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Abstract: In extra-Andean Patagonia, wet meadows contrast with the prevailing arid steppes, and present a gradient of water availability from the periphery to the center. The objectives of this paper are to describe the spatial and temporal variation of aerial net primary production (ANPP) of Patagonian meadows, and to obtain a model for the relationship between the normalized difference vegetation index (NDVI) and ANPP. We determined ANPP in four regionally scattered meadows during 3–5 years and in three positions of the gradient of water availability. In one meadow, we correlated ANPP with NDVI during 2 years. Annual ANPP was 2–3 times larger in the center than in the periphery, and also varied 2–3 fold among the four meadows. The interannual variation of ANPP was high and similar across meadows and zones. ANPP was closely correlated with NDVI through a linear model. Within the growing season, the central zone had a more extended period of high NDVI into the summer than the peripheral and the intermediate zones. We conclude that (1) the local variation of ANPP across the gradient of water availability is strong and must be taken into account for management, and (2) the highly variable ANPP may be monitored by remote sensing. [Copyright &y& Elsevier]

Abstract: The average age at sexual maturity (ASM) is an important parameter for evaluating the reproductive potential or status of a population. South American sea lions, Otaria flavescens in Patagonia (Argentina) were exploited and reduced to less than 10% of pre-exploitation numbers. At present, the population is recovering at a rate of 6%. In this paper, we studied growth and age at sexual maturity of South American sea lions in the south-western south Atlantic by examining 219 individuals (females and males) collected between 1989-2008. Individuals were aged by counting growth layer groups in tooth sections, standard body length was measured and male and female reproductive organs were examined macroscopically and histologically to establish individual sexual maturity. Maximum recorded length for males and females was 264cm and 200cm, respectively, and maximum ages 19 and 21 yrs. ASM defined as the age where 50% of females are mature, was estimated at 4.8±0.5 years old, corresponding to a mean SL of 147cm, about 81% of their asymptotic length. First observed ovulation occurred during the 4th year, first birth may occur between 4 and 5 years old. Males physiologically mature between 4-6 years, but the size of the testes shows that all males became sexually mature by the age of 9 years when they reach a mean SL of 212cm, about 86% of their asymptotic body length. The present information on ASM and growth of O. flavescens will improve the development of population dynamics models, to investigate the impact of recovering sea lions populations on its marine environment, as well as its trophic interactions with commercial fisheries. [ABSTRACT FROM AUTHOR]

This paper focuses on the anxiety of possession that underlies the anthropological inquisitiveness of the nineteenth-century Argentine explorer Francisco Pascasio Moreno. Moreno's Viaje a la Patagonia Austral (1879) exposes a series of complex representational configurations that respond to specific national imperatives. Although Moreno negates the native peoples' presence by depicting them as relics, his anthropological curiosity paradoxically makes evident that Patagonia was visibly populated by indigenous peoples. Significantly his portrayals of 'Indian' rituals make references to sex and violence, as well as allusions to female chastity. Since these elements are seldom overtly present in Europeans' narratives of travel and exploration on Patagonia, these representations constitute a break from the writing travel tradition that precedes Moreno's. But, more importantly, these references to uncontrolled passions and female virginity expose the ambiguities of a narrative that, while providing an account of a visibly inhabited Patagonia, also attempts to legitimize Argentina's colonizing project in the region.El presente trabajo centra su atención en las ansias de posesión que subyacen a la curiosidad antropológica del explorarador argentino decimonónico, Francisco Pascasio Moreno. El texto de Moreno, Viaje a la Patagonia Austral (1879), expone una serie de configuraciones representacionales complejas que responde a imperativos nacionales específicos. Si bien Moreno al representar a los pueblos originarios como reliquias niega la presencia de éstos, su curiosidad antropológica paradójicamente pone en evidencia que la Patagonia estaba poblada por indígenas. Es signficativo que sus descripciones de los rituales de los 'indios' hacen referencia al sexo y a la violencia así como también a la castidad femenina. Dado que estos elementos rara vez están tan explícitamente presentes en narrativas europeas de viaje y exploración a la Patagonia, estas representaciones constituyen un quiebre con la tradición que precede a Moreno. Pero, aún más importante, estas referencias a pasiones incontrolables y a la virginidad femenina exponen las ambigüedades de una narrativa que da cuenta de una Patagonia visiblemente habitada y que, al mismo tiempo, intenta legitimar el proyecto colonizador argentino en la región. [ABSTRACT FROM AUTHOR]

This paper describes a simulation model combining the main components of water balance and growth of perennial grassland steppe in Chilean Patagonia, to estimate long-term annual production (Yr, kg ha-1) and sheep carrying capacity (GC, sheep equivalent [EO] ha-1). The model is based on climate-water balance relationships, where the basic process is evapotranspiration. The model calculates Yr depending on the accumulation of transpiration and the water use efficiency from the time of growth initiation until the grassland accumulates the maximum amount of dry matter (DM). Depending on Yr, the DM requirement of EO, the proper use factor of grassland and a slope correction factor, a range site GC is calculated. Simulations were performed using actual climate data sets of eight growing seasons at Kampenaike (52°41' S; 70°54' W; 12 m.a.s.l.) and a long-term simulation in the same location, using a stochastic weather variables generator. Through the model it was possible to estimate the water loss associated with the components of water balance and estimate the restriction imposed by water deficit on Yr. By simulating many years, it was possible to establish a normal distribution of GC with 0.629 EO ha-1 yr-1, associated with 80% probability of being exceeded, which is lower than values reported in field assessments. This method calculates GC with a conservational approach, taking into account soil and climatic variability in semiarid ecosystems. [ABSTRACT FROM AUTHOR]

Abstract: This paper evaluates the chronology of the last glacial cycle and deglaciation in the Lago Pueyrredón valley of central Patagonia, 47.5° S, Argentina. The valley was a major outlet of the former Patagonian Ice Sheet and the moraines that record its fluctuations are an important proxy record of climate change in southern South America. Such moraines are well-preserved in the Lago Pueyrredón valley owing in part to the semi-arid environment east of the mountain front. Here, we provide the first direct chronology for the age of the “Rio Blanco” moraine system by utilizing cosmogenic-nuclide surface exposure ages. Boulders on the moraines give 10Be exposure ages that indicate the Last Glacial Maximum (LGM) maximum extent occurred by 27–25ka. Subsequent advances occurred at 23–22ka, 20–18ka, and ca. 18–17ka. Initial deglaciation began after ca. 18–17ka and was interrupted as evidenced by the Lago Columna moraines up-valley. Subsequently the outlet glaciers occupying both the Lago Pueyrredón basin (Chilean name: Lago Cochrane) and the Lago Buenos Aires basin (Chilean name: Lago General Carrera) to the north, rapidly retreated more than 80km at around 16.5–15ka. The timing of the LGM maximum extent and the onset of deglaciation occurred broadly synchronously throughout Patagonia. Deglaciation resulted in a series of interconnected glacier-dammed lakes in the region that initially drained toward the Atlantic Ocean and later drained to the Pacific Ocean as a consequence of disintegrating ice in the Andes. [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: Annual growth rings are well-defined in some shrubby species distributed along the Patagonian steppe and provide useful information to identify the environmental factors that influence the radial growth of shrubs in the region. However, little is known about variations in ring width from these species and their relationships with local environment. In this paper we present 18 growth ring width chronologies covering the last 2–3 decades from the shrub Anarthrophyllum rigidum (Fabaceae) encompassing most of its natural range of distribution in Argentina. Interannual variations in growth were first analyzed collectively to identify common regional patterns. In addition, shrub growth at each site was compared with local climate records and site-specific characteristics. Based on a principal component analysis (PCA), sites were joined in four major groups related to the site proximity to the Andes (foothills versus Patagonian plateau) and latitude (north versus south Patagonia). The relatively similar percentage of PCA variance associated with each group reflects environmental differences among sites. Consistent with this observation, we noted large variability in the responses of the A. rigidum woody growth to regional climatic fluctuations. At most sites, this species is favored by abundant winter precipitation, warmer spring and autumn temperatures (controlling the duration of the growing season), cool summers, or a combination of these factors. However, deviations from these patterns are also recorded. Our study represents the first large-scale dendroclimatological analysis of a shrubby species in southern South America. The results presented here provide information on the main patterns and factors affecting the growth of A. rigidum in Patagonia, and may be useful for determining well-suited practices for management and conservation of this ubiquitous species. [Copyright &y& Elsevier]

