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A hydrogeological study of the shallowest part of the halite nucleus of the Salar de Atacama is presented, focusing on the isotopic variability in δ18O and δ2H (SMOW) in the brine. It is observed that intensive brine extraction has induced upward vertical flows from the lower aquifer, which presents with a lighter isotopic composition (δ18O: −0.87‰ to −2.49‰; δ2H: −26.04‰ to −33.25‰), toward the upper aquifer, which has more variable and enriched isotopic values. Among the possible explanations for the lighter isotopic composition of the lower aquifer waters is the influence of paleolakes formed during the wetter periods of the Late Pleistocene and Holocene that recharged the underlying aquifers. The geological structure of the Salar, including faults and the distribution of low-permeability layers, has played a determining role in the system's hydrodynamics. This study emphasizes the need for continuous and detailed monitoring of the isotopic composition to assess the sustainability of the water resource in response to brine extraction and future climate changes. Additionally, it suggests applying this methodology to other salt flats in the region for a better understanding of hydrogeological processes in arid zones. The research provides an integrative view of the relationship between resource extraction, water management, and ecosystem conservation in one of the most important salars in the world. [ABSTRACT FROM AUTHOR]

Las problematizaciones académicas sobre la identidad son un insumo clave para analizar las dinámicas de la etnicidad en el campo sociopolítico lickanantay actual. A partir de lo anterior, abordamos mediante un caso de estudio el intento de ciertos subgrupos de desmembrarse de su unidad sociopolítica mayor a partir de acciones que buscan obtener validación mediante la puesta en diálogo entre el saber local y el académico. El subgrupo pone así en tensión las relaciones con la comunidad mayor de pertenencia y logra, al menos, mejorar su posición dentro de ella.

A hydrogeological study of the shallowest part of the halite nucleus of the Salar de Atacama is presented, focusing on the isotopic variability in δ18O and δ2H (SMOW) in the brine. It is observed that intensive brine extraction has induced upward vertical flows from the lower aquifer, which presents with a lighter isotopic composition (δ18O: −0.87‰ to −2.49‰; δ2H: −26.04‰ to −33.25‰), toward the upper aquifer, which has more variable and enriched isotopic values. Among the possible explanations for the lighter isotopic composition of the lower aquifer waters is the influence of paleolakes formed during the wetter periods of the Late Pleistocene and Holocene that recharged the underlying aquifers. The geological structure of the Salar, including faults and the distribution of low-permeability layers, has played a determining role in the system’s hydrodynamics. This study emphasizes the need for continuous and detailed monitoring of the isotopic composition to assess the sustainability of the water resource in response to brine extraction and future climate changes. Additionally, it suggests applying this methodology to other salt flats in the region for a better understanding of hydrogeological processes in arid zones. The research provides an integrative view of the relationship between resource extraction, water management, and ecosystem conservation in one of the most important salars in the world.

Copyright of Runa: Archivo para las Ciencias del Hombre is the property of Runa: Archivo para las Ciencias del Hombre and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Habiendo vivido junto al dinamismo geológico de la cuenca del Salar de Atacama (Chile) por milenios, el pueblo Lickanantay ha acumulado abundantes datos observacionales y ceremoniales acerca de la naturaleza volcánica que les rodea y la participación de volcanes en procesos más amplios de formación cosmoecológica. Sin embargo, la vulcanológica formal no ha establecido un diálogo sustantivo con estos conocimientos. A través de una colaboración intercultural, este artículo expone lo que llamamos ‘vulcanología Lickanantay’ —o el sistema Lickanantay de conocimiento sobre volcanes, relaciones volcanes-humanos e interdependencia geocósmica— con el objetivo de hacerla disponible para la comunidad vulcanológica general. Primero, describimos las características básicas de la vulcanología Lickanantay. Luego nos enfocamos en el campo geotérmico de El Tatio para ofrecer una aproximación situada. Finalmente, delineamos algunos elementos para la gestión del riesgo volcánico desde una perspectiva Lickanantay. En nuestras conclusiones sugerimos que la vulcanología Lickanantay invita a pensar lo ‘indígena’ no como un conjunto finito de conocimientos y prácticas sino como una demanda por autonomía territorial y epistemológica, y que es sólo reconociendo esa demanda que la vulcanología podrá responder al llamado de la descolonización de la ciencia.

