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La topografia tiene un rol muy importante en kawesqar, ya que es omnipresente en todo tipo de discurso en esta lengua. Este articulo describe la codificacion de las formas del paisaje en kawesqar. Estos terminos muestran complejas descripciones del paisaje, necesarias para determinar la posicion del hablante, otras personas, animales u objetos en un territorio cuyo paisaje, el de Patagonia occidental, en si es complejo. ABSTRACT Topography has a very important role in Kawesqar (ISO code 639-3), since it is omnipresent in all types of discourse in this language. This paper describes the linguistic encoding of landforms in Kawesqar. Landform terms exhibit complex descriptions of the landscape that are necessary to determine the position of the speaker, other persons, animals or objects in a territory West Patagonia whose lanscape is itself complex.

This study presents the first geochemical data of fluid discharges collected from February 2010 to March 2015 from the Planchón–Peteroa–Azufre Volcanic Complex (PPAVC), located in the Transitional Southern Volcanic Zone (TSVZ) at the border between Argentina and Chile. During the study period, from January 2010 to July 2011, Peteroa volcano experienced phreatic to phreatomagmatic eruption possibly related to the devastating Maule earthquake occurred on February 27, 2010. The compositional dataset includes low temperature (from 43.2 to 102 °C) gas discharges from (i) the summit of Peteroa volcano and (ii) the SE flank of Azufre volcano, both marked by a significant magmatic fluid contribution, as well as bubbling gases located at the foothill of the Peteroa volcanic edifice, which showed a chemical signature typical of hydrothermal fluids. In 2012, strong compositional changes affected the Peteroa gases from the summit area: the acidic gas species, especially SO2, increased, suggesting an input of fluids from magma degassing. Nevertheless, the R/Ra and δ13C–CO2 values decreased, which would imply an enhanced contribution from a meteoric-hydrothermal source. In 2014–2015, the chemical and isotopic compositions of the 2010–2011 gases were partially restored. The anomalous decoupling between the chemical and the isotopic parameters was tentatively interpreted as produced by degassing activity from a small batch of dacitic magma that in 2012 masked the compositional signature of the magmatic fluids released from a basaltic magma that dominated the gas chemistry in 2010–2011. This explanation reliably justifies the observed geochemical data, although the mechanisms leading to the change in time of the dominating magmatic fluid source are not clear. At this regard, a geophysical survey able to provide information on the location of the two magma batches could be useful to clarify the possible relationships between the compositional changes that affected the Peteroa fluid discharges and the 2010–2011 eruptive activity. Fil: Tassi, Franco. Universita Degli Studi Di Firenze; Italia Fil: Aguilera, F.. Servicio Nacional de Geología y Minería; Chile Fil: Benavente, O.. Universidad de Chile; Chile Fil: Paonita, A.. Istituto Nazionale Di Geofisica E Vulcanologia; Italia Fil: Chiodini, Giovanni. Istituto Nazionale Di Geofisica E Vulcanologia; Italia Fil: Caliro, S.. Istituto Nazionale Di Geofisica E Vulcanologia; Italia Fil: Agusto, Mariano Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina Fil: Gutierrez, F.. Universidad de Chile; Chile. Advanced Mining Technology Center; Chile Fil: Capaccioni, B.. Department of Earth and Geological -Environmental Science; Italia Fil: Vaselli, O.. Universita Degli Studi Di Firenze; Italia Fil: Caselli, Alberto Tomás. Universidad Nacional de Rio Negro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Saltori, O.. Universidad de Chile; Chile

Lascar (5592 m a.s.l.) and Lastarria (5697 m a.s.l.) are Chilean active stratovolcanoes located in the Central Volcanic Zone (CVZ; 16°S to 28°S) that have developed on top of a 71 km thick continental crust. Independently of the similarities in their Plinian/Vulcanian eruptive styles, their complex magmatic feeding structures and the origins of their magmatic fluids still necessitate constraints in order to improve the reliability of geochemical monitoring. Here we investigate the petrography, bulk-rock chemistry, and mineral chemistry in products from the 1986–1993 explosive eruptive cycle at Lascar and from several Holocene eruptive sequences at Lastarria. These data are integrated with measurements of the noble gas isotopes in fluid inclusions (FIs) of minerals from the same products as well as in fumarole gases. The geochemistry of minerals and rocks shows that the studied products belong to high-K–calc-alkaline series typical of subduction-related settings, and provide evidence of differentiation, mixing, and crustal assimilation that are higher at Lastarria. The contribution of slab sediments and fluids to magma genesis in the wedge is limited, suggesting a homogeneous mantle beneath CVZ. The deepest crystallization processes occurred at variable levels of the plumbing systems according to the lithostatic equivalent depths estimated with mineral equilibrium geobarometers at Lascar (15–29 km) and Lastarria (~20–40 km). The 40Ar/36Ar and 4He/20Ne ratios in FIs and fumarole gases indicate the presence of some degree of air contamination in the fluids from both volcanoes. The 3He/4He values at Lascar (6.9–7.3 Ra) are relatively homogeneous and comparable to those of fumaroles, suggesting a main zone of magma crystallization and degassing. In contrast, the 3He/4He values at Lastarria (5.31–8.01 Ra) vary over a wide range, suggesting various magma storage levels and providing evidence of crustal contamination, as indicated by the rock chemistry. We argue that mantle beneath the two volcanoes has a MORB-like signature of 3He/4He, while local crustal contamination explains the lower ratios measured at Lascar.