Abstract: This paper presents an updated, extensive review of glacier fluctuations during the past 1000years in the extratropical Andes of South America between ca. 17° and 55°S. Given the variety of environmental conditions and evidence available for glacier fluctuations across this wide latitudinal range, regional accounts are given for the Desert Andes (∼17°–31°S), the Andes of central Chile and Argentina (31°–36°S), and the North (36°–45°S) and South (45°–55°S) Patagonian Andes. The techniques, dating limitations, and interpretations of the glacier records along this transect are also discussed. Information on glacier fluctuations in the Desert Andes is limited to the 20th century. Documentation on past glacier variations is more abundant in the Central Chilean-Argentinean Andes, but the number of chronologies dealing with glacier fluctuations prior to the 1900s is also limited. Most records indicate that glaciers were generally more extensive prior to the 20th century, with dates of maximum expansion ranging from the 16th to the 19th centuries. The number and extent of glaciers increase significantly in the Patagonian region, where the evidence available for dating glacier variations during the past centuries is more abundant and the dating control for glacier events is generally better than in the northern parts of the study area. For some Patagonian glaciers, maximum Little Ice Age (LIA) or post-LIA advances have been precisely dated by dendro-geomorphological determinations or in situ measurements. However, for most sites, the evidence available is still preliminary and there is considerable variability in the extent and timing of events related to the maximum LIA expansion identified in most areas between the 16th and 19th centuries. Evidence is starting to appear at a growing number of sites for glacier advances during the first half of the past millennium. These events were generally less extensive than the LIA maximum pulses. Despite the occurrence of several post-LIA readvances over the past 100–110years, most areas in the Andes of extratropical South America have experienced a general pattern of glacier recession and significant ice mass losses. The differences in the glacier histories observed at local and regional scales probably reflect the inherent limitations associated with the glacier records and/or the dating techniques used in each case together with the varying dominance of precipitation, temperature and other climatic and non-climatic factors on glacier mass balance and glacier dynamics. These differences indicate that the late Holocene glacier history of southern South America is more complex than commonly assumed. The evidence discussed in this study highlights not only the immense potential for glaciological studies of this region but also a significant need for an increased number of detailed, well-dated records of glacier fluctuations. [Copyright &y& Elsevier]

The present paper provides 9 new records of Trichoptera species, for Northwestern Patagonia, Argentina. The family Tasimiidae and Verger affinis (Schmid), V. bispinus (Schmid) and V. obliquus (Schmid) (Limnephilidae) are cited for Argentina for the first time. The distribution of some species of Helicophidae, Hydrobiosidae, Limnephilidae and Philorheithridae is updated. [ABSTRACT FROM AUTHOR]

The Odonata order is represented in Patagonia by 36 species belonging to nine families and 18 genera. The endemicity level is high being approximately 60% of the species and 40% of genera endemic. The specific richness in Patagonia decreases from West to East and from North to South, being Nahuel Buta (Chile) and Andes mountains between 38° and 41° S on the forest area, and the Somuncurá plateau (Argentina) on the steppe the richest areas. An update of its records and an analysis of the main distribution patterns are provided in this paper. [ABSTRACT FROM AUTHOR]

Abstract: Hydrogen safety issues and especially hydrogen hazard''s address are key points to remove any safety-related barrier in the implementation process of hydrogen energy systems. Demonstrative systems based on hydrogen technologies represent a clear contribution to the task of showing the feasibility of the new technologies and their beneficial capabilities among the public. In this paper, the safety features of the first hydrogen energy demonstrative plant conceived in Latin America are analyzed. The facilities, located in the village of Pico Truncado, Patagonia, Argentina, serve to gain day-to-day experience in the production, storage, distribution, conversion and use of hydrogen in several applications. The plant uses electrolysis to generate pure hydrogen from renewable primary sources, taking advantage of the installed wind power capacity that is continually growing in the region. The installations were designed to accomplish with two primary objectives: total safety assurance and minimization of human errors. Some details of the plant, including a general layout, are presented here, in addition with design criteria, hydrogen hazards, structural precautions, gas monitoring system, existing regulations and safety requirements. [Copyright &y& Elsevier]

This study focuses on textile production in the Central Plateau of the Province of Chubut (Patagonia Argentina). This kind of textile production is similar to the one practiced by the ancient inhabitants of the Patagonia region, which is described in historic documents of the 16th Century. Using a combination of ethnographic and historical research methods, I study the main characteristics of current textile production in the Patagonia region, and how these are firmly rooted in the past. In this paper I discuss the technical and instrumental details of textile production, how it is transmitted through generations, and its importance for the economy of the families who practice it, both in the present and in the past. I also examine how identity is created in the process of textile production. I adopt a structuralist perspective on the analysis of textile production, and I depart from a primordialist and static concept of culture. [ABSTRACT FROM AUTHOR]

During last years as much in the frame of the celebration of the 100 years public festivities of both most important cities located in the Gulf San Jorge basin (Comodoro Rivadavia and Caleta Olivia) as in the most recent commemoration of the centenary of the discovery of the oil in the zone, women appropriated diverse uses of the past to ask for the right to have a past. Beyond the public festivities which were arranged from the official sphere, the petroleum companies or the mass media, an important group of women organized different commemoration practices; the publication of books and photographic samples stood out among them. It has allowed a fruitful exchange among people who are in the academy and out of it. In the paper I try to show that this memoralist outbreak in terms of gender, having revalued topics such as the child-rearing, the family care, the informal sociability puts the emphasis on the domesticity and the exaltation of the kinship networks to emphasize the rol of women in that past. As the cult of motherhood represented social inclusion for these women, in this work I suggest that it is again the articulation of women - maternity - family - history - nation what returns to center stage, but those who promote such social commemoration practices have created places of memory in the center of the sphere of production: places where the men had dominated historically. [ABSTRACT FROM AUTHOR]

Cayenne (Thalasseus sandvicensis eurygnathus) and Royal Terns (Thalasseus maximus) breed in mixed colonies in Argentina. This paper presents the first detailed information on their breeding diet and assesses differences and overlap between species in the type and size of prey. During 2004 and 2005, observations of prey delivered to mates and chicks were carried out at Punta León, Patagonia. The diet of Cayenne and Royal Terns comprised nine and 10 prey species respectively. Fish comprised >99% of the prey of both species of tern in the two study years. Both species had a fairly specialised diet based on pelagic schooling fish, mostly Argentine Anchovy (Engraulis anchoita) and two species of silversides (Odontesthesspp.). Despite observed overlap in trophic resources, our results showed that Argentine Anchovy was the main prey for Royal Terns, whereas the two species of silversides together with Anchovy comprised the bulk of the diet for Cayenne Terns. Fish delivered by Cayenne Terns were significantly smaller than those by Royal Terns. Results suggested that both type and size of prey may be important factors permitting food partitioning between the two species of tern during the breeding season. [ABSTRACT FROM AUTHOR]

