed of stratified limestones of early Paleozoic age. In order to characterize this slide, high resolution satellite imagery interpretation was carried out, along with the recognition of the landslide detachment zones and landslide bodies with the aim of reconstructing the pre-slide topography. The model proposed for this slide is a translational or planar slide, as the mode of failure was along a broadly planar surface accompanied by shear or tensile fractures and joints. The estimated rock volume involved is 1.24 Mm 3 . We compared rockslide occurrence patterns to slope, topography, lithology, geological structures, and seismicity records. After analysis of the spatial relationships among all the slides and the distribution of seismic epicenters, historical earthquakes and neighboring Quaternary faults as seismogenic sources, we hypothesize that these Quaternary rockslides in the Central Precordillera have been triggered by shallow seismicity associated with active faults. [ABSTRACT FROM AUTHOR]

Abstract: This paper summarizes the results of the research carried out during a decade at the Hornillos 2 rockshelter, located at 4020 m asl in the Dry Puna of Argentina. The human occupations in this site are bracketed between the Pleistocene–Holocene boundary and the mid-Holocene, challenging the idea of a widespread abandonment of the Andes highlands during mid-Holocene due to extreme arid conditions (i.e. the “silencio arqueológico” or archaeological silence hypothesis). Nine occupational levels have been recognized in the timed span at the site, the result of hunter–gatherer activities carried out in a highly oscillating and changing environment. Here we present the mean trends and patterns observed in the full set of lines of inquiry applied in the site: lithic evidence, zooarchaeological analysis, rock art, stratigraphic and spatial analysis, and isotopic data. The outcomes of these studies, together with the site location features, known raw materials sources and regional archaeological evidence, indicate that hunter–gatherer groups reduced their residential mobility, and increased the intensity of their occupations and the rate of technological innovations in the arid and unstable mid-Holocene landscapes. [Copyright &y& Elsevier]

Abstract: This paper reports the compilation and initial analysis of a database of 14C dates from archaeological sites in Argentina for the period 13,000 and 7000 14C BP. The spatial and temporal distribution of human occupation evidence during this period is surveyed, with discussion of potential sampling biases affecting the recognition of such sites in each region of Argentina. The archaeological signal of human occupation at the beginning of this period (13,000–11,000 14C BP) is suggestive but sparse, and weak. However, from about 11,000 14C BP there is a consistent archaeological signal. Most of the earliest occupation evidence comes from the eastern Pampas and from southern Patagonia. In the Chaco and Northeast regions, similarly early archaeological sites have not yet been detected. This contrast may reflect the actual distribution of early human occupation, but it may also reflect biased research effort and/or systemic factors affecting the visibility and level of preservation of the early archaeological record. In other regions such as the eastern slope of the Andes in Patagonia, the peri-Andean Central West, and the Northwest, where there has been intensive archaeological research for an extended period and there are fewer systematic factors which are likely to bias archaeological visibility, the absence of archaeological evidence of early occupation may indicate delayed colonization of these more marginal environments. The conclusion discusses the implications of 14C dates associated with Fishtail Projectile Points for the western hemisphere pre-Clovis debate, and the implications of terminal Pleistocene/early Holocene dated remains of extinct mammals for the megafaunal overkill hypothesis. [Copyright &y& Elsevier]

Abstract: During the late Holocene, the coastal marine resources of southern South America were exploited by both marine hunter-gatherers with aquatic mobility in the Beagle Channel and the Chilean archipelago and terrestrial hunter-gatherers who inhabited various coastal settings in Argentina. Although the two cultures differed in technology and in historical exploitation patterns, they both used otariids, molluscs, fishes and sea birds as sources of food and raw materials for centuries. Ultimately, their use of these resources, particularly of otariids, declined strongly at different times. Overexploitation has been suggested as the main reason for this pattern, at least in the Beagle Channel, but similar declines in the north Pacific have been attributed to an increase in sea surface temperature (SST). The present paper tests the latter hypothesis in southern South America by using the δ18O of bivalve shells (Aulacomya atra atra and Mytilus edulis) collected at archaeological sites as a proxy for SST and comparing the patterns of δ18O with the patterns of resource exploitation by hunter-gatherers. Samples were collected from the Beagle Channel and the central-northern Patagonian coast (north to 43° S) to generate two comparable datasets. The results suggest that SST increased in both areas at the beginning of the late Holocene and was slightly higher than at present during most of that period, except during the Little Ice Age, when values similar to those recorded at the end of the middle Holocene were found. The relative importance of otariids, mainly Arctocephalus australis, in the economy of the inhabitants of the Beagle Channel declined as SST increased, but otariid exploitation did not intensify again during the Little Ice Age. On the contrary, the intensity of otariid exploitation in central-northern Patagonia, mainly Otaria flavescens, was unrelated to the changes in δ18O. Thus, changes in SST are unlikely to be the major driver of these resource-exploitation patterns. [Copyright &y& Elsevier]