This work presents chemical and isotopic (δ13C-CO2, δ13C-CH4 3He, 4He, 20Ne, 40Ar, 36Ar, δ18O and δD) data of fluid discharges from Colpitas-Taapaca volcanic-hydrothermal system, located close to the Taapaca Volcanic Complex, with the aim to investigate the physical-chemical conditions of the fluid source and to provide a preliminary evaluation of the geothermic potential of the study area. Colpitas thermal springs (to 56 °C) and part of the cold springs (≤18°C) from this area have a Na+-Cl- composition and Total Dissolved Solids (TDS) values (from 6,059 to 19,118 mg/L). Putre springs also show a Na+-Cl- composition, TDS values up to 7,887 mg/L, and outlet temperatures from 21 to 31 °C. Colpitas cold springs, with a Ca2+-SO42- composition and relatively low TDS values (≤1,350 mg/L), are likely produced by interaction of shallow water with uprising H2S-rich hydrothermal gases. This process is likely also controlling the chemistry of Jurase thermal springs, which have the highest outlet temperatures of the study area (up to 68 °C), a Ca2+-SO42- composition and TDS values ≤2,355 mg/L. Eventually, Las Cuevas springs have temperatures up to 36 °C, a Na+-HCO3- composition and low TDS values (≤1,067 mg/L), typical features of springs related to a shallow aquifer. The δ18OH2O and δD-H2O values indicate that all waters have a dominant meteoric origin. Enrichments in 18O and D shown by Colpitas and Putre thermal waters are likely due to steam loss and water-rock interaction, masking a possible direct steam contribution from magmatic degassing. Gas emissions from Colpitas bubbling pools are dominated by CO2, with significant concentrations of CH4, H2S and H2. The Rc/Ra values (up to 2.04) of Colpitas gases indicate a significant contribution of magmatic to mantle He, whereas the high CO2/3He ratios, combined with d13C-CO2 values ranging from -7.66 to -5.63 % vs. PDB, imply a dominant crustal CO2 source, mostly involving limestone. Estimated temperatures based on the composition of waters and gases from Colpitas are up to 215 °C. Higher temperatures (240 °C) are estimated for Putre thermal waters, although these waters, as well as those from Jurase and Las Cuevas, are too immature for a reliable application of geothermometric techniques. Based on the theoretical reservoir temperature and the measured Cl total output, the thermal energy released from Colpitas thermal area is estimated at up to 13.9 Mw. Such results suggest the occurrence of a promising heat source, possibly related to Taapaca volcanic complex, and encourage the development of future research based on combined geophysical and ccepted geochemical approaches, in order to provide a reliable evaluation of the geothermal potential of the whole area.