The lowering of global sea level during the Pleistocene by more than 100 m and subsequent inundation of coastal areas constitutes a problem in terms of general research on early maritime-oriented societies. However, post-glacial isostatic rise in glaciated regions has produced raised shorelines of Late Pleistocene/Early Holocene age, e.g., in Scandinavia, Patagonia, and North America. As these regions contain the oldest preserved coastal areas, they are imperative for the understanding of the development of maritime hunter-gatherers. The extensive Norwegian coastline appears to have been colonized in the course of the few hundred years around 9500 cal B.C. An overwhelming majority of Early Holocene sites are found in the fiord/skerry coastal landscape, indicating that marine resources were vital in the subsistence pattern of people occupying the region. The lithic tradition is clearly linked to specialized megafauna hunters in the continental plains (the Ahrensburgian complex of northwestern Europe), but the facts about and dynamics of the development of the marine subsistence pattern are unclear. This paper focuses on this problem-with comparative perspectives towards the emergence of maritime foragers in Patagonia. [ABSTRACT FROM AUTHOR]

Patagonia and Tierra del Fuego include contrasting environments and populations. Both were settled more than 10,000 years ago, although the coastal resources were not intensively exploited until four millennia later. The littoral resource exploitation had very different characteristics on the Atlantic compared to the Magellan-Fuegian coasts. Generalized strategies were maintained in the former, while in the latter the inhabitants developed a specialization—they became intensively dependent on the littoral and marine resources and designed special technological means for their procurement and processing, including navigation capability. This process began some 6,400 radiocarbon years ago and these sea-nomads colonized the southern- most archipelago from the Beagle Channel down to Cape Horn. After synthesizing the settling of Patagonia, this paper focuses on the process of colonization and cultural endurance of the seanomads until the time of European contact. [ABSTRACT FROM AUTHOR]

In this paper, transformations of internal links within the indigenous political field are explored, focusing on the last decades of the frontier. This period, in which the state progresses towards its political unification and institutional consolidation, state policies regarding Indian people show a more unified profile and aim to create the conditions necessary for the frontiers advance. The peace treaties policy, extended to almost the whole indigenous map, will be one of the devices through the state will attempt to canalize and to order its relations with different chiefs and groups. Our interest attempts to identify the probable conditionings and influences of this policy on the indigenous population at the conformation, strengthening and weakening of their political alliances. We intend specifically to reconstruct-within this context-the process of the Calfucurá's leadership, to identify the impact of state interventions over the extent of his political summoning capacity during this period. [ABSTRACT FROM AUTHOR]

The interpretation of the meanings of constructed space plays an important role in understanding how a certain society might have been structured in the past. This paper presents the colony of Floridablanca (Patagonia, 18th century) and examines how the different discourse levels are articulated in the construction of the colony's spaces according to the ideal model of a social order based on the principles of the Spanish Enlightenment. The focus is on the convergence and divergence between the material world and the narratives referring to such spaces created during the existence of the colony. This approach, developed by an interdisciplinary team, involved the inclusion and interpretation of historical, archaeological, and geophysical data. Studied along three lines of evidence, the narrative analyses and material construction show how the discourse on the social organization of Floridablanca articulates convergence and divergence from these planes in different ways for different sectors of the colony. [ABSTRACT FROM AUTHOR]

The south of Patagonia is characterized by its semi-arid weather and numerous small, temporary and permanent shallow ponds. The aquatic crustaceans of these water bodies are characterized by their endemism and species richness. The present study was done in the surroundings of Punta Arenas (53°S, Chile), and included six shallow ponds. Samples for conductivity, total dissolved solids, chlorophyll, and crustacean zooplankton as well as littoral species of crustacea were collected. Our study revealed that Branchinecta gaini Daday, 1910 occurred at low conductivity (0.55 mS/cm), and low total dissolved solids (0.28 g/l) and chlorophyll (2.70 μg/l) concentrations, such compared to sites without fairy shrimp populations, that had significantly high conductivity (3.58 mS/cm), and high total dissolved solids (1.80 mg/l) and chlorophyll (12.80 μg/l) concentrations. The results partially agree with the first descriptions of Patagonian water bodies that indicated the presence of fairy shrimps in low conductivity waters. The observations of the presence of B. gaini and other associated microcrustaceans are similar to descriptions of unpolluted water bodies in Antarctica, and those results would support the observations of the present paper. Other reports on fairy shrimp habitats mentioned a wide range of both salinity and trophic status. Other ecological and biogeographical topics on fairy shrimps are also discussed. [ABSTRACT FROM AUTHOR]

Resolving the history of vegetation, fire, and glaciation on the eastern slope of the central Patagonian Andes (44°-49°S) since the Last Glacial Termination (T1) has proved difficult. This is due to the steep environmental gradients, vegetation heterogeneity, and scarcity of dated glacial deposits and geomorphic features. Unsurprisingly, published records show important heterogeneities which limit our understanding of the timing and magnitude of climate and vegetation changes, and their driving mechanisms since T1. In this paper, we describe sediment cores from small closed-basin lakes located in the deciduous Nothofagus forest zone near Coyhaique, Chile. Our results indicate that the Coyhaique glacier lobe abandoned its final Last Glacial Maximum position just before ~17.9 cal kyr BP and underwent a step-wise recession that included a halt/readvance that culminated at ~16.8 cal kyr BP, contemporaneous with the formation of an ice-dammed proglacial lake in the Coyhaique/Balmaceda sector. This glacial lake stood at its highest level between ~17.9–17.2 cal kyr BP (<726 and > 650 m.a.s.l.), lowered between ~17.2–16.2 cal kyr BP (<650 and > 570 m.a.s.l.), and disappeared thereafter. Herbs and shrubs, currently dominant in high Andean and Patagonian steppe environments, colonized the ice-free terrains distal to the glacier margins and proglacial lakes under cold and dry conditions. This was followed by a steady increase in Nothofagus between ~16.6–14.8 cal kyr BP that led to the establishment of forests starting at ~14.8 cal kyr BP. The Holocene started with a sudden increase in Nothofagus and disappearance of conifers in the context of increase fire activity between ~11.7–9.4 cal kyr BP. Closed-canopy Nothofagus forests persisted virtually unaltered from ~9.4 cal kyr BP to the present day, despite frequent explosive volcanism and millennial-scale variations in fire regimes, attesting to their extraordinary postglacial resilience which contrasts with their behavior during T1. Recent large-scale deforestation by fire, livestock grazing, and the spread of non-native invasive plant species drove the fastest and largest-magnitude shifts seen during the last ~16,500 years. • Glacial retreat began at ~17.9 ka and followed a stepwise pattern until ~16.2 ka. • Arboreal Pollen rose at ~16.6 ka driven by stronger Southern Westerly Winds (SWW). • Rainforest conifers peaked between ~14.8–11.7 ka suggesting maximum SWW influence. • Fires and disappearance of conifers suggest weak SWW between ~11.7–9.4 ka. • Extraordinarily resilient Nothofagus forests have persisted since ~9.4 ka. [ABSTRACT FROM AUTHOR]

Our interest in the project focuses on the analysis of the dimensions that approach or prioritize in the text books that account for of the curricular contents on Patagonia: (geographical, historical, political and socio-cultural) in order to determine the contributions of these texts to the construction of the social representations on the territory. The project focuses also in the study of the images used during the period 1884-1957 since they provide us the prospective "marks" that contributed to the construction and production of the social representation of this territory. We choose the school texts to analyze the representation of Patagonia and its inhabitants because there are no studies on them in the subject and because the school texts, as obligatory instruments in school, are the instruments that reflect the hegemonic projects with more or less loyalty. The body of the school texts considered in this project are text productions that circulated in the official and Silesians schools in the period of Argentine territory (1884-1957). For this paper is important to emphasize that texts analyzed were from the beginning of the XX Century until 1944 and from 1957 until 1963. [ABSTRACT FROM AUTHOR]

