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Monte Verde II in southern Chile is one of the most important, and debated, sites for understanding of the early peopling of the Americas. The authors present 43 radiocarbon measurements based on cores of sediments that overlie the archaeological deposits adjacent to the site. Statistical analysis of these dates narrows the deposition of the earliest sediments sealing the occupational layer to c. 14 550 cal BP. The consistency between the dates of the site's archaeological strata and its adjacent deposits allows not only consolidation of the site's chronology, but also illustration of how a multi-pronged approach can inform debates surrounding the peopling of new lands—in the Americas or elsewhere.

Se describen e ilustran nuevos hallazgos de restos fósiles de uno de los escarabajos estercoleros de Pilauco, Onthophagus pilauco Tello, Verdú, Rossini y Zunino, 2021 (Coleoptera: Scarabaeidae), extinto en la base de la cronozona Younger Dryas, al fin del Pleistoceno (~12.800 años antes del presente) en la Patagonia norte de Chile. Análisis recientes de material procedente del sitio Pilauco permitieron registrar nuevos restos fósiles pertenecientes a O. pilauco, incluidos restos de clípeos con un cuerno central excepcional que asignamos a especímenes machos. Los nuevos descubrimientos nos permitieron revisar la descripción propuesta anteriormente por los descriptores y atribuir el sexo hembra al holotipo de O. pilauco. A la luz de los conocimientos actuales sobre el género, se discute la singularidad de este carácter fenotípico (i.e., cuerno del disco del clípeo) dentro de los Onthophagus americanos y la posible relación con grupos de la región asiática. A partir de esto, sugerimos que las novedades morfológicas observadas en O. pilauco, corresponden a rasgos únicos entre los Onthophagus americanos, que posiblemente se originaron a partir del aislamiento durante la última glaciación en la Patagonia norte de Chile.

The debate on the primary cross-curricular skills or fundamental competencies that must be improved in higher education has increased in the last few years. This is especially important in the new distant learning environments, which bring new challenges to the educational process. Econometric models have been designed to explain the students’ academic performance, which has been measured using their qualifications average, the number of failed subjects, passed subjects, and withdrawn subjects, and the level of progress, among other indicators, to try to understand the influence of variables such as students’ self-esteem, reading comprehension, English proficiency level, and performance in a mathematics-related subject on the students of accountant auditor program from Pontificia Universidad Católica de Valparaiso. Students were asked to fill in a questionnaire to collect data on the psychological and pedagogical variables, while the socio-economic and socio-demographic data were collected from the university. The results have shown that the most significant variables in the development level of this skill type are socio-demographic and socio-economic characteristics. Some of the psychological and pedagogical variables that have, to a lesser degree, some influences are self-regulation in the learning process and the self-perception of anxiety levels. Lastly, some recommendations to intervene in the students’ learning process are presented with the objective of achieving a higher level of development in this type of competences.

Remobilization and deformation of surficial subaqueous slope sediments create turbidites and soft sediment deformation structures, which are common features in many depositional records. Palaeoseismic studies have used seismically‐induced turbidites and soft sediment deformation structures preserved in sedimentary sequences to reconstruct recurrence patterns and – in some cases – allow quantifying rupture location and magnitude of past earthquakes. However, current understanding of earthquake‐triggered remobilization and deformation lacks studies targeting where these processes take place, the subaqueous slope and involving direct comparison of sedimentary fingerprint with well‐documented historical earthquakes. This study investigates the sedimentary imprint of six megathrust earthquakes with varying rupture characteristics in 17 slope sediment cores from two Chilean lakes, Riñihue and Calafquén, and evaluates how it links to seismic intensity, peak ground acceleration, bracketed duration and slope angle. Centimetre‐scale stratigraphic gaps ranging from ca 1 to 20 cm – caused by remobilization of surficial slope sediment – were identified using high‐resolution multi‐proxy core correlation of slope to basin cores, and six types of soft sediment deformation structures ranging from ca 1 to 25 cm thickness using high‐resolution three‐dimensional X‐ray computed tomography data. Stratigraphic gaps occur on slope angles of ≥2.3°, whereas deformation already occurs from slope angle 0.2°. The thickness of both stratigraphic gaps and soft sediment deformation structures increases with slope angle, suggesting that increased gravitational shear stress promotes both surficial remobilization and deformation. Seismic shaking is the dominant trigger for surficial remobilization and deformation at the studied lakes. Total remobilization depth correlates best with bracketed duration and is highest in both lakes for the strongest earthquakes (M w ca 9.5). In lake Riñihue, soft sediment deformation structure thickness and type correlate best with peak ground acceleration providing the first field‐based evidence of progressive soft sediment deformation structure development with increasing peak ground acceleration for soft sediment deformation structures caused by Kelvin‐Helmholtz instability. The authors propose that long duration and low frequency content of seismic shaking favours surficial remobilization, whereas ground motion amplitude controls Kelvin‐Helmholtz instability‐related soft sediment deformation structure development.

The effects of a sudden rainfall (40 mm d−1) event on the surface waters covering muddy tidal flats were studied during April 2016 at the estuarine Cruces River wetland in south-central Chile (∼40°S). The study area included flooded vestigial tree trunks, which is evidence of coseismic subsidence associated with the 1960 Valdivia earthquake as a source of environmental variability. The tidal flat with vestigial tree trunks registered the fastest and highest depth of inundation. In contrast, the tidal currents velocity and total suspended solids’ concentrations were higher at the flat without trunks. Sudden rainfall events can significantly modify the characteristics of surface waters above sedimentary intertidal surfaces, where structures such as flooded trunks are present.