Abstract: Paso Otero archaeological locality (Pampean region, Argentina) has provided detailed paleoenvironmental reconstructions and faunal assemblages from the Pleistocene/Holocene transition and Early Holocene. This time span is represented by Paso Otero 5 (c. 10 450–10 200 14C BP; 12 593–11 353 cal. BP) and Paso Otero 4 (c. 9900–7700 14C BP; 10 667–7982 cal. BP). Palaeoenvironmental studies have been carried out on the basis of data derived from geoarchaeological, sedimentary, palynofacies, pollen, diatoms and silica microremains. Unlike other areas of the Pampean region, bone assemblages from Paso Otero include high representation and diversity of taxa. In this paper, paleoenvironmental reconstructions and faunal assemblages from both sites are integrated in order to discuss the consistency of the inferences derived from the two lines of evidence, its contribution to the paleoecological scenarios, and to faunal extinctions. It is suggested that not only hunting pressure but the mere presence of humans was a factor in ecosystem disturbance and is the most parsimonious explanation for the process of extinction. [Copyright &y& Elsevier]

Abstract: The Tandilia range is a discontinuous series of hills and valleys located at the central area of the Pampean region (Argentina). The process of human settlement reached in this zone the highest population densities and reoccupation levels of Southern South America, developing under the strongly changing climatic conditions that characterized the Pleistocene–Holocene transition. This paper analyzes the geoarchaeological and paleoenvironmental record of the Pleistocene–Holocene transition (c. 9400–10,500 14C BP) recovered from cave and rockshelter sedimentary successions of the Tandilia range. The analysis of several lines of evidence (stratigraphic, geoarchaeological, archaeological, zooarchaeological, and paleobotanical), suggests that a cold arid to semi-arid climate characterized the late Pleistocene (c. 10,500 BP), and changed abruptly to warmer conditions towards the beginning of the Post-Glacial Period. As a consequence of this climatic amelioration, the populations inhabiting the Tandilia range would have been benefited by a higher availability of resources, which could explain the higher levels of site density and reoccupation found in the area during this period. [Copyright &y& Elsevier]

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: The ethnohistorical and archaeological bibliography on mortuary practices of the indigenous societies of Pampa and Patagonia refers extensively to the use of the envelope of bodies, for different purposes. One has been to facilitate the transport of the deceased until their final place of burial. This practice has been registered on the Chenque I site, a hunters- and-gatherers cemetery located in the Parque Nacional Lihué Calel, La Pampa, Argentina, used during the last part of late Holocene. It was applied both for primary as to secondary burials, being single and multiple. Some burials surrounded by a whitish doughy substance, where shell beads are imbricated, were recovered during the excavations carried out in various areas of the site. The purpose of this paper is to communicate the results of the verification methods applied to the aforementioned substance to corroborate that it is the product of the taphonomic degradation of leather. These methods allowed an approach to the identification of the species employed, possibly Rheidae. Secondly, the state of preservation of enveloped burials was compared with others without it, in order to inquire whether this mortuary practice had an effective role in protecting the human remains. [Copyright &y& Elsevier]

Abstract: The Middle Holocene is a particular time period in which there are uneven environmental dynamics all along the southern portion of the continent. Whereas in the Puna, extreme aridity and high temperatures (the so-called “Hypsithermal” period) have been recorded, a more humid and rainy phase dominated southern Tierra del Fuego. The present paper explores the palaeoenvironmental situation of Isla de los Estados (Staaten Island, 54°38′–54°55′ S; 63°48′–64°46′ W) and its relationship with the archaeological record left behind by ancient canoeing people. The considered period is characterized by exceptionally windy conditions. The palaeoenvironmental information could be used as an explanation for the absence of cultural remains and also for the scarce archaeological record for Península Mitre. At the beginning of the Middle Holocene, the diatom record shows a large amount of Aulacoseira sp that could indicate either windy conditions or higher water levels at the site core. The more distinctive changes in the diatom assemblages occurred at ca. 5000 cal B.P., suggesting a shallower water level and more acidic conditions. By 3000 cal B.P., the diatom species are strongly linked to peat and swampy environments. However, during the late Holocene, milder conditions might have favored seasonal travelling to the outer islands of the Fuegian Archipelago, though no definitive or permanent settlements have been found. [Copyright &y& Elsevier]