This paper presents the first inventory of modern and sub-fossil taxa of the Family Chironomidae (Insecta: Diptera) from Nahuel Huapi National Park in Patagonia, Argentina. The catalogued fauna contains 104 species in 48 genera and 6 sub-families for modern fauna and 52 morphotypes in 36 genera and 4 subfamilies for sub-fossil fauna. [ABSTRACT FROM AUTHOR]

This paper presents the first inventory of modern and subfossil taxa of the Family Chironomidae (Insecta: Diptera) from Nahuel Huapi National Park in Patagonia, Argentina. The catalogued fauna contains 104 species in 48 genera and 6 sub-families for modern fauna and 52 morphotypes in 36 genera and 4 subfamilies for sub-fossil fauna. [ABSTRACT FROM AUTHOR]

As part of the research project called "School textbooks. Images and representations. The building of Patagonia in the school imaginaries. Rio Negro and Neuquén (1884-1957)", we are working upon representations concerning Patagonia in school textbooks either state or religious ones (from the Salesian order), previous and subsequent to the peronist period. Some of the images we have been able to trace in such sources include those of Patagonia as indigenous and deserted, Patagonia as a source of oil, Patagonia as the end of our Homeland, as well as Patagonia for tourists when associated to an Argentinian Switzerland. Such representations were the result of an analysis of geographic, historical and economic contents as found within the texts, either in written language or iconography.This line of work has been followed through the selection, for this paper, of a corpus composed of sixty school textbooks known as Manuales Estrada from such period, bearing in mind that hegemonic government policies gave a crucial importance to the inclusion of certain contents through school textbooks.From a qualitative perspective, we focus on historical, geographical and natural resources contents that allow to identify some elements to define Patagonia's images, as a central purpose of our research. [ABSTRACT FROM AUTHOR]

This paper describes the diversity, taphonomy and palaeoecology of angiosperm leaves that dominate a palaeoflora of Cretaceous (Cenomanian–Coniacian) age from the Mata Amarilla Formation in the Austral Basin, south-west Patagonia, Argentina. Twelve morphotypes of angiosperm leaves are recognized based on foliar morphotype analysis of more than 500 specimens. These were divided into six morphological groups based on major architectural patterns. The relative dominance of these morphotypes, mode of preservation and relationship with sedimentary facies were evaluated from two levels within the formation. This analysis identified two different plant palaeocommunities. The lower, María Elena, level (MEL) was deposited in a marine coastal area on a subaerial delta plain; the dominant angiosperm morphotypes preserved in it are group 1 (MA100) and group 2 (MA101, 102); morphotypes MA109 and 110 are scarce but exclusive to this level. The upper, Mata Amarilla, level (MAL), accumulated inland in flood-plain environments; the most abundant angiosperm morphotypes are groups 3 (MA103–105), 4 (MA106) and 1 (MA100); morphotypes MA103–105 and 108 are exclusive to this level. Comparisons with other floras of similar age from Antarctica, Australia and New Zealand indicate that the Mata Amarilla flora has a slightly higher morphological diversity of angiosperm leaves, providing the first evidence for an angiosperm-dominated early Late Cretaceous macroflora in south-west Gondwana. [ABSTRACT FROM AUTHOR]

This paper studies the function of textual space in Final de novela en Patagonia (2000), by Mempo Giardinelli. The hypothesis of this research states that the novel is influenced by stereotypes of the Patagonian foundational texts (distance, desert, emptiness) for two main reasons: first, because the narrator himself is not from Patagonia and, secondly, because these narrative clichés are meant to serve artistic purposes. The "Thirdspace" theory, by Edward Soja, is used here to study the connection between a perceived spatiality, the conceived spatiality, and the lived spatiality. The basic contribution of Soja's theory is in its strategy called "Thirding-as-Othering" which challenges the traditional duality of thinking and performing critical analysis. [ABSTRACT FROM AUTHOR]

The starting point of our investigation is the hypothesis that the non-standard Patagonian variety is made up not only of phonological, grammatical and lexical features, but also of oral interaction patterns which are essentially different from those used in urban societies. Therefore the purpose of this paper is to investigate everyday conversations from a socio-pragmatic approach, in order to give account of the relationship between this form of verbal exchange and the socio-cultural context where its production occurs. Our analysis is based on data collected during a field research carried on in two Mapuche-Tehuelche communities of the province of Chubut, in the Argentine Patagonia: Blancuntre and Cerro Centinela. Recorded spontaneous dialogues and personal interviews form the Corpus of analysis. The study focuses on the following structural constituents of conversation: pauses, silences and redundancy, within the frame of a theoretical pattern that allows us to identify a group of socio-demographic variables, which constraints the interacting behavior of the members of the investigated communities. The analysis of the collected corpus shows the relationship between conversational structures and strategies; and the Amerindian culture, where the interaction develops. The conclusion is that cultural diversity clearly emerges from the pragmatic level of language. [ABSTRACT FROM AUTHOR]

This paper studies the role of political organizations, the church, the state and labor unions in the leisure time of the workers in Northern Patagonia from the beginning of the 19"" century, up to the rise of peronismo. We discuss the strategies put into practice by such institutions, as related with the planning and consumption of their spare time. We also analyze each institution's interests, which went far beyond making themselves sure that the workers' could take better advantage of their leisure time. Far from that, these actors' actions were part of a wider strategy that could be combined with the one developed within the workers' world. In the case of political and labor unions' organizations, such actions were related with the spreading of ideas that could be useful to reinforce consciousness for class struggle, to build a new society and additionally, to strengthen trade union structures. The actions of the church, on the other hand, were oriented towards disciplining the working world, christianizing it, and indoctrinating catholic workers in a world of armonic relations between capital and labor and teaching them to reject alterations of the status quo and the workers' ways of participation typical of resistance societies. Finally, actions performed by the State attempted to control, regulate and discipline such workers. [ABSTRACT FROM AUTHOR]

Riverine and wind-borne materials transferred from Patagonia to the SW Atlantic exhibit a homogeneous rare earth element (REE) signature. They match well with the REE composition of Recent tephra from the Hudson volcano, and hence this implies a dominance of material supplied by this source and other similar Andean volcanoes. Due to the trapping effect of proglacial and reservoir lakes, the larger Patagonian rivers deliver to the ocean a suspended load with a slightly modified Andean signature, that shows a REE composition depleted in heavy REEs. In this paper we redefine Patagonia as a source of sediments, which is in contrast with other sources located in southern South America. Quaternary sediments deposited in the northern and, to a lesser extent, in the southern Scotia Sea, and most of the dust in ice cores of east Antarctica have REE compositions very similar to the loess from Buenos Aires Province and to Patagonian eolian dust. However, we rule out Buenos Aires province as a Holocene major source of sediments. Similarly to Buenos Aires loess (a proximal facies), it is likely that the REE compositions of most sediment cores of the Scotia Sea and Antarctica reflect a distal transport of dust with an admixed composition from two main sources: a major contribution from Patagonia, and a minor proportion from source areas containing sediments with a clear upper crustal signature (e.g., western Argentina) or from Bolivia’s Altiplano. Evidence indicates that only during the Last Glacial Maximum, Patagonian materials were the predominant sediment source to the southern latitudes. [Copyright &y& Elsevier]