In-situ soft sediment deformation structures (SSDS) are commonly used as paleoseismic indicators in marine and lacustrine sedimentary records. Earthquake-related shear can deform sediment in the shallow subsurface through Kelvin-Helmholtz instability. The SSDS related to Kelvin-Helmholtz instability have been used to quan-tify shaking strength of past earthquakes. However, the relative importance of i) lithology and physical proper-ties, ii) potential basal shear surfaces (e.g. clastic deposits), iii) slope angle, and iv) seismic shaking strength (e.g. peak ground acceleration) for deformation related to Kelvin-Helmholtz instability remains poorly studied. Lake Rinihue (south-central Chile) is chosen as a natural laboratory for disentangling the effect of the aforemen-tioned factors because i) the sediment composition of background sediment varies downcore and ii) volcanogenic clastic deposits are abundant within the sedimentary sequence. A previous study at lake Rinihue identified 25 SSDS intervals induced by historical earthquakes of varying rupture extent in 17 sediment cores taken at slope angles ranging from-0.2 degrees to-4.9 degrees (i.e. 16 slope sites and 1 basin site). Our study shows that defor-mation mostly occurs directly above volcanogenic deposits (i.e. 72 % of SSDS intervals), suggesting that volcanogenic deposits promote earthquake-induced deformation by strain softening, liquefaction or water film formation. Deformation thickness of SSDS increases with higher slope angles (i.e. strong positive correlation). Ad-ditionally, deformation thickness commonly corresponds to the stratigraphic depth of the youngest preceding volcanogenic deposit, but for steeper slope angles stratigraphically older volcanogenic deposits can function as basal shear surface. Therefore, we suggest that deformation thickness is primarily regulated by gravitational stress (i.e. slope angle) and secondarily by the stratigraphic depth of volcanogenic deposits. The earthquakes related to strongest shaking caused almost exclusively SSDS with highest deformation degrees (i.e. folds and intraclast breccia) as well as largest spatial extent of SSDS, resulting in highest numbers of related SSDS in the investigated cores. Thinner SSDS have higher deformation degrees at a given shaking strength, as seismically -induced shear energy acts more effectively on thinner deforming sequences. Therefore, we suggest that deforma-tion degree is primarily controlled by shaking strength and secondarily modulated by the thickness of the deforming sequences. We infer that deformation thickness is not a reliable indicator of paleoseismic shaking strength as this relies on many preconditioning factors independent of shaking strength. On the other hand, deformation degree can be a good proxy for shaking strength also in settings with varying lithotypes and intercalated clastic event deposits, provided multiple cores are studied to avoid under-or overestimation of paleoseismic shaking strength. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

Autogenic processes, such as sudden avulsions, unexpected channel migrations and backfilling phenomena, can considerably alter the propagation of sediment-laden flows on alluvial fans. Once the initial and boundary conditions of the hazard scenario with a given return period are determined, the delineation of the associated exposed areas is based on one numerical, essentially deterministic, process simulation, which may not adequately reflect the underlying process variability. By following a ‘similarity-of-process concept’ we generated sediment-laden flows on an experimental alluvial fan. Thereby, we considered an alluvial fan model layout with a curved guiding channel and featuring a convex shape. As loading conditions, we defined a reference, an increased and a reduced level for the released water volume and the predisposed solid fraction. Further, we imposed two different stream power regimes and executed, for each factor combination, eight experimental runs. The associated exposure areas were recorded by video and were mapped in a GIS. We then analyzed exposure data and derived exposure probability maps superposing the footprints of the eight repetitions generated by each experimental loading condition. The patterns of exposure associated with specific loading conditions showed a noticeable variability due to the main effect of the total event volume, the solid fraction and the interactions between them and with the imposed stream power in the feeding channel. Our research highlights that a probabilistic notion of exposure in risk assessment and mitigation needs to be considered. Further, a major challenge consists in adapting numerical codes to better mirror the stochastics of process propagation for more reliable flood hazard and risk assessments.

The Younger Dryas (YD) impact hypothesis posits that fragments of a large, disintegrating asteroid/comet struck North America, South America, Europe, and western Asia ~12,800 years ago. Multiple airbursts/impacts produced the YD boundary layer (YDB), depositing peak concentrations of platinum, high-temperature spherules, meltglass, and nanodiamonds, forming an isochronous datum at >50 sites across ~50 million km² of Earth’s surface. This proposed event triggered extensive biomass burning, brief impact winter, YD climate change, and contributed to extinctions of late Pleistocene megafauna. In the most extensive investigation south of the equator, we report on a ~12,800-year-old sequence at Pilauco, Chile (~40°S), that exhibits peak YD boundary concentrations of platinum, gold, high-temperature iron- and chromium-rich spherules, and native iron particles rarely found in nature. A major peak in charcoal abundance marks an intense biomass-burning episode, synchronous with dramatic changes in vegetation, including a high-disturbance regime, seasonality in precipitation, and warmer conditions. This is anti-phased with northern-hemispheric cooling at the YD onset, whose rapidity suggests atmospheric linkage. The sudden disappearance of megafaunal remains and dung fungi in the YDB layer at Pilauco correlates with megafaunal extinctions across the Americas. The Pilauco record appears consistent with YDB impact evidence found at sites on four continents.

Subaqueous landslides are common features at active and passive ocean margins, in fjords and lakes. They can develop on very gentle slope gradients (

Current archaeological paradigm proposes that the first peopling of the Americas does not exceed the Last Glacial Maximum period. In this context, the acceptance of the anthropogenic character of the earliest stone artefacts generally rests on the presence of projectile points considered no more as typocentric but as typognomonic, since it allows, by itself, to certify the human character of the other associated artefacts. In other words, without this presence, nothing is certain. Archaeological research at Piauí (Brazil) attests to a Pleistocene human presence between 41 and 14 cal kyr BP, without any record of lithic projectile points. Here, we report the discovery and interpretation of an unusual stone artefact in the Vale da Pedra Furada site, in a context dating back to 24 cal kyr BP. The knapping stigmata and macroscopic use-wear traces reveal a conception centred on the configuration of double bevels and the production in the same specimen of at least two successive artefacts with probably different functions. This piece unambiguously presents an anthropic character and reveals a technical novelty during the Pleistocene occupation of South America., Funding was provided by the French Ministry of Europe and Foreign Affairs. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