Abstract: The aim of this paper is to discuss hunter-gatherer settlements on coastal sand dunes in the Southwest of Buenos Aires Province (Argentina). Technological, archaeofaunal and radiocarbon information from Barrio Las Dunas site is presented, and compared with the context of other Pampean coastal sites. Barrio Las Dunas site is located on a sand dune and shows a hunter-gatherers settlement from 6900 14C BP. The archaeofaunal context demonstrates the exploitation of marine taxa: mammals (Otariidae) and fish (Pogonias cromis). Lithic tools such as end scrapers, side scrapers, denticulates, notches and many retouched flake tools were identified. Also, some carefully worked unifacial and bifacial tools were recovered. Artifacts were mainly manufactured from basalt, followed by quartzite and subarkose. The data presented supports some palaeoenvironmental considerations: first that the southwest Atlantic coast sand dunes of Buenos Aires province date from the Early-Middle Holocene and second, that Barrio Las Dunas site was next to a coastal lagoon or estuarine palaeoenvironment with a crab community. This context was appropriate for black drum feeding. Early-Middle Holocene sites from the area illustrate the variability of coastal environments when different landforms, which included lagoons, marsh, sand dunes and beaches, were present in the landscape. The sand dunes were used by hunter-gatherers in their periodic activities; e.g., lithic artifacts were manufactured and sea lions and black drums were butchered and eaten. This data in addition to the areal information show a complex use of the coast during this period. [Copyright &y& Elsevier]

Abstract: This paper analyzes the spatial organization of two layers corresponding to the first half of the Middle Holocene from the Hornillos 2 rockshelter (Susques, Jujuy Province). Some important issues taken into account are the good preservation of the site and the sedimentary deposition processes which coincide with paleoclimate aspects. Correlation of different archaeological lines of evidence allows interpretation of the connection between several activity areas and their occupational intensity. There is a trash heap related to a short occupation period at the beginning of the Middle Holocene and a main zone of intense activity ca. 6200 yrs BP. These facts are in accordance with the archaeological expectations proposed for certain periods of the Middle Holocene. [Copyright &y& Elsevier]

Abstract: The Carrizal river basin is located to the northwest of San Juan Province in the Iglesia department. One of the main geological hazards that affect the Iglesia department is flash floods, produced by heavy seasonal rains, characterized by their high velocities and destructive power. The Carrizal river basin was selected as a test case to evaluate the potential magnitude of flash floods in relation to their associated hazard level. This paper evaluates some of the hydrological aspects of a torrential regime of Carrizal basin that can cause severe damage like the event that took place in the area during February 1944. Various morphometric characteristics of the Carrizal river basin were analysed in order to evaluate its flash flood hazard. For this purpose, the basin was divided into five sub-basins, according to lithological aspects, and some basic measurements (surface, perimeter, basin length, river beds, elevations and slope of the main river bed, and of a number of minor river beds) were calculated. These measurements allowed predicting approximately the behaviour of the basin in the presence of a series of theoretical rainstorms that may generate unusual runoff volumes. The predicted flash floods were compared against the Carrizal flash flood. [Copyright &y& Elsevier]

Abstract: This paper deals with the way in which the environmental dynamics that took place in the lower basin of the Colorado River (Buenos Aires province, Argentina) have affected the degree of archaeological resolution, integrity, and site preservation in different sectors of the study area (e.g., coastal fringe, delta and interior dune fields). Evidence from geomorphologic, stratigraphic, and sedimentary analyses as well as chemical parameters and zooarchaeological assemblages are used in order to propose spatial and temporal variations in the structure of the archaeological record. These lines of evidence were also used for inferring general paleoclimatic trends. The results obtained indicate that the inland landforms that contained Initial Late Holocene archaeological assemblages (3000–1000 14C BP) have suffered important morphodynamic processes that produced site destruction, loss of organic material and lower degrees of integrity and site resolution. Conversely, landforms located near the delta and the coastal fringe underwent more stable geomorphic processes (e.g., pedogenesis) that promoted better preservation, resolution, and integrity during the Initial Late Holocene and, particularly, during the Final Late Holocene (1000–250 14C BP). The recognition of this pattern is crucial in order to evaluate demographic processes linked with the intensity and mode of hunter-gatherer occupation of the area and population dynamics throughout time. [Copyright &y& Elsevier]