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

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

This paper models the extent of the Patagonian icesheet during the Last Glacial Maximum (LGM) and its subsequent deglaciation. It constrains a new coupled icesheet/climate numerical model with empirical evidence and simulates the icesheet at the LGM and at stages of deglaciation. Under LGM conditions an icesheet with a modelled volume slightly in excess of 500,000 km3 builds up along the Andes. There is a marked contrast between the maritime and continental flanks of the modelled icesheet, with positive mass balance exceeding 2 m in the west and declining tenfold to the east. Modelled ice velocities commonly reach 400 m yr−1 in the western fjords. The model is most sensitive to variations in temperature and good agreement between modelled ice extent and empirical evidence was achieved by applying a temperature decrease of 6°C relative to present day temperatures with constant wind fields over the model domain. Assuming a stepped start to deglaciation, modelled ice volumes declined sharply, contributing 1.2 m to global sea level, 80% of it within 2000 years. The empirical record suggests that such a stepped warming occurred around 17,500–17,150 cal yr ago. [Copyright &y& Elsevier]

Abstract The purpose of this paper was to synthesize observations of 21 cold temperate lakes from Patagonia, Argentina. To do this, objective limnological variables and the phytoplankton summer structure were analysed using multivariate statistical tools. The results suggest that the most important variables defined a trophic gradient based on nutrients, conductivity and phytoplanktonic attributes. Cluster analysis pointed to three groups of lakes. Steppe lakes (group III) were distinguished from mountain-Andean lakes (groups I and II) through their higher conductivity and ammonia concentration values, higher net phytoplankton density and lower species diversity. The two groups of Andean lakes differed with regard to the biomass of Bacillariophyceae and Prymnesiophyceae, water temperature and dissolved inorganic nitrogen concentration. The influence of the biomass (as biovolume) of each taxonomic group in lakes of different trophic status was examined. Although all Andean lakes appear to be similar, as shown by their similar salt and nutrient concentration values, the phytoplankton biomass split into different taxa and clearly distinguished subgroups. The work presents original information about the phytoplanktonic community structure from all the lakes and the first limnological data on 10 of them, from a region that is poorly known. [ABSTRACT FROM AUTHOR]

Simple Summary: Determining the impacts of human activities on natural populations is important for biodiversity conservation. In this paper, we study the past and more recent effects of urbanization and livestock activity on the genetic diversity and population structure of endemic guanaco populations of the arid Monte and Patagonian Steppe of central Argentina. Our results reveal that urbanization, the installation of fences, and the competition from sheep grazing coincided with the isolation of several guanaco populations, especially in areas with the highest intensity of livestock activity. However, our genetic analyses suggest that a more recent increase in connectivity among groups is occurring. Our results highlight the importance of implementing conservation management plans for natural populations in arid and human-intervened environments. Extensive livestock production and urbanization entail modifications of natural landscapes, including installation of fences, development of agriculture, urbanization of natural areas, and construction of roads and infrastructure that, together, impact native fauna. Here, we evaluate the diversity and genetic structure of endemic guanacos (Lama guanicoe) of the Monte and Patagonian Steppe of central Argentina, which have been reduced and displaced by sheep ranching and other impacts of human activities. Analyses of genetic variation of microsatellite loci and d-loop revealed high levels of genetic variation and latitudinal segregation of mitochondrial haplotypes. There were indications of at least two historical populations in the Monte and the Patagonian Steppe based on shared haplotypes and shared demographic history among localities. Currently, guanacos are structured into three groups that were probably reconnected relatively recently, possibly facilitated by a reduction of sheep and livestock in recent decades and a recovery of the guanaco populations. These results provide evidence of the genetic effects of livestock activity and urbanization on wild herbivore populations, which were possibly exacerbated by an arid environment with limited productive areas. The results highlight the importance of enacting conservation management plans to ensure the persistence of ancestral and ecologically functional populations of guanacos. [ABSTRACT FROM AUTHOR]

Zooarchaeologists have relied upon various approaches to study the impacts of harvest pressure and environmental change on ungulate populations, such as analysis of prey mortality patterns and morphometrics. Analysis of ancient DNA from ungulate bones and bone fragments from archaeological sites provides an additional means for studying prey population dynamics related to environmental change and human ecology over time. In this paper, we study the population history of the largest game animal in northwest Patagonia, the guanaco (Lama guanicoe). Our study relies on the use of Bayesian Skyline Plots to determine shifts in estimated guanaco population size based on analysis of ancient mitochondrial DNA. Our results indicate that hunting by humans in addition to increases in aridity during the late Holocene led to a decline in the guanaco population in the region, which is in contrast to the harvest and environmental history in other parts of Patagonia (south of our study area). Using a weight of evidence approach that includes proxies of environmental change, human population dynamics, exploitation of guanacos, and estimates of guanaco population size, we argue that the late Holocene shift in guanaco population size was a driving factor in subsistence and settlement change related to resource intensification during the late Holocene in northwest Patagonia. • Demographic reconstruction of guanaco population dynamics during the Holocene. •Estimated population size is based on ancient DNA analysis through Next Generation Sequencing. •There are key changes in guanaco population size during the late Holocene. •Late Holocene guanaco population relates to increased hunting pressure in northwest Patagonia. [ABSTRACT FROM AUTHOR]

The main goal of this paper is to review the earliest archaeological evidence for the presence of humans in Fuego-Patagonia. The paleoenvironmental and paleoclimatic framework is briefly introduced, followed by a discussion of its relevance to understanding the exploration and colonization of Fuego-Patagonia. Technological and faunal evidence from a number of sites from the southern extreme older than 10,000 B.P. is analyzed. This leads to the conclusion that an early entry, at least 12,000 years old, appears best to accommodate the available chronological evidence. On the other hand, data from the Northern fringes of Patagonia clearly suggest an earlier human colonization. [ABSTRACT FROM AUTHOR]

The provenance of sandstones deposited in the late Paleozoic Tepuel-Genoa Basin is analyzed in this paper. Five sections were sampled in Esquel, Sierra de Tepuel, Sierra de Tecka, El Molle, and Río Genoa areas for petrographic and geochemical studies. The sandstones in the Tepuel-Genoa Basin are dominated by feldspathic litharenites and litharenites, showing lithic fragments of volcanic and sedimentary rocks in the Valle Chico Formation and medium-to high-grade metamorphic rock clasts in the rest of the units. Detrital modes of seventy-five sandstones samples from the Valle Chico, Pampa de Tepuel, Mojón de Hierro, and Río Genoa formations were counted and analyzed. Seven modal components have discriminant value for identifying provenance areas (Qm, Qi, Lv, Lmm-h, Lm-Lp, Lm, Qpm). These modal components allow identification of three petrofacies: 1. Quartzose-lithic (Qm 69 Lv 2 Lm 29), 2. Quartzose (Qm 89 Lv 4 Lm 7) and 3. Volcanic-sedimentary (Qm 60 Lv 38 Lm 1). The quartzose-lithic petrofacies is mainly composed of monocrystalline quartz, medium- and high-grade metamorphic clasts and polycrystalline quartz with cataclastic texture, this assemblage is interpreted as being derived from the crystalline rocks that form the Deseado Massif. The quartzose petrofacies is composed of monocrystalline quartz with scarce contributions of metamorphic clasts and traces of volcanic fragments; the provenance area is ascribed to sedimentary terrains, which most likely covered part of the Deseado Massif. The volcanic-sedimentary petrofacies is comprised of volcanic (acidic and intermediate rocks) and sedimentary (sandstone and mudstone) clasts, with discrete amounts of quartz grains with idiomorph shapes and embayments. This assemblage may correspond to material supply from the Devonian-Early Carboniferous accretionary complex developed in Chile or the unroofing of the western volcanic arc located in the central part of Patagonia. The validity of the three defined petrofacies was evaluated using Principal Component Analysis and triangular compositional diagrams; both methods show good separation and lack of overlap between the three petrofacies. Major (Si, Al, Fe, Na, K) and trace-REE elements (Zr, Th, Sc, Hf) were used to improve the petrographic information. The relation SiO 2 against K 2 O/Na 2 O indicates that the Pampa de Tepuel and the Mojón de Hierro formations correspond to a passive margin, while the Valle Chico and Río Genoa formations represent different types of active continental margins. The Th/Sc and Zr/Sc ratios and the Th-Hf-Co distributions indicate that the sandstones of the Tepuel Group were formed from rocks compatibles with the average composition of the upper continental crust. • Detrital modes of the late Paleozoic Tepuel-Genoa Basin in Patagonia (Argentina) are analyzed. • Geochemical data of sandstones of this basin are presented. • Three petrofacies (Quarztoze, Quarztose-lithic, and Volcanic-sedimentary) are defined. • The basement of the Macizo del Deseado and Chilean accretionary complexes are proposed as the main source areas. [ABSTRACT FROM AUTHOR]