In CE 1960, Lake Cucao on Chiloé Island in south central Chile was inundated by the tsunami of the Great Chilean Earthquake (Mw 9.5). The area of what is now the lake basin has been submerged since the end of the rapid postglacial sea-level rise and has recorded tsunami inundations in its sediment record since then. This study reconstructs the tsunami history of Lake Cucao. Reflection-seismic profiles and side scan sonar data of the lake reveal a tidal delta with a crosscutting channel, which controls the sedimentary environment in the coast-facing part of Lake Cucao. The convergent pattern of seismic reflections near this channel indicates that tidal currents were active in the lake at least episodically since the formation of a major unconformity with strong reflection amplitude, which records the onset of lacustrine sedimentation. A radiocarbon date at the base of one of the 21 collected sediment cores dates this reflector to ~3800 years BP. Little net vertical displacement (≤ 2 m) in combination with an outlet river channel that can act as a pathway for sediment transport appears to have maintained the sensitivity of Lake Cucao to record tsunami inundation. The sedimentary record contains 15 clastic layers which are interpreted as tsunami deposits. The confidence level on the tsunami interpretation depends on five site-specific criteria, which are: (i) high magnetic susceptibility of the sediment indicating high clastic content, (ii) cross core correlation indicating widespread deposition, (iii) acoustic reflector correlation to the sedimentary record (also indicating widespread deposition), (iv) presence of mud clasts, and (v) age correlation to known paleotsunamis in the area. In this way, eight clastic layers are interpreted as tsunami deposits with a high confidence level, five with a medium confidence level and two with a relatively low confidence level. This study adds a long paleotsunami record on a coastline where extreme tsunamis occur frequently and where long (>2000 years) paleotsunami records are still sparse.

A new assemblage of fossil beetles of Upper Pleistocene age, dated between 15,754 and 14,697 cal yr BP, is described and interpreted based on cluster analysis. In this study, we present an analysis on the taxonomic composition, and the paleoenvironmental implication of the fossil beetle assemblage in the archaeo- paleontological site of Pilauco in Osorno, south-central Chile (40°34′S-73°07′ W). Around 17,370 cal yr BP at the onset of deglaciation the old Damas River abandoned its alluvial plain; afterwards wetlands grew up by deposition of peat and colluvial sediments. The fossil beetles were deposited in the PB-7 layer where human artefacts and vertebrate remains have been found in the same spatial and temporal context. The assemblage includes 13 families, documented by 285 skeletal remains of fossil beetles. Ten ecological groups were identified and related to riparian, epigean, Nothofagus sp. forests, and lotic environments such as streams and ponds. Dung and fungi beetles were also part of the fossil assemblage. Pollen and carpological investigations in the same strata point towards the presence of wetlands and evergreen North Patagonian rainforest communities in the Pilauco site during the Upper Pleistocene. However, this study reveals that the Pilauco fossil beetles do not completely conform to any of the known modern assemblages. Therefore, we interpret that the fossil beetle assemblage from Pilauco is the result of the coexistence of different small pockets of habitats in a reduced spatial setting during a period of deep environmental/anthropic changes at the end of the last glaciation. The carabids and dung beetles from these beds indicate that the wetlands may have undergone dry conditions for undetermined periods of time. Finally, we compare nearly contemporaneous beetle assemblages of the sites Pilauco and Monte Verde II to discuss differences and similarities between the sites.

We present an exceptionally long and continuous coastal lacustrine record of ∼5500 years from Lake Huelde on the west coast of Chiloe Island in south central Chile. The study area is located within the rupture zone of the giant 1960 CE Great Chilean Earthquake (MW 9.5). The subsequent earthquake-induced tsunami inundated Lake Huelde and deposited mud rip-up clasts, massive sand and a mud cap in the lake. Long sediment cores from 8 core sites within Lake Huelde reveal 16 additional sandy layers in the 5500 year long record. The sandy layers share sedimentological similarities with the deposit of the 1960 CE tsunami and other coastal lake tsunami deposits elsewhere. On the basis of general and site-specific criteria we interpret the sandy layers as tsunami deposits. Age-control is provided by four different methods, 1) 210Pb-dating, 2) the identification of the 137Cs-peak, 3) an infrared stimulated luminescence (IRSL) date and 4) 22 radiocarbon dates. The ages of each tsunami deposit are modelled using the Bayesian statistic tools of OxCal and Bacon. The record from Lake Huelde matches the 8 regionally known tsunami deposits from documented history and geological evidence from the last ∼2000 years without over- or underrepresentation. We extend the existing tsunami history by 9 tsunami deposits. We discuss the advantages and disadvantages of various sedimentary environments for tsunami deposition and preservation, e.g. we find that Lake Huelde is 2–3 times less sensitive to relative sea-level change in comparison to coastal marshes in the same region.

The extant elephants are only a small fraction of the diverse order of proboscideans that once roamed the planet, whereas the extinct gomphotheres represent the largest and most diverse of these enigmatic groups that survived into the Quaternary. However, their relationship to the living elephantids and the other extinct elephantiformes, such as the mastodons, remains debated. To begin to address this we have used proteomic analysis to sequence the collagen surviving in sub-fossil Notiomastodon bone from the site of Pilauco in Chile. Through the genus-level information retrieved, phylogenetic analyses of the near-complete (85–90%) sequences that were recovered surprisingly revealed a closer relationship between the South American gomphothere (Notiomastodon) and the American mastodon (Mammut) than to the elephantids (Loxodonta, Elephas and Mammuthus), as most commonly proposed; a finding that was consistent across all phylogenetic analyses used, including bayesian, parsimony and maximum likelihood approaches. These results demonstrate the potential information that can be recovered using the ever-increasing applications of proteomics to palaeobiology, particularly for improving our understanding of the evolution of extinct species in a manner consistent with the latest DNA-based approaches.

