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

In multiparty contexts, we know that affective polarization tends to cluster in ideological blocs, although the factors driving this process are still quite unexplored. In this paper, we contribute to filling this gap in the literature by exploring the capacity of ideological identity vis-à-vis issue-based ideology to polarize sentiments towards party voters into two opposing left-right blocs. Specifically, we provide empirical evidence that affective attachments to ideological labels increase the affective distance between ideological blocs to a greater extent than issue extremity and issue consistency. These bipolarizing effects of ideological identity persist even when the identity is inconsistent with issue-based ideology. Additionally, we show that bipolar affective polarization exerts little reverse influence on ideological identity. We support these arguments using an original survey from the TRI-POL project carried out in five multiparty systems: Argentina, Chile, Italy, Portugal and Spain. [ABSTRACT FROM AUTHOR]

This paper discusses the challenges and opportunities for cross-border eruption management between Chile and Argentina, focussing on an examination of the 2011–2012 eruption of Cordon Caulle in Chile and other crises between 2012 and 2015. We discuss the differences between Chile and Argentina in volcano monitoring, eruption impacts, eruption management and governance during this timeframe. We also discuss the issues in communication of the risks and the potential for future integration at the scientific level. The study is based on 31 interviews with scientists and local officials in 2014–15 (15 in Chile and 16 in Argentina), a questionnaire survey of 128 Argentinian residents in 2015 and a questionnaire survey of 25 disaster managers and residents of Pucón during the 2015 eruption of Villarrica volcano. We conclude that in 2011–12, there were issues with communication across the border, particularly at the political level, and that there are important ways that the scientific institutions in both countries complement each other. • We present new social data concerning the 2011–12 eruption of Puyehue Cordon Caulle. • We show that the eruption was significant in the evolution of institutions and agreements between the countries. • We show that locally, there was dissatisfaction with risk communication in Argentina (which was worse affected). • We argue that the scientific institutions complement each other well but need more resourcing from government. [ABSTRACT FROM AUTHOR]

Patagonia features the most extensive glaciers of the Southern Hemisphere, excluding Antarctica, and a vast inventory of glacial landforms, so it is thought to have played a key role in (paleo)glacier studies since the late 19th century. However, no systematic attempts to characterize the specific research trends and the scientific community focused on Patagonian cryosphere have been conducted so far. To fill this gap, we analyzed the metadata associated to 305 articles compiled from the Web of Science database following a bibliometric approach covering the period between 1976 and 2020. Our results point to an irregular but net increase on the number of contributions on Patagonian (paleo)glaciers. Mass balance analyses based on satellite data of present-day glaciers and the reconstruction of past glacier activity by dating glacial landforms formed during the Last Glacial Termination, were the most addressed topics during the analyzed period. Patagonian (paleo)glacier studies are mostly published in generic Earth Sciences publications, followed by Quaternary and glaciological journals. Most of the studies were led by scientists from the United Kingdom, followed by Chile, Argentina and United States. In terms of collaborations, these studies can be divided into two main clusters, one composed by researchers from United States, Chile and Argentina institutions, and another mostly composed by British researchers. So far, the most prolific authors are nearly equally distributed in nationality, yet gender inclusion and international collaborations are still caveats that must be solved. Even though our query on the Web of Science missed highly influential (so-called) grey literature, such as local scientific journals and technical reports, the reviewed scientific literature unambiguously indicates that Patagonia is a privileged location for (paleo)glaciers studies worldwide and that it will continue offering vast opportunities to tackle critical questions related to global cryosphere and past-to-present climate changes. • Patagonia is a privilege site for studying present and past glacier dynamics and the evolution of climate changes at hemispheric and global scale. • Glacier dynamics during the 20th century and and the Last Glacial Termination are the most common topics addressed in past decades in the WOS. • Patagonian (paleo)glacier studies has contributed to the development or improvement of diverse analytical techniques. • United Kingdom, United States, Chile and Argentina produced the largest number of WOS-listed papers on (paleo)glaciers in past decades. • The related scientific community is fairly heterogeneous. Although, inclusion and international collaboration issues still need to improve. [ABSTRACT FROM AUTHOR]