Macroalgae have attracted the interest of remote sensing as targets to study coastal marine ecosystems because of their key ecological role. The goal of this paper is to analyze a new spectral library, including 28 macroalgae from the South-West Atlantic coast, in order to assess its use in hyperspectral remote sensing. The library includes species collected in the Atlantic Patagonian coast (Argentina) with representatives of brown, red, and green algae, being 22 of the species included in a spectral library for the first time. The spectra of these main groups are described, and the intraspecific variability is also assessed, considering kelp differentiated tissues and depth range, discussing them from the point of view of their effects on spectral features. A classification and an independent component analysis using the spectral range and simulated bands of two state-of-the-art drone-borne hyperspectral sensors were performed. The results show spectral features and clusters identifying further algae taxonomic groups, showing the potential applications of this spectral library for drone-based mapping of this ecological and economical asset of our coastal marine ecosystems. [ABSTRACT FROM AUTHOR]

• Extremal hypotheses are evaluated in a pristine Patagonia river system. • A location-for-time-substitution model is used to evaluate extremal hypotheses. • Extremal results can guide further mechanistic research into alluvial channels. • Energy based extremal hypotheses show most promise identifying dynamic equilibrium. The indeterminate channel problem arises from uncertainty in finding a closure relation for alluvial channels created by self-organizing erosional and depositional processes. Extremal hypotheses have been proposed as one potential approach to closing the system of governing equations for alluvial channels. Many different extremal hypotheses have been presented, but no substantive evidence has been developed to select which hypothesis may be most appropriate for natural alluvial river systems. This paper evaluates the ability of ten extremal hypotheses to identify dynamic equilibrium across a geomorphic gradient in the remote and undeveloped mid-latitude watershed of Rio Murta, Chile. This study (a) introduces extremal hypotheses, (b) describes the field site and geomorphic conditions, and (c) examines which extremal hypotheses are supported by the field data in identifying the evolutionary trend toward dynamic-equilibrium. The extremal hypotheses that identified dynamic equilibrium within the geomorphic gradient in the field are: (1) minimum kinetic energy, (2) minimum specific stream power, (3) maximum friction factor, and (4) maximum total friction factor, which collectively support minimizing kinetic energy of the system. [ABSTRACT FROM AUTHOR]

This paper analyzes the distribution patterns of pollen and spore assemblages in modern surface sediments recovered from the bottom of the San Jorge Gulf (SJG) and from offshore sites, in relation to the location of different phytogeographic provinces surrounding the SJG, including the distant forest from southwestern Patagonia. Results reveal that pollen spectra are dominated by Chenopodiaceae-Amaranthaceae, Poaceae, Asteraceae subf. Asteroideae, Colliguaja integerrima and Ephedra sp.; which represents the vegetation adjacent to the SJG. Overall, the pollen distribution in surface sediments reflects the location of the different phytogeographic provinces and will be used as modern-analogues to document vegetation history around the SJG. Pollen assemblages also reveal the latitudinal variation of vegetation taxa in the Patagonian steppe, which is characterized by a slight increase in herbaceous pollen and a decrease in high shrubs (e.g. Colliguaja integerrima) towards the southern-central part of the SJG. Furthermore, we identified two pollen taxa from the southwestern Patagonian forest, Nothofagus and Podocarpus that could be used as indicators of past dynamics and variations of the Southern Westerly Wind Belt (SWWB) in the SJG during the Late Pleistocene and Holocene. High pollen concentrations are recorded at the central part of the SJG (480–8080 grains/g), while low concentrations are measured in the northern and southern parts of the Gulf, as well as at offshore sites (26–1806 grains/g). The pollen distribution in the study area is most likely governed by the SWWB in combination with the marine sediment composition and surface currents flowing through the SJG. • Pollen and spore surface distribution patterns from the San Jorge Gulf. • Pollen assemblages echo different phytogeographic provinces surrounding the gulf. • Nothofagus and Podocarpus reflect long distance transport by westerly winds. • Pollen distribution results from transport by westerly winds and surface currents. [ABSTRACT FROM AUTHOR]

Marine sedimentary rocks of the lower Miocene Monte León Formation of southeastern Patagonia (Austral Basin), Argentina are important geological archives for better understanding regional tectonics, paleoenvironments, oceanography, and climate. In this paper, we describe assemblages of invertebrates, palynomorphs, foraminifera, ostracods and calcareous nannofossils in a stratigraphical and sedimentological framework, which suggest deposition during a transgressive-regressive cycle. From base to top, the lowermost outcropping deposits of the Punta Entrada Member represent an inner shelf environment, formed during a transgressive phase. The zone of maximum flooding is marked by a high diversity of protoperidiniaceans (heterotrophic) and offshore dinoflagellate cysts, an increase in the percentage and size of planktonic foraminifera, and a decrease in shallow water benthic foraminifera. Regressive deposits in the upper part of the Punta Entrada Member exhibit a progradational stratal stacking pattern and are characterized by an upward decrease in bioturbation and in the content of marine invertebrates; the dinoflagellate cyst assemblages point toward shallower and more restricted marine conditions than in underlying deposits. The cycle ends with the Monte Observación Member, which contains an impoverished and mostly reworked fauna of invertebrates. The presence of monospecific reefs of Crassostrea orbignyi , the decrease in dinoflagellate cysts and calcareous microfossils diversity, and the increase of continental palynomorphs suggest progressively shallower conditions and increasing influence of freshwater discharge. Although eustatic controls could have contributed to the sedimentary evolution of the Monte León Formation, the upward regressive trend is interpreted as the result of tectonism linked to the Andean orogeny, which led to the uplift, exhumation, and erosion of the highlands in the west. This is supported by the abundance of pyroclastic material, together with reworked specimens of Upper Cretaceous forams and Upper Cretaceous and middle Eocene dinoflagellate cysts in the upper part of the Punta Entrada Member and in the Monte Observación Member. • Multiproxy data indicate that study rocks represent a transgressive-regressive cycle. • A maximum flooding and/or higher organic flux zone was identified at the coastal cliffs. • The regressive trend was the result of tectonics, sediment supply dynamics, and volcanism. • Cretaceous/Eocene forams and dinocysts evidence exhumation and reworking from the Andes. [ABSTRACT FROM AUTHOR]