At Chaihuín marsh, south of Valdivia (39°56’ S/73°33’ W), a sand bed was deposited during the 1960 earthquake. The aim of this study is to map the 1960 tsunami deposit in detail and to associate earlier sand layers with past tsunamis. Geologic field mapping by means of stratigraphic sections constructed using 111 cores in the marsh revealed the existence of three sand layers. The source of these sand layers was determined by a statistical comparison of their sedimentological and mineralogical signatures with modern depositional environments. The results show that tsunami waves probably transported the sand layers found in the marsh. It is inferred that these sand layers were deposited in the marsh by tsunamis that followed subsidence associated with the great historical megathrust earthquakes of 1575, 1737 or 1837, and 1960. However, the three layers are different from each other in terms of lateral distribution and source, which we interpret as either changes in the sand bar associated with human occupation or differences in coseismic slip distribution resulting in variable accommodation space provided by coseismic subsidence as well as in tsunami wave height.

In 1960 CE, Lake Cucao on Chiloe Island in south central Chile was inundated by the tsunami of the Great Chilean Earthquake (Mw 9.5). The area of what is now the lake basin has been submerged since the end of the rapid postglacial sea-level rise and has recorded tsunami inundations in its sediment record since then. This study reconstructs the tsunami history of Lake Cucao. Reflection-seismic profiles and side scan sonar data of the lake reveal a tidal delta with a crosscutting channel, which controls the sedimentary environment in the coast-facing part of Lake Cucao. The convergent pattern of seismic reflections near this channel indicates that tidal currents were active in the lake at least episodically since the formation of a major unconformity with strong reflection amplitude, which records the onset of lacustrine sedimentation. A radiocarbon date at the base of one of the 21 collected sediment cores dates this reflector to ~3800 years BP. Little net vertical displacement (≤2 m) in combination with an outlet river channel that can act as a pathway for sediment transport appears to have maintained the sensitivity of Lake Cucao to record tsunami inundation. The sedimentary record contains 15 clastic layers which are interpreted as tsunami deposits. The confidence level on the tsunami interpretation depends on five site-specific criteria, which are: (i) high magnetic susceptibility of the sediment indicating high clastic content, (ii) cross core correlation indicating widespread deposition, (iii) acoustic reflector correlation to the sedimentary record (also indicating widespread deposition), (iv) presence of mud clasts, and (v) age correlation to known paleotsunamis in the area. In this way, eight clastic layers are interpreted as tsunami deposits with a high confidence level, five with a medium confidence level and two with a relatively low confidence level. This study adds a long paleotsunami record on a coastline where extreme tsunamis occur frequently and where long (>2000 years) paleotsunami records are still sparse.

The forestry industry is known for negatively affecting stream quality when proper management is not applied. Nutrient retention by soils and streamside vegetation buffer strips could attenuate these impacts. We tested the response of different streams to the nutrients and sediments released by a) fertilization and b) clear-cutting of Eucalyptus globulus plantations growing on volcanic soils in southern Chile. We expected the exports to decrease as the remnant streamside native forest width (SNFW) increased. The response to fertilization was restricted to the days immediately after the nutrient addition. On the contrary, most of the nutrients analysed (nitrate, ammonium, dissolved organic nitrogen, phosphate, and total phosphorus) showed a long-term response to clear-cutting. The observed trends were not affected by the SNFWs included in this study (2.5-22 m). Regarding sediments, there were no differences compared to the control watershed, probably due to improvements in the implemented management practices. We conclude that a SNFW < 22 m is not sufficient to avoid the loss of nutrients released by clear-cutting, as it is for sediments. The analysed SNFWs were smaller than those established by Chilean regulations (maximum 30 m) and our results support claims for wider riparian widths in order to effectively filter the nutrients and sediments that influence streams.

The present study describes the discovery of a singular sedimentary structure corresponding to an ichnite that was excavated at the paleo-archaeological site Pilauco (Osorno, Chile). The trace fossil is associated with megafauna bones, plant material and unifacial lithic tools. Here we present a detailed analysis of the Pilauco ichnite and associated sedimentary structures, as well as new radiocarbon data. The ichnological analysis confidently assigns the trace to the ichnospecies Hominipes modernus-a hominoid footprint usually related to Homo sapiens. Some particular characteristics of the Pilauco trace include an elongated distal hallux, lateral digit impressions obliterated by the collapsed sediment, and sediment lumps inside and around the trace. In order to evaluate the origin of the ichnite, trackmaking experiments are performed on re-hydrated fossil bed sediments. The results demonstrate that a human agent could easily generate a footprint morphology equivalent to the sedimentary structure when walking on a saturated substrate. Based on the evidence, we conclude that the trackmaker might well have been a bare-footed adult human. This finding, along with the presence of lithic artifacts in the same sedimentary levels, might represent further evidence for a pre-Clovis South American colonization of northern Patagonia, as originally proposed for the nearby Monte Verde site.

Proboscideans are so-called ecosystem engineers and are considered key players in hypotheses about Late Pleistocene megafaunal extinctions. However, knowledge about the autoecology and chronology of the proboscideans in South America is still open to debate and raises controversial views. Here, we used a range of multiproxy approaches and new radiocarbon datings to study the autoecology of Chilean gomphotheres, the only group of proboscideans to reach South America during the Great American Biotic Interchange (∼3.1 to 2.7 million years before present). As part of this study, we analyzed stable isotopes, dental microwear, and dental calculus microfossils on gomphothere molars from 30 Late Pleistocene sites (31° to 42°S). These proxies provided different scales of temporal resolution, which were then combined to assess the dietary and habitat patterns of these proboscideans. The multiproxy study suggests that most foraging took place in relatively closed environments. In Central Chile, there is a positive correlation between lower δ13C values and an increasing consumption of arboreal/scrub elements. Analyses of dental microwear and calculus microfossils have verified these leaf-browsing feeding habits. From a comparative perspective, the dietary pattern of South American gomphotheres appears to be constrained more by resource availability than by the potential dietary range of the individual taxa. This multiproxy study is aimed at increasing knowledge of the life history of gomphotheres and thus follows an issue considered one of the greatest challenges for paleontology in South America, recently pointed out by the need to thoroughly understand the role of ecological engineers before making predictions about the consequences of ecosystem defaunation.