Abstract: Geological studies are fundamental to archaeologists as they provide essential data to understand certain processes involved in the present archaeological record. When working on marine coastal archaeology, the information provided by geomorphologic studies with regards to the evolution and dynamics of coastal marine lines is essential to assess the availability and accessibility of certain marine coastal areas, and their resources, to human populations of the past. This is also the key to reach correct cultural interpretations. However, on certain occasions, archaeological information can also offer valuable alternative data for geologists to reach geological interpretations, for instance when working on the evolution and changes of coastal sea lines. In this case, spatial and temporal scales must be regarded. This idea is supported on the experience gained through research done on the Patagonian Atlantic coast at the two archaeological localities introduced in this paper: Cabo Blanco, where we evaluate models of evolution of the coastline with a number of radiocarbon dates from excavated sites; and Punta Medanosa, where we discuss the temporal depth of the formation of the coastal ridges for the mid-Holocene transgression. [Copyright &y& Elsevier]

Abstract: This paper presents the results of a taphonomic and paleoenvironmental analysis of small mammal remains recovered from the Negro Muerto and Angostura 1 archaeological sites. These sites (ca. 0.5 and 0.95 ka BP, respectively), are located in the middle and lower Negro River valley in northern Patagonia, Argentina. Based upon the presence of several types of evidence (cut marks, bone tools, and thermal alteration), it is proposed that Holochilus brasiliensis and cavies were acumulated by humans. At the Angostura 1 site, some remains also show evidence of having been generated by carnivores (digestion, breakage patterns, and relative skeletal element abundances). This indicates that carnivores (e.g., Puma concolor) could have contributed to the formation of the small mammal assemblages. Other small mammal species recovered at both sites (e.g., Galea leucoblephara, Microcavia australis, Akodon molinae, and Graomys griseoflavus) suggest semi-desert environmental conditions, similar to those found today. The presence of Reithrodon auritus and Oligoryzomys sp. indicate the development of open herbaceous steppe environments in proximity to bodies of water. However, the discovery of H. brasiliensis at both sites, an orizomyine of amphibious habitats and subtropical origin, and which is now absent in the area, suggests warmer and wetter conditions during this period. [Copyright &y& Elsevier]

Abstract: The recently excavated Paso Otero 4 site is located within the Paso Otero archaeological locality (Necochea District, Pampean Region). The site is characterized by the presence of a great variety of archaeological materials and a rich and complex stratigraphic record which allows use of an interdisciplinary approach. The objective of this paper is to present the results of the geoarchaeological, palynological, phytolith, and diatom analyses in order to reconstruct the paleoenvironmental conditions for the final Late Pleistocene through Holocene. These lines of research allow inference of paleoenvironmental and palaeoclimatic conditions on both local and regional scales. At the site, the Río Salado Member (Unit 2), where the archaeological deposit is buried, underwent sudden and fluctuating changes in water availability conditions, although the setting was basically characterized by calm depositional processes within and along the margins of interconnected lagoons. Paleoclimatic reconstructions indicate the existence of abrupt climatic changes throughout the sequence. Early Holocene human occupations took place under regionally temperate-warm climates while the end of the Middle Holocene witnessed cold and arid or cold temperate climates. In general terms, paleoenvironmental conditions inferred for Paso Otero 4 are in accordance with regional reconstructions proposed for the Pampas. [Copyright &y& Elsevier]

Abstract: This paper presents a synthesis of geological, geochemical, and archaeological information for the Huenul obsidian source located in northern Patagonia (Neuquén Province, Argentina). Important information recently published on other obsidian sources in the South-Central Andes of Argentina and Chile provide the context for this endeavor, allowing evaluation of the role of this lithic source within the network of human mobility and interaction on different spatial scales. It is suggested here that Huenul obsidian is genetically related with the Tilhué Formation, already been mapped in detail. This regional information provides a search model for geoarchaeological surveys. This raw material displays a remarkable supra-regional distribution in the archaeological record, although it is regionally under-represented. Three alternative hypotheses explaining the distribution of Huenul obsidians allow evaluation of technological decisions, marginal vs. nuclear role of certain spaces for past human societies, and territorial organization. [Copyright &y& Elsevier]

Abstract: Mineral colorants are frequent in the Holocene archaeological record of the Southeastern Pampean region, but they have been often unexplored. This paper presents the results of macroscopic analysis, and thin section and X-Ray diffraction techniques applied to mineral pigments from the Calera site and the Zanjón Seco and Nutria Mansa archaeological localities. The use of both analytical techniques as complementary tools is a contribution to pigment provisioning studies and the general discussion of mineral raw material exploitation in the region. In prehispanic times, pigments were obtained from mineral sources available in the Tandilia System and, in smaller proportion, from the Ventania System. Transporting these coloring raw materials to the studied archaeological contexts implied different provisioning efforts through local, middle and long distances, and their procurement was related to local and regional mobility circuits of Pampean prehispanic hunter-gatherers. [Copyright &y& Elsevier]