Large carbonate microbialite build-ups are relatively uncommon in ancient fresh-water lacustrine basins as compared with those marine and saline environments. This paper discusses the formation of a large continental lacustrine deposit, the Oligocene-Miocene Carinao Formation in Argentina, which contains large bioherms. The lacustrine formation occurs in N-S corridor and is mostly composed by meter scale pinnacles and sheet-like carbonate beds that grade to detrital deposits towards the more subsident southern areas. The main facies are autochthonous and allochthonous limestones and detrital deposits. The autochthonous limestones include the carbonate pinnacles, which are about 4 m high and 0.5 m in diameter and coalesce laterally to form very continuous beds (several kms). The pinnacles are formed by plate-like, dome, vertically elongated and irregular horizontal bioherms, most of them with radial structure. The bioherms are boundstones of fibrous (fans and spherulites) and feather calcite crystals, micrite and inequigranular calcite mosaics. Both biogenic and abiogenic processes interfered in carbonate precipitation. Allochthonous limestones include peloidal, ostracod and intraclastic limestones, some containing coated grains. Polymictic conglomerates and cross-bedded hybrid arenites deposited in a fluvial-deltaic system located at the southwest of the basin. δ13C values vary between −0.4 and −3.2‰ VPDB and δ18O are comprised between −5.7 and −8.6‰ VPDB. The 87Sr/86Sr ratios range between 0.7061 and 0.7056. The Carinao Formation deposited in a fresh-water lake, sourced by meteoric and deep-groundwater. Tectonics was a main control determining the configuration of the lake system, the water supply and the alignment of some bioherms. The vertical succession or the different bioherms morphologies reflects well the lake level changes controlled by both tectonic and climate. [ABSTRACT FROM AUTHOR]

The lower Miocene Santa Cruz Formation (dated to ~18–16 Ma) of Southern Patagonia, Argentina, preserves rich vertebrate faunas, which are representative of communities that existed prior to the Great American Biotic Interchange (GABI). Some previous researchers have hypothesized that these pre-GABI faunas had a low richness of mammalian carnivores (an impoverished predator guild), while others argue for a predator/prey ratio similar to those of recent communities. In this paper, we analyze faunas from the lower part of the Santa Cruz Formation (FL 1–7) using a methodology that allows us to quantify (i) the meat resources that were available to the secondary consumers of the palaeocommunity; and (ii) the competition intensity for these resources. In our modeling, we considered different scenarios related to meat consumption, including the possibility that several taxa had a scavenging behavior, and also differences in mortality rates between young and adult prey. Our results provide estimates of the nutritional requirements from the predator/scavenger guild under maximum and minimum quantities of meat offered by the prey community, which indicate the presence of a well-balanced palaeocommunity. Moreover, the competition indices point to a relatively high level of competition for prey of small-to-medium size, although competition for resources from large mammal prey was rather low. This suggests that the predator/scavenger guild was not impoverished, although there were insufficient carnivore species to fully consume the megaherbivore biomass. • We analyze predator richness of mammalian communities that preceded the Great American Biotic Interchange in Patagonia. • The biomass supplied and required is quantified for palaeocommunites in the Miocene (Burdigalian) Santa Cruz Formation. • The biomass demanded by carnivores falls within the range of biomass available. • Competition intensity was high for small mammalian prey, but low for large ones. • Predator richness was well-balanced in this palaeocommunity, except for large prey. [ABSTRACT FROM AUTHOR]

This paper presents a numerical study to assess the hydrodynamic effects of different levels of biofouling in fish cage aquaculture netting. The methodology adopted includes high resolution Large Eddy Simulation (LES) coupled to a regional model implemented within the framework of the Coastal and Regional Ocean Community Model (CROCO). The physical coherence of this approach has been previously verified and published by the authors. Three levels of biofouling were considered to describe a clean fish cage netting with no biofouling, medium biofouling and high biofouling growth levels. Clean and biofouled fish cage netting were described using a porous media model and the porous media coefficients were taken from the literature. A salmon farm located in the Estero Elefantes Channel in Patagonia (45°39′16.50 S 73°35′59.40 W) was used as study case. A change in the biofouling level in aquaculture fish cages netting can lead to drastic changes in the local velocity field. The high biofouling level produces the largest change in velocity direction and magnitude not only locally in near-cage areas, but also changing features in the overall fjord circulation. Velocity reduction in the shadow zone of fish cages reached values between 30% and 10% of the incident current for null and high biofouling levels, respectively. Simulations also showed dramatic effects of biofouling on flushing time. The predicted water availability of the salmon farm shows decreases of 27% and 36% considering medium and high levels of biofouling. This decrease in the available water is also related to a reduction in the amount of available oxygen and accumulation of waste products, affecting not only the health of farmed fish but also the environment. These and other environmental and productive implications are discussed. • The hydrodynamic effect of biofouled fish cage netting is addressed using coupled regional and LES ocean models. • A change in biofouling level can lead to drastic changes in the local velocity field. • Simulations show dramatic effects of biofouling on flushing time. • Water availability decreases of 27% and 36% considering medium and high levels of biofouling. [ABSTRACT FROM AUTHOR]

The Paleogene infill of the eastern Golfo San Jorge Basin, Patagonia, Argentina, is composed of marine (Salamanca Formation) and terrestrial (Grupo Río Chico and lower Sarmiento Formation) deposits. The Río Chico Group is a fluvial, pedogenically modified succession interlayered with eolian volcaniclastic deposits during the Eocene. Several authors have highlighted the stratigraphic significance and usefulness of strongly developed paleosols in the definition of sequence stratigraphic studies. Even though the area hosts abundant geological and paleopedological data, no large-scale (i.e., basin-scale) stratigraphic architectural correlation including paleosols and relationships within the sequence stratigraphic context had hitherto been carried out. By integrating previously published and unpublished data sets, this paper proposes a sequence stratigraphic framework for the middle Danian–middle Eocene successions of the eastern Golfo San Jorge Basin. Here, spatio-temporal changes in fluvial/alluvial architecture of the Paleogene infill allow us to define four depositional sequences (S), limited by sequence boundaries (SB) that internally presents a low-accommodation system tract (LAST), and a high-accommodation system tract (HAST). Part of these sequences occur as fining-upwards fluvial successions that are pedogenically modified on top by strongly developed paleosols, or are erosively overlain by the coarse-grained base of the following sequence without the development of well-developed paleosols. The sedimentological and paleopedological analysis of the four sequences identified for the early Paleogene infill of the basin indicates that the interplay between subsidence, base level, and climate controlled both fluvial style and landscape evolution, as well as soil development. Volcaniclastic supply also played a significant role, especially during the Eocene. Image 1 • Paleogene infill of the GSJB can be divided into 4 sequences. • Sequence boundaries are related to fluvial incision or to mature paleosols. • Mature paleosols reflect the transition from greenhouse to icehouse world. • Accommodation space, base level and climate controlled system tracts evolution. • Subsidence rates controlled fluvial architecture spatial variability. [ABSTRACT FROM AUTHOR]

In this paper, we present an updated revision of fossil vertebrates from the Chubut Group, Golfo San Jorge Basin, while also describing some new remains. Extensive exposures of both Lower and Upper Cretaceous sedimentary sequences are present in central Patagonia. These outcrops have, over the past several decades, yielded a varied vertebrate fauna, including fishes, turtles, crocodyliforms, pterosaurs, and dinosaurs, currently herein characterized and described. Although vertebrate diversity in the Chubut Group in central Patagonia is remarkable, the most abundant vertebrates recovered are dinosaurs. The Matasiete Formation (Hauterivian?–Albian) is markedly less prolific in terms of fossils discoveries than either the Bajo Barreal Formation (Cenomanian–early Turonian) or the recently recognized Lago Colhué Huapi Formation (Coniacian–Maastrichtian). The Bajo Barreal fauna is, at a high level, typical of coeval Gondwanan faunas. However, interestingly, several taxa occupy a basal position within their respective groups. The Lago Colhué Huapi Formation has produced a more derived vertebrate fauna, again similar to those from other Gondwanan regions. Finally, in a broad context, the new materials described augment our understanding of Cretaceous terrestrial vertebrate assemblage of central Patagonia and add to the generally meager record of vertebrate in the Cretaceous of the Southern Hemisphere. • South-central Patagonia preserves a rich and important vertebrate fossil record. • New materials described augment our understanding of Cretaceous vertebrate. • The information mentioned constitutes an important source for future comparisons. [ABSTRACT FROM AUTHOR]