Dillehay, Tom D. et al., Simple pebble tools, ephemeral cultural features, and the remains of maritime and terrestrial foods are present in undisturbed Late Pleistocene and Early Holocene deposits underneath a large human-made mound at Huaca Prieta and nearby sites on the Pacific coast of northern Peru. Radiocarbon ages indicate an intermittent human presence dated between ~15,000 and 8000 calendar years ago before the mound was built. The absence of fishhooks, harpoons, and bifacial stone tools suggests that technologies of gathering, trapping, clubbing, and exchange were used primarily to procure food resources along the shoreline and in estuarine wetlands and distant mountains. The stone artifacts are minimally worked unifacial stone tools characteristic of several areas of South America. Remains of avocado, bean, and possibly cultivated squash and chile pepper are also present, suggesting human transport and consumption. Our new findings emphasize an early coastal lifeway of diverse food procurement strategies that suggest detailed observation of resource availability in multiple environments and a knowledgeable economic organization, although technologies were simple and campsites were seemingly ephemeral and discontinuous. These findings raise questions about the pace of early human movement along some areas of the Pacific coast and the level of knowledge and technology required to exploit maritime and inland resources., We thank the NSF (grant 0914891), the National Geographic Society (grant 8935-11), Rebecca Webb Wilson and Spencer Wilson, and the Vanderbilt University for supporting our work., We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI).

Stable isotope analyses have been performed on the bioapatite (δ13C; δ18O) and collagen (δ13C; δ15N) of four late Pleistocene South American megafaunal taxa (Notiomastodon platensis, Equus andium, cf. Hemiauchenia paradoxa and Xenarthra indet.) to evaluate paleoclimatic and paleoenvironmental conditions as well as paleoecological features of this time period. The analyzed megafauna was found at several locations in the northwestern Chilean Patagonia (38°–42°S, 74°–71°W). The bioapatite δ13C values indicated the presence of C3 vegetation ranging from forestal to woodland areas. The collagen δ15N values pointed to temperate and humid ecosystems, and to the consumption of shrubs, trees, grasses and sedges. Mean annual temperatures estimated from bioapatite δ18OPO4 values show a similarity to modern temperatures and suggested that the megafauna under study may have lived during warm stages (interstadials) of the late Pleistocene. When comparing our results with those obtained from other South American regions, we find that the diet of this particular Chilean megafauna appears to have been more influenced by resource availability than by the potential dietary range of the taxa., L. Domingo acknowledges a Spanish Ministerio de Economía y Competitividad Juan de la Cierva postdoctoral fellowship and project CGL 2013-43257-R. C. Tornero is a postdoctoral researcher funded by a Juan de la Cierva-Incorporación (no.: IJCI-2014-19909) grant from the Ministry of Economy and Competitiveness, Spanish Government. M. Pino is a researcher funded by FONDECYT grant 1150738. We are also grateful for the funding provided by CGL 2016–80000 -B (MINECO) y SGR 2014 -901 (Gencat). E. González-Guarda kindly thanks Becas Chile, Programa Formación Capital Humano Avanzado for their financial support. We are also grateful for the funding provided by NSF EAR-1148181 grant that enabled us to analyze and radiocarbon date the following CAMS samples: 175749; 175048; 175049; 175733; 175743 and 175744.

The date of the first settlement of the Americas remains a contentious subject. Previous claims for very early occupation at Pedra Furada in Brazil were not universally accepted (see Meltzer et al. 1994). New work at the rockshelter of Boqueirão da Pedra Furada and at the nearby open-air site of Vale da Pedra Furada have however produced new evidence for human occupation extending back more than 20 000 years. The argument is supported by a series of 14C and OSL dates, and by technical analysis of the stone tool assemblage. The authors conclude that the currently accepted narrative of human settlement in South America will have to be re-thought. The article is followed by a series of comments, rounded off by a reply from the authors.

Lake sediments contain valuable information about past volcanic and seismic events that have affected the lake catchment, and they provide unique records of the recurrence interval and magnitude of such events. This study uses a multilake and multiproxy analytical approach to obtain reliable and high-resolution records of past natural catastrophes from similar to 600-yr-old annually laminated (varved) lake sediment sequences extracted from two lakes, Villarrica and Calafquen, in the volcanically and seismically active Chilean Lake District. Using a combination of micro-X-ray fluorescence (mu XRF) scanning, microfacies analysis, grain-size analysis, color analysis, and magnetic-susceptibility measurements, we detect and characterize four different types of event deposits (lacustrine turbidites, tephra-fall layers, runoff cryptotephras, and lahar deposits) and produce a revised eruption record for Villarrica Volcano, which is unprecedented in its continuity and temporal resolution. Glass geochemistry and mineralogy also reveal deposits of eruptions from the more remote Carran-Los Venados volcanic complex, Quetrupillan Volcano, and the Huanquihue Group in the studied lake sediments. Time-series analysis shows 112 eruptions with a volcanic explosivity index (VEI) >= 2 from Villarrica Volcano in the last similar to 600 yr, of which at least 22 also produced lahars. This significantly expands our knowledge of the eruptive frequency of the volcano in this time window, compared to the previously known eruptive history from historical records. The last VEI >= 2 eruption of Villarrica Volcano occurred in 1991. Based on the last similar to 500 yr, for which we have a complete record from both lakes, we estimate the probability of the occurrence of future eruptions from Villarrica Volcano and statistically demonstrate that the probability of a 22 yr repose period (anno 2013) without VEI >= 2 eruptions is

Estudios han establecido que la adopción de sistemas de declaración electrónica reduce los costos de cumplimiento tributario, como también la frecuencia de las empresas visitadas por funcionarios de la administración del Estado. Esto ha derivado en que países de Latino América implementen auditorías tributarias conectándose directamente a los sistemas electrónicos de los contribuyentes. Sin embargo, este tipo de auditorías oculta un conflicto más complejo frente a la vulneración de los derechos de los contribuyentes. Así, el presente artículo entrega un análisis sistemático y técnico sobre la forma como los países en estudio han desarrollado procedimientos de auditoría tributaria a través de sistemas electrónicos, cuyas evidencias demuestran asimetrías en la regulación normativa frente a los derechos de los contribuyentes.