Recent geophysical evidence for large-scale regional crustal inflation and localized crustal magma intrusion has made Lastarria volcano (northern Chile) the target of numerous geological, geophysical, and geochemical studies. The chemical composition of volcanic gases sampled during discrete campaigns from Lastarria volcano indicated a well-developed hydrothermal system from direct fumarole samples in A.D. 2006, 2008, and 2009, and shallow magma degassing using measurements from in situ plume sampling techniques in 2012. It is unclear if the differences in measured gas compositions and resulting interpretations were due to artifacts of the different sampling methods employed, short-term excursions from baseline due to localized changes in stress, or a systematic change in Lastarria's magmatic-hydrothermal system between 2009 and 2012. Integrated results from a two-day volcanic gas sampling and measurement campaign during the 2014 International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) Commission on the Chemistry of Volcanic Gases (CCVG) 12th Gas Workshop are used here to compare and evaluate current gas sampling and measurement techniques, refine the existing subsurface models for Lastarria volcano, and provide new constraints on its magmatic-hydrothermal system and total degassing budget. While compositional differences among sampling methods are present, distinct compositional changes are observed, which if representative of longterm trends, indicate a change in Lastarria's overall magmatic-hydrothermal system. The composition of volcanic gases measured in 2014 contained high proportions of relatively magma- and water-soluble gases consistent with degassing of shallow magma, and in agreement with the 2012 gas composition. When compared with gas compositions measured in 2006-2009, higher relative H2O/CO2 ratios combined with lower relative CO2/St and H2O/St and stable HCl/St ratios (where St is total S [SO2 + H2S]) are observed in 2012 and 2014. These compositional changes suggest variations in the magmatic-hydrothermal system between 2009 and 2012, with possible scenarios to explain these trends including: (1) decompression-induced degassing due to magma ascent within the shallow crust; (2) crystallization-induced degassing of a stalled magma body; (3) depletion of the hydrothermal system due to heating, changes in local stress, and/or minimal precipitation; and/or (4) acidification of the hydrothermal system. These scenarios are evaluated and compared against the geophysical observations of continuous shallow inflation at ~8 km depth between 1997 and 2016, and near-surface ( < 1 km) inflation between 2000 and 2008, to further refine the existing subsurface models. Higher relative H2O/CO2 observed in 2012 and 2014 is not consistent with the depletion or acidification of a hydrothermal system, while all other observations are consistent with the four proposed models. Based on these observations, we find that scenarios 1 or 2 are the most likely to explain the geochemical and geophysical observations, and propose that targeted shallow interferometric synthetic-aperture radar (InSAR) studies could help discriminate between these two scenarios. Lastly, we use an average SO2 flux of 604 ± 296 t/d measured on 22 November 2014, along with the average gas composition and diffuse soil CO2 flux measurements, to estimate a total volatile flux from Lastarria volcano in 2014 of ~12,400 t/d, which is similar to previous estimates from 2012.

The Principal Cordillera of Central Chile is characterized by two belts of different ages and lithologies: (i) an eastern Mesozoic belt, consisting of limestone- and gypsum-rich sedimentary rocks at the border between Central Chile and Argentina, where the active volcanic arc occurs; and (ii) a western belt of Cenozoic age containing basaltic to andesitic volcanic and volcanoclastic sequences. This distinctive geological setting controls water chemistry of cold and thermal springs in the region, which are fed by meteoric water that circulates through deep regional structures. In the western sector of Principal Cordillera, water–rock interaction processes produce low TDS, slightly alkaline HCO3− dominated waters, although dissolution of underlying Mesozoic evaporitic rocks occasionally causes SO42 − and Cl− enrichments. In this area, few Na+–HCO3− and Na+–SO42 − waters occurred, being likely produced by a Ca2 +–Na+ exchange during water–rock interactions. Differently, the chemical features of Ca2 +–Cl− waters was likely related to an albitization–chloritization process affecting basaltic to andesitic rocks outcropping in this area. Addition of Na+–Cl− brines uprising from the eastern sector through the west-verging thrust faults cannot be excluded, as suggested by the occurrence of mantle He (~ 19%) in dissolved gases. In contrast, in the eastern sector of the study region, mainly characterized by the occurrence of evaporitic sequences and relatively high heat flow, mature Na+–Cl− waters were recognized, the latter being likely related to promising geothermal reservoirs, as supported by the chemical composition of the associated bubbling and fumarolic gases. Their relatively low 3He/4He ratios (up to 3.9 Ra) measured in the fumaroles on this area evidenced a significant crustal contamination by radiogenic 4He. The latter was likely due to (i) degassing from 4He-rich magma batches residing in the crust, and/or (ii) addition of fluids interacting with sedimentary rocks. This interpretation is consistent with the measured δ13C-CO2 values (from − 13.2 to − 5.72‰ vs. V-PDB) and the CO2/3He ratios (up to 14.6 × 1010), which suggest that CO2 mostly originates from the limestone-rich basement and recycling of subducted sediments, with an important addition of sedimentary (organic-derived) carbon, whereas mantle degassing contributes at a minor extent. According to geothermometric estimations based on the Na+, K+, Mg2 + and Ca2 + contents, the mature Na+–Cl− rich waters approached a chemical equilibrium with calcite, dolomite, anhydrite, fluorite, albite, K-feldspar and Ca- and Mg-saponites at a broad range of temperatures (up to ~ 300 °C) In the associated gas phase, equilibria of chemical reactions characterized by slow kinetics (e.g. sabatier reaction) suggested significant contributions from hot and oxidizing magmatic gases. This hypothesis is consistent with the δ13C-CO2, Rc/Ra, CO2/3He values of the fumarolic gases. Accordingly, the isotopic signatures of the fumarolic steam is similar to that of fluids discharged from the summit craters of the two active volcanoes in the study area (Tupungatito and Planchon–Peteroa). These results encourage the development of further geochemical and geophysical surveys aimed to provide an exhaustive evaluation of the geothermal potential of these volcanic–hydrothermal systems.