Abstract: This paper discusses the ongoing ethnoarchaeological research carried out in Yamana shell middens of Tierra del Fuego. Ethnoarchaeology is used in this research as a tool to improve the archaeological methodology by testing it against anthropological, ethnographical and ethnological sources for achieving more accurate reconstructions of past societies. The ethnographical/ethnological information also is coupled with an experimental approach devised to understand physical and social processes, such as site formation processes and resource use and management. Specifically, this experimental approach was applied to the archaeological sites Túnel VII and Lanashuaia I (Tierra del Fuego, Argentina). [Copyright &y& Elsevier]

Abstract: One of the main geological hazards that affect the Iglesia department is flash floods, produced by heavy seasonal rains, characterized by their high velocities and destructive power. These streams are generated in the watersheds of the mountainous region of the Cordillera Frontal. The del Molle basin was selected as a suitable case to evaluate the potential magnitude of flash floods in relation to their associated hazard level in Malimán de Arriba, located directly at the confluence of the tributaries with the Blanco River. This paper evaluates some of the hydrological aspects of a torrential regime basin that caused severe damage in Malimán during January 2010. This work analyzes different morphometric characteristics of the El Molle basin in order to evaluate the flash flood hazard. For this purpose, the basin is divided into four sub-basins and some basic parameters (surface, perimeter, basin length, elevations and slope of the main riverbed) are calculated. These parameters allow approximate prediction of the behavior of the basin in the presence of a series of theoretical rainstorms which may generate unusual runoff volumes. The predicted flash floods were compared against the Malimán flash flood. [Copyright &y& Elsevier]

Abstract: Exhumed organic megastructures are analyzed in this paper. Large paleocaves (0.7–2.1m width and 0.7–1.5m height) are related to the digging of Xenarthra (Mammalia) that lived in the Pampas during the Pleistocene. Some of these burrows are completely filled by sediment, and others are found partially empty. They occur within the city of Mar del Plata and its surroundings, mostly restricted to the Miramar Formation. Three types of galleries have been identified. The larger caves (type I) are related to the digging activity of mylodontids (e.g. Glossotherium). Type II caves are related to smaller mylodontids (Scelidotherim leptocephalus). Other caves of similar size are attributed to the dasypodid Pampatherium (type III). The number of digits recognized in scratch marks on the cave walls helped to distinguish between mylodontid and dasypodid activities. The abundance of these caves has been interpreted in relation to water availability in the surroundings of the Tandilia Range, flooding potential, and shelter to avoid predation by carnivores. The paleobiologic and paleoecological significance of the structures assigned to ants or termites, and cave reoccupation by specimens of Arctotherium latidens (Ursidae, Tremarctinae), are also discussed. [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]

Abstract: The main goal of this paper is to highlight regional and temporal variation in the presence and exploitation of faunal resources during the Late Pleistocene and Early Holocene (ca. 12000–7000 uncalibrated 14CyrBP) in the Pampean region (Argentina, South America). The main issues discussed are a summary of archeological and zooarchaeological evidence (sites, location, chronology, lithic technology, faunal distribution and diversity, etc.) both on regional and areal scales. The topics included in order to characterize subsistence strategies are the climatic changes that operated on and influenced the species, differential species extinction and survival, exploited species diversity, procurement and processing techniques, and intensity of faunal exploitation. It is proposed that the Late Pleistocene–Early Holocene period is characterized by a generalized regional economy, as has also been recently proposed for North America. In general terms, a broad spectrum of resources would have been exploited by humans as suggested by the presence and diversity of consumed species. Given the fluctuating climatic conditions during the Pleistocene-Holocene transition, a subsistence pattern composed of a broad diet would have been a suitable strategy to promote in unstable environments. Both taxonomic diversity and richness are greater when compared with the following time period (Middle Holocene), characterized by a specialized regional economy. [Copyright &y& Elsevier]

Abstract: One of the most noticeable, intense and long-lasting human adaptive explorations that occurred in the mid-Holocene was the specialisation in the exploitation of coastal resources that happened in the South of Chile and Argentina. There, the continental border is abrupt and jagged, rainy and covered by woods. In the mid-Holocene, and apparently quite suddenly, an intensification of the human use of littoral resources was developed, which differed considerably from what happened in the rest of Patagonia and Tierra del Fuego. This paper examines in particular the role of the peculiar environment of the area: its importance as a selective factor is evident, but it is not possible to identify within it the factor which determined the starting of the adaptation process. [Copyright &y& Elsevier]