We present a preliminary description and taxonomic assignment of the Lamini fossil remains recovered from the paleontological site of Pilauco (late Pleistocene) in southern Chile. Based on metric variables the fossils are temporarily asigned to cf. Hemiauchenia paradoxa Gervais & Ameghino 1880, waiting for new and more diagnostic remains. We present and discuss some taphonomic processes occurring within the site, starting from the study of the marks observed in the surface of the fossils, wich are consistent with the bog environment with occasional fluvial flooding described for the site.Se presenta la descripción y asignación taxonómica preliminar de los restos de Lamini recuperados en el sitio paleontológico de Pilauco (Pleistoceno tardío) ubicado en el sur de Chile. Sobre la base de variables métricas los materiales son provisoriamente incluidos en cf. Hemiauchenia paradoxa Gervais & Ameghino 1880 a la espera de materiales más diagnósticos. Se discuten algunos procesos tafonómicos ocurridos al interior del yacimiento a partir del estudio de las marcas registradas en la superficie de los fósiles, las que son concordantes con el ambiente palustre con inundaciones esporádicas fluviales descrito para el sitio.

Se analizan e interpretan 14 fosiles correspondientes a dientes y huesos de caballo registrados en el sitio Pilauco, Osorno (40°39' S-73°07' W). El sitio se formo asociado a un pantano en un borde del antiguo rio Damas; en el se ha conservado abundante material de mastofauna y flora pleistocenica. Una fecha radiocarbonica de 11457 ± 140 A.P obtenida de un molar, es concordante con el modelo de edad del sitio. La identificacion taxonomica permite asociar a los fosiles a la especie Equus (Amerhippus) andium, lo que confirma la presencia de la especie en el centro-sur de Chile. Por otra parte, la posicion geografica de los hallazgos y la reconstruccion del paisaje indicarian que se trata de ejemplares cuyas adaptaciones en los metapodios son concordantes para el paisaje pleistocenico de Pilauco dominado por suelos volcanicos blandos, con presencia de bosquetes dispersos en grandes extensiones de praderas de gramineas.

El presente trabajo tiene por objetivo dar a conocer una experiencia de extensión universitaria y educativa con niños/as y jóvenes del sur de Chile, en la cual ellos aprenden sobre patrimonio utilizando el método científico como vehículo de conocimiento y valoración. Nuestro quehacer está basado y se sustenta en las investigaciones de los hallazgos paleontológicos y arqueológicos realizados en Pilauco y Monte Verde. Ambas experiencias las hemos orientado hacia la llamada Paleontología Social, que entendemos integrada con la arqueología de los primeros pobladores y que se sustenta en los conceptos de patrimonio e identidad.

Late Pleistocene sedimentary deposits outcropping around Valdivia city, locally known as Cancagua, have been subject of contrasting interpretations, from glacial to interglacial sediments. Opposing views emerge from focusing on upstream or coastal sedimentary controls, within a zone were these potentially overlap through a full glacial cycle. Here we present the first detailed facies analysis and a broad chronological framework, reconciling previous interpretations in a single paleogeographic model that encompasses the last glacial cycle. Seven facies associations are described, interpreted as an estuarine complex developed primarily during the last glacial cycle’s highstand, yet accumulating sediments during a substantial part of the falling stage. These results offer the opportunity to extend paleoenvironmental records through a full glacial cycle in northern Patagonia.

This paper quantifies two important native forest ecosystem services in southern Chile: water supply and recreational fishing opportunities. We analyzed streamflow in relation to forest cover in six watersheds located in the Valdivian Coastal Range (39850 0 –40805 0 S), the effect of forest management on streamflow in two watersheds in the Valdivian Andes (600–650 m of elevation; 39837 0S), and fish abundance as a function of forest cover in 17 watersheds located in the Coastal Range and the Central Depression (39850 0 –42830 0 S). We found that the annual direct runoff coefficient (quickflow/ precipitation) and total streamflow/precipitation in the dry summer season were positively correlated with native forest cover in the watershed (R 2 = 0.67 and 0.76; * P = 0.045 and 0.027, respectively) during four years of observations. Conversely, a negative correlation was found between summer runoff coefficients (total streamflow/precipitation) and cover of Eucalyptus spp. and Pinus radiata plantations (R 2 = 0.84; * P = 0.010). We estimated a mean increase of 14.1% in total summer streamflow for every 10% increase in native forest cover in the watershed. The analysis of streamflow changes between two paired watersheds dominated by native secondary Nothofagus stands, one thinned with 35% of basal area removal and a control, showed that the former had a 40% increase during summer (four years of observations). The best correlation between fish abundance and forest cover was found between trout abundance (%) and secondary native forest area in 1000 m � 60 m stream buffers (R 2 = 0.65, *** P < 0.0001). We estimated a 14.6% increase in trout abundance for every 10% increase of native forest cover in these buffers. Similar approaches to quantify forest ecosystem services could be used elsewhere and provide useful information for policy and decision-making regarding forest conservation and management.