Fluvial systems provide multiple life-supporting functions, but their values are affected by a range of anthropogenic disturbances. Hydromorphology is used as a conceptual framework for assessing the status of fluvial systems and design river restoration strategies but is rarely applied to nearly pristine environments. This paper presents one of the first assessments of river characteristics and changes in the Aysen Region, an area in southern Chilean Patagonia. The analysis of multitemporal satellite images allowed to define key patterns related to river morphology of the Exploradores river network. The Exploradores basin experienced only limited and recent human disturbances, and fluvial changes are related almost only to natural climatic or geomorphological processes. The river experienced moderate reduction of active channel width and braiding index over the past 70 years. The basin represents a suitable site to study fluvial processes and dynamics in nearly reference conditions, and changes due to the likely increase of human activities and disturbances in the near future. • First assessment of river characteristics and changes in the Exploradores river network, a nearly-pristine basin in Southern Chilean Patagonia. First assessment of river characteristics of the Exploradores river network, a nearly-pristine basin in Chilean Patagonia. • The river experienced moderate reduction of active channel width and braiding index over the past 70 years. The river experienced a moderate reduction of active channel width and braiding index over the past 70 years. • The Exploradores basin could represent a suitable site to study fluvial processes and dynamics in nearly reference conditions. The Exploradores basin could represent a suitable site to study fluvial processes and dynamics in nearly reference conditions. [ABSTRACT FROM AUTHOR]

Hydrothermal eruptions are explosive events driven by the sudden and violent vaporization of the water present in many hot water geothermal fields worldwide. Over recent years, thermodynamical conditions of fluids and petrophisical-geomechanical features of host-rocks were mentioned as responsible of the wide range of eruptive styles and deposits of hydrothermal eruptions. Nevertheless, geological and historical records show that PDC and fallout processes are underestimated as common processes linked to hydrothermal eruptions. This paper analyzes from a multi-disciplinary approach —virtual outcrops modeling, sedimentology, petrographic and XDR studies, facies modeling, eye-witness source analysis, and stratigraphy— the pristine Holocene–historic hydrothermal eruptive record of El Humazo manifestation (Domuyo Geothermal Field, Patagonia, Argentina). Different eruptive scenarios are characterized by ballistic ejection, PDC and/or fallout mechanisms with discernible tefra-composition and granulometry, associated with both excavational and/or aggradational landforms. We show how diverse eruptive dynamics are controlled by pre-eruptive internal and external factors, such as reservoir energy, depth of the explosion/fragmentation levels, physical properties and structural anisotropy of the host-rocks and eruptive center migrations. We consider that this case study may be useful not only for the application in the assessment of the volcanic hazard associated with the Domuyo geothermal field, but also contributes to the knowledge of the eruptive dynamics in other geothermal systems with similar characteristics. • Hydrothermal eruptions show simple or compound mechanisms of transport–deposition. • Energy, fragmentation level, host-rock property control the hydrothermal eruptions. • Host-rock type influences the tephra granolumetry and eruptive dynamics. [ABSTRACT FROM AUTHOR]

Species in the genus Notocotylus (Trematoda, Notocotylidae) are cosmopolitan parasites of mainly aquatic birds and, to a lesser extent, mammals. In this paper we describe Notocotylus primulus n. sp. parasitizing the Crested Duck, Lophonetta specularioides , from the Patagonian coast, southwestern Atlantic Ocean, based on morphological and molecular data. The new species could be distinguished from its congeners by the combination of several features; among them, the position of the genital pore that is prebifurcal and located close to the posterior margin of the oral sucker, a greater number of both ventral papillae and uterine loops, and a large cirrus sac. Molecular results of the ITS2 sequence support the location of this new species in the genus Notocotylus due to a close relationship with Notocotylus malhamensis (the lower genetic distance of the ITS2 sequences). Unlabelled Image • Notocotylus primulus n. sp. is described from Lophonetta specularioides from Argentina. • The new species is morphologically and genetically characterized • It is the first record of a trematode parasite in the endemic Crested Duck. [ABSTRACT FROM AUTHOR]

• 6 metals determined in two edible biomonitors/mollusks (2005 → 2012) Beagle Channel. • MBS → Enhancing information variety → 729 samples/13000 determinations/. • For Cd and Pb, 65%−40% bivalves exceeded max levels of Mercosur. • Mytilus : Cr, Cu, Ni, Pb, Zn → safe for consumption/ EDIs lower → safety refs. doses. • Nacella: → less safe species (high consumers) due to high Cd levels → THQ and H I > 1. The purpose of this paper is to investigate the trace metal content in edible biomonitors (i.e., mollusks) in the Beagle Channel (southern Patagonia) and to assess the human health risks associated with their consumption. Rationale: The monitoring breakdown structure (MBS) conceptual model was applied to four sampling campaigns (2005 → 2012) that collected 729 samples of Mytilus chilensis and Nacella magellanica. The composition of trace elements (Cd, Cr, Cu, Ni, Pb and Zn) in the mollusks was determined using graphite furnace (GFAAS) or flame atomic absorption spectrometry (FAAS). We compared the mean obtained values with the maximum levels (MLs) of each element established by international organizations. Then, based on semi-structured interviews, we calculated the estimated daily intake (EDI) of local residents and compared it with safety reference doses, i.e., the provisional tolerable daily intake (PTDI), provisional maximum tolerable daily intake (PMTDI), and tolerable daily intake (TDI), as well as the benchmark dose level lower confidence limit for Pb (BMDL 01 , a reference point (RP)/point of departure (POD). Moreover, to obtain information about the potential health risks of ingesting heavy metals (HMs) through mollusk consumption, we evaluated the target hazard quotient (THQ) and the hazard index (HI). Findings: For Cd and Pb, 65% and 40% of bivalves exceeded the MLs established by the Mercado Común del Sur (Mercosur), respectively. Except for Cd in N. magellanica (i.e., 1.20 μg/kg/bw/day), EDI values were clearly lower than the safety reference doses. For Cr, Cu, Ni, Pb and Zn, mussels were safe for consumption and did not raise concerns for public health. Likewise, THQ values were well below one for most of the studied metals, indicating that the exposed human population is assumed to be safe. Occasional high consumers of mollusks from the most contaminated sites may be at some health risk. Originality: The food production system and the environment are complex systems; this is crucial to understand when we consider ecosystems as a food source (i.e., marine ecosystems). Here we consider edible biomonitors, that are organisms that can have a dual function. They are food, and at the same time, if properly calibrated, they can act as indicators of environmental quality. This study is the first to investigate relevant essential and non-essential trace metal content in two edible mollusks from the Beagle Channel in a long-term survey (2005 → 2012). The information variety was high; approximately thirteen thousand determinations were conducted to support the risk assessment for mollusk consumption. Other aspects connected with the health risks and the uncertainty factors related to the presence of essential and non-essential minerals in edible mollusks as well as the use of the MBS are also discussed. [ABSTRACT FROM AUTHOR]