This paper provides new trace element and Sr-Nd-Hf-Pb-O isotope data on Neoproterozoic to Phanerozoic mid to upper crustal lithologies of the Andean basement in central Chile and western Argentina (33°-35°S; 69°-72°W). It also provides additional data on trench sediments being subducted offshore the northern segment of the Southern Volcanic Zone in Chile. Neoproterozoic metamorphic and igneous rocks from the Guarguaráz complex (Argentina; 33.6°S, 69.5°W), when back corrected to 350 Ma, display a narrow range in 87Sr/86Sr i (0.713–0.718), 143Nd/144Nd i (0.5118–0.5121), εNd i (−8.1 to −1.1), εHf i (−11.4 to +1.2) and δ18O (9–13‰). Nd model ages (T DM = 1.08–1.65 Ga) for the Guarguaráz complex points to a Mesoproterozoic crustal residence age for these rocks. Metasedimentary rocks from the Carboniferous accretionary prism in central Chile (~34°S) overlap with these ranges, but differ by having lower initial 87Sr/86Sr i (0.7052–0.7093) and higher δ18O (14–17‰). The Guarguaráz metamorphic and igneous rocks, when back corrected to 350 Ma, have similar Pb isotope ratios than the Chilean Carboniferous metasedimentary rocks (206Pb/204Pb i = 17.58–18.52 vs. 18.33–18.46; 207Pb/204Pb i = 15.50–15.64 vs. ~15.64; 208Pb/204Pb i = 37.70–38.36 vs. 37.98–38.18). Two Guarguaráz samples are shifted towards less radiogenic Pb isotope ratios, similar to samples representative of the Cuyania basement. This suggests that Chilenia hosts at least two geochemical components: (1) a component with unradiogenic Pb isotopes, similar to the Proterozoic Cuyania basement, and (2) a component with more radiogenic Pb isotopes, similar to Chilean Phanerozoic metasedimentary and igneous rocks. The ranges in Pb isotope ratios for the Chilean Mesozoic (206Pb/204Pb i = 18.44–19.86; 207Pb/204Pb i = 15.59–15.69; 208Pb/204Pb i = 38.30–40.30) and Miocene (206Pb/204Pb i = 18.43–18.57; 207Pb/204Pb i = 15.58–15.60; 208Pb/204Pb i = 38.33–38.46) igneous rocks are similar to those of the accretionary prism. The Mesozoic and Miocene intrusive rocks are characterized by low 87Sr/86Sr i (0.704–0.708 and ~0.704, respectively) and high εNd i (−6.2 to +4.0 and + 3.9 to +5.9, respectively) and εHf i (+7.0 to +12.7 and + 8.5 to +10.8, respectively). They can be divided into two groups. Group (1), consisting exclusively of Mesozoic samples, has negative εNd i , 87Sr/86Sr i > 0.706, elevated e.g., Ba/Th, Nb/Yb, Zr/Y and lower Nb/La, reflecting derivation from enriched (most likely overriding crust or mantle) material. Group (2), consisting of Mesozoic and Miocene rocks, has positive εNd i , εHf i , and lower initial 87Sr/86Sr i than group (1) reflecting depleted mantle melts addition to the crust. Finally, Sr-Nd-O isotopic compositions of the trench sediments at latitude 33°-33.3°S are almost identical to those at latitude 35°-40°S, indicating a relative homogeneous material input along the SVZ, although there are subtle differences in REE and Pb isotopic compositions. Based on Nd–Hf isotopes, trench sediments offshore Chile (εNd> +1; εHf > +2) and offshore Peru (εNd < −2; εHf < +1) have distinct compositions, reflecting the differences in input material. The positive εNd and εHf values suggest derivation from eroded depleted mantle-derived mafic material. • New trace element and Sr-Nd-Pb isotope data for SVZ crustal and trench sediment samples. • New whole-rock Hf–O isotope data for crustal and trench sediment samples. • Nd model ages confirm a Mesoproterozoic crustal residence age for the Guarguaráz complex. • NSVZ trench sediments reflect the source composition of eroded mafic material. [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]