Con el propósito de conocer las correlaciones genéticas entre los rasgos de crecimiento en toros y las características reproductivas en vacas cebú de Cuba, se utilizaron 9490 registros de toros que terminaron la prueba de comportamiento en pastoreo, a los cuales se les registró el peso final (PF) a los 18 meses de edad; así mismo se emplearon 13.575 registros de sus medio hermanas, a las que se les registró la edad a la primera inseminación (EPI), la edad al primer parto (EPP) y los servicios por gestación (SXG). Los datos fueron colectados en cinco centros genéticos entre 1988 y 2001. Todos los animales eran hijos de 267 toros. Los valores promedios encontrados fueron 343,3 kg, 26,5 meses, 37,7 meses y 1,76 para PF, EPI, EPF y SXG, respectivamente. Los índices de herencia (h²) fueron 0,245, 0,054, 0,091 y 0,021 para PF, EPI, EPP y SXG, respectivamente. Las correlaciones genéticas entre PF y los rasgos reproductivos oscilaron entre -0,216 y -0,340. Entre los caracteres reproductivos, las correlaciones genéticas fueron de 0,544 a 0,982. Se concluyó que los valores de h² estimados para el ganado cebú en Cuba están dentro del rango publicado en la literatura internacional y que la selección continuada para el incremento del peso corporal a los 18 meses de edad en los toros no afectaría negativamente la eficiencia reproductiva en las vacas. In order to know the genetic correlations between the growth characteristics in bulls and the reproductive characteristics in Zebu cows of Cuba, 9.490 registries of bulls were used. They finished the test of behavior in pasturing, and to which the final weight (PF ) at 18 months of age, and 13.575 registries of their half-sisters was registered with the age to the first insemination (EPI), the age to the first childbirth (EPP) and the services by gestation (SXG). The data were collected in five Genetic Centers between 1988 and 2001. All the animals were children of 267 bulls. The values found averages were of 343,3 kg, 26,5 months, 37,7 months and 1,76 for PF, EPI, EPP and SXG, respectively. The indices of inheritance (h²) were of 0,245, 0,054, 0,091 and 0,021 for PF, EPI, EPP and SXG, respectively. The genetic correlations between the reproductive PF and characteristics oscillated between -0,216 and -0.340. Between the reproductive characters, the genetic correlations went from 0,544 to 0.982. One concluded that the values of h² considered for Zebu cattle in Cuba are within the rank published in the international literature and that the selection continued for the increase of the corporal weight to the 18 months of age in the bulls would not negatively affect the reproductive efficiency in cows

Questions surrounding the chronology, place, and character of the initial human colonization of the Americas are a long-standing focus of debate. Interdisciplinary debate continues over the timing of entry, the rapidity and direction of dispersion, the variety of human responses to diverse habitats, the criteria for evaluating the validity of early sites, and the differences and similarities between colonization in North and South America. Despite recent advances in our understanding of these issues, archaeology still faces challenges in defining interdisciplinary research problems, assessing the reliability of the data, and applying new interpretative models. As the debates and challenges continue, new studies take place and previous research reexamined. Here we discuss recent exploratory excavation at and interdisciplinary data from the Monte Verde area in Chile to further our understanding of the first peopling of the Americas. New evidence of stone artifacts, faunal remains, and burned areas suggests discrete horizons of ephemeral human activity in a sandur plain setting radiocarbon and luminescence dated between at least ~18,500 and 14,500 cal BP. Based on multiple lines of evidence, including sedimentary proxies and artifact analysis, we present the probable anthropogenic origins and wider implications of this evidence. In a non-glacial cold climate environment of the south-central Andes, which is challenging for human occupation and for the preservation of hunter-gatherer sites, these horizons provide insight into an earlier context of late Pleistocene human behavior in northern Patagonia.

Within the framework of the studies focusing on the Pleistocene peopling of the Americas, our French-Brazilian team has undertaken a pluridisciplinary research on different archaeological sites, inside and in the neighborhood of the Serra da Capivara National Park, in Brazilian Nordeste. The present study regards an archaeological site, Vale da Pedra Furada, situated in the Piauí state in Brazil. The results of technological and functional studies suggest the existence of different successive human occupations during the Pleistocene in this region. Moreover, the geological and geomorphological studies shed new light on our understanding of sedimentary processes and confirm that the levels were not subject to any significant post-depositional processes. This is also confirmed by macro- and micro-analysis of quartz artefact surfaces. The chronological study has recently been completed employing both radiocarbon and luminescence techniques; radiocarbon dates were obtained on charcoal, multi-grain and single-grain OSL ages on sedimentary quartz grains. The results obtained with the different methods are consistent with each other: the most recent archaeological level is dated to around 8 ka and the oldest to 24 ka, indicating the open-air site of Vale da Pedra Furada to be a succession of human occupations beginning from OIS 2. These results are discussed in the context of some archaeological sites studied in the Serra da Capivara National Park of the last few decades., Authors would like to thank Bordeaux-Montaigne University (PSE 2014), the Conseil Régional d'Aquitaine, the FUMDHAM (Fundacão Museu do Homem Americano), the CNPq and the French Ministry of Foreign Affairs for funding. This project benefited from French State help managed by the French Research National Agency under the Investissements d'Avenir Program (reference ANR-10-LABX-52). Thanks also due to B. Berthier, J-P Dumoulin and C. Moreau for LMC14-AMS facilities at Saclay, and to J. Faure for precious help in preparing luminescence samples.

Several studies relating land cover to stream properties have used sample sizes of more than 100 watersheds, but the variance that they explain is moderate to low (R 2 less than 50%), limiting the predictive value of these studies when their models are applied to watersheds that were not included in the models’ development. We hypothesize that this is due to the increases in variation that occur with increases in sample size and in the geographic scales of the areas in which the watersheds are distributed. Land cover alone cannot explain all of that variation; more predictors must be considered. Conversely, models with high explicative power would require relatively small sample sizes distributed over small areas. This hypothesis was evaluated sampling 17 watersheds from southern Chile’s Lake Region, for which we developed regressive models between land cover/watershed area/precipitation/geomorphology and stream properties (i.e., conductivity, temperature). With a maximum n = 15 watersheds, on a regional scale, a poorly explained variation in hydrologic variables (mean 37–49%) was obtained. The R 2 increased slightly, to 45–52%, when precipitation was included as a predictor. In half of the cases analyzed, the models improved when geomorphology was considered as an additional predictor (60–66%), supporting our hypothesis. Furthermore, when our analysis was restricted to a narrower latitudinal span (n = 9), the R 2 was much stronger (68–87%) when only land cover and watershed area were included as predictors. These percentages also increased when more predictors were incorporated. Nevertheless, a portion of unexplained variance remained that would require the consideration of more predictors, such as geology and edaphology. The documented trade-off provides evidence that argues against the spatial generality of land cover/stream property models.

The result of long-term environmental and human interaction is a variety of potential human responses to major natural crises: population aggregation or dispersal, changes in economic strategies and land-use patterns, restructuring of social organization, increase in the incidence of conflict and warfare, and, in some instances, urban abandonment and cultural collapse. In the context of pre-industrial societies, two social processes with the greatest potential impact on the environment and on changing human-environmental interaction are urbanization and the development of diversified, regional-scale production systems such as intensive agriculture, pastoralism and exploitation of maritime resources. This paper employs archaeological and geological data from the Jequetepeque and Zana valleys on the north coast desert of Peru to study: (1) the specific responses of Moche, Chimu and Inca societies ( c. ad 250–1553) to major episodes of drought, El Niño flooding, and desertification; (2) the social processes of urban-rural relations and economic diversification; and (3) how these processes interacted within the dynamic arid north coast. Our research focuses on changing palaeoenvironmental regimes, agricultural infrastructures and domestic occupations to explore the complex interplay of cultural and natural forces that shaped the variable human responses and the history of urban-rural systems. Understanding the problem of how pre-industrial systems were sustained or failed in the context of interrelated social and environmental crises is an interdisciplinary objective, one that requires the integration of analytical techniques and theoretical frameworks of both the natural and social sciences as delineated in this study.

During the late Pliocene, development of the Panama isthmus allowed North American cervids to expand their distribution to South America (Woodburne et al., 2006). At least eight cervid genera have ...

Stretches of deep ocean are potent barriers to the dispersion of nearshore, benthic marine taxa. Such obstacles can be overcome, however, by species that have either a protracted pelagic larval development or a benthic life-history stage that can be transported by rafting (1, 2). The oyster Ostrea chilensis lacks an extended pelagic larval phase and has discrete populations in New Zealand and Chile that are separated by one of the largest extents (>7000 km) of open ocean on the planet. We tested competing dispersal hypotheses for this species by using ontogenetically informative, dated fossil and sub-fossil shell material, as well as molecular phylogenetic analyses. Our data show that dispersal by rafting is by far the most likely explanation for trans-Pacific range extension by this oyster, and we reject competing hypotheses of vicariance, anthropogenic introduction, and dispersal by ancestral lineages with extended larval development. The presence of 0. chilensis in Chile is important because it clearly demonstrates that transoceanic range extension by rafting is potentially available to a significant fraction of nearshore marine biotas.

The identification of human artifacts at the early archaeological site of Monte Verde in southern Chile has raised questions of when and how people reached the tip of South America without leaving much other evidence in the New World. Remains of nine species of marine algae were recovered from hearths and other features at Monte Verde II, an upper occupational layer, and were directly dated between 14,220 and 13,980 calendar years before the present (∼12,310 and 12,290 carbon-14 years ago). These findings support the archaeological interpretation of the site and indicate that the site's inhabitants used seaweed from distant beaches and estuarine environments for food and medicine. These data are consistent with the ideas that an early settlement of South America was along the Pacific coast and that seaweeds were important to the diet and health of early humans in the Americas.

Paleontological and archaeological sites have frequently been found in open locations of the Intermediate Depression of south-central Chile. This paper presents the results of two field sampling seasons carried out at the Pilauco Site (ca. 39°S) and compares them with those of three well known sites in Chile: Quereo, Tagua-Tagua and Monte Verde, ca. 32°, 34° and 41°S, respectively. Stratigraphic data collected at Pilauco and the resulting radiocarbon age model suggest that before 12,540 ± 90 BP the old Damas River eroded an older volcaniclastic hill, which was followed by a bog formation in an ox-bow lake. The site was developing up to 11,004 ± 186 BP, the date of the youngest vertebrate fossil. Two younger peat beds seal the site. As in Tagua-Tagua and Monte Verde, Gomphotheres are the most represented megafauna. Fossils of Equidae, Camelidae, Cervidae, Mephitidae, Muridae, Myocastoridae and Xenarthra are also found in Pilauco. As a whole, 718 bones, 30 teeth and 11 coprolites represent the extinct and extant vertebrates. Preliminary taphonomic results suggest action of various agents in the bones, i.e. trampling, root etching, abrasion, and carnivore gnawing. The spatial analysis suggests the transfer of smaller anatomical units (e.g. bones of camelids and horses) and the rearrangement of some pieces comparatively large (e.g. gomphothere bones). Similar to the present day north Patagonian landscape, the area where Pilauco site is located had a variety of animal resources, plants and stones in an ecotone between hills, floodplains and wetlands. A total of 101 lithics were recorded: basalt and quartzite were collected from nearby fluvial deposits and dacitic obsidian from the local volcaniclastic deposits. Debitage is the most represented lithic item (75%); cores and marginal edge-trimmed artifacts represented 12 and 13%, respectively. Artifacts and flakes are spatially and temporality associated in the same PB-7 bed with high bone concentrations in some specific areas, between 361 and 424 cm of local altitude. This industry is characterized by a recurrent lithic expedite technology with production of flakes and chips which mastered marginal retouches over the bifacial trimming. This seems to be connected to strategic conditions of high resource diversity, especially of human groups with a high or medium mobility across land. Pilauco represents a site contemporaneous to Monte Verde related as well to the first human occupation in the southern cone of South America, but with higher mammal diversity.