InSAR coherence-change detection (CCD) is a promising remote sensing technique that is able to map areas affected by torrential sediment transport triggered by flash floods in arid environments. CCD maps the changes in the interferometric coherence between synthetic aperture radar images (InSAR coherence), a parameter that measures the stability of the radar signal between two different SAR images, i.e., data acquisitions. In arid environments, such changes are mainly due to changes in the surface. However, the residual effect of other factors on the InSAR coherence cannot be completely excluded. Therefore, CCD-based maps contain the uncertainty of whether the detected changes are actual changes in the observed surface or just errors related to those residual effects. Thus, in this paper, the results of four CCD mapping methods, with different degrees of complexity and sensitivity to the different factors affecting the InSAR coherence, are compared in order to evaluate the existence of the errors and their importance. The obtained CCD maps are also compared with changes in satellite optical images and a field campaign. The results lead to the conclusion that CCD maps are reliable in the identification of the zones affected by sediment transport, although the precision in the delimitation of the affected area remains an open issue. However, highly rugged relief areas still require a thorough analysis of the results in order to discard the geometric effects related to the perpendicular baseline. [ABSTRACT FROM AUTHOR]

Copyright of REDER: Revista de Estudios Latinoamericanos sobre Reducción del Riesgo de Desastres is the property of Corporacion Gestion de Riesgos y Desastres (GRID-Chile) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Coherence change detection (CCD) is a remote sensing technique used to map phenomena that, under certain conditions, can be directly related to changes in Interferometric SAR (InSAR) coherence. Mapping the areas affected by sediment transport events in arid environments is one of the most common applications of CCD. However, the reliability of these maps remains an unsolved issue. This paper focuses on verifying that InSAR coherence is indeed able to detect all the fluvial sediment transport events that have actually mobilised sediments in arid environments by building a classification model and validating its results. The proposed methodology is tested in three study areas in Salar de Atacama, Chile, using three years of Sentinel data plus a fourth year for validation, and meteorological records of rainfall, the relative humidity of the air and snow cover. The results prove that InSAR coherence can be used to remotely detect sediment transport events related to flash floods in arid environments, that it might have a greater detection ability than meteorological records and that the perpendicular baseline does have a relevant effect on the InSAR coherence that needs to be considered. All these findings will increase the reliability of maps based on InSAR coherence. In addition, the proposed method will allow focusing the mapping tasks only on the relevant dates and, once calibrated, the classification model will enable the automatised remote detection of new events. [ABSTRACT FROM AUTHOR]

ABSTRACT The lacustrine systems of La Brava and La Punta, located in the Tilopozo sector in the extreme south of Salar de Atacama, are pristine high-altitude Andean lakes found along the central Andes of South America. This shallow ecosystem suffers from permanent evaporation, leading to falling water levels, causing it to recede or disappear during the dry season. This dynamic causes physicochemical changes in lakes, such as low nutrient availability, pH change, and dissolved metals, which can influence the composition of the microbial community. In this study, we used a metataxonomic approach (16S rRNA hypervariable regions V3 to V4) to characterize the sedimentary microbiota of these lakes. To understand how the water column affects and is structured in the microbiota of these lakes, we combined the analysis of the persistence of the water column through satellite images and physicochemical characterization. Our results show a significant difference in abiotic factors and microbiota composition between La Punta and La Brava lakes. In addition, microbiota analysis revealed compositional changes in the ecological disaggregation (main and isolated bodies) and antagonistic changes in the abundance of certain taxa between lakes. These findings are an invaluable resource for understanding the microbiological diversity of high Andean lakes using a multidisciplinary approach that evaluates the microbiota behavior in response to abiotic factors. IMPORTANCE In this study, we analyzed the persistence of the water column through satellite images and physicochemical characterization to investigate the composition and diversity in High Andean Lake Systems in a hyperarid environment. In addition to the persistence of the water column, this approach can be used to analyze changes in the morphology of saline accumulations and persistence of snow or ice; for example, for establishing variable plant cover over time and evaluating the microbiota associated with soils with seasonal changes in plants. This makes it an ideal approach to search for novel extremophilic microorganisms with unique properties. In our case, it was used to study microorganisms capable of resisting desiccation and water restriction for a considerable period and adapting to survive in ecological niches, such as those with high UV irradiation, extreme drought, and high salt concentration.

Copyright of Revista Austral de Ciencias Sociales is the property of Facultad de Filosofia y Humanidades, Intituto de Ciencias Sociales, Universidad Austral de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The land snail Megalobulimus spp. has been frequently recorded in prehispanic cemeteries in the oases of San Pedro de Atacama, Chile, despite the fact that it is not native to this region. It lives in the humid and tropical environment of northwestern Argentina, for which reason, when it is found outside its native habitat, its presence is taken as an indicator of long-distance exchange. Archaeologists posit that its function was to hold color pigments. In this multidisciplinary study we analyze the snail's presence in funerary contexts, complementing this with a taxonomic analysis of archaeological specimens and a review of biological-ethological data of said gastropod. We present unpublished data regarding the use of Megalobulimus in the Atacama, while providing new information about its connection to the practice of inhaling psychoactive substances. We conclude that its function as a container of pigments, carbonates, or hallucinogens stems from its symbolic meaning as part of the vital renewal through the fertilizing water of the earth. This symbolism explains the role that Megalobulimus played in the ritual exchange networks of the Circumpuneña area and, by extension, the Central-South Andes. [ABSTRACT FROM AUTHOR]

Substantial knowledge has accumulated on the microbiome of the hyperarid Atacama Desert during the last two decades; however, information on Atacama free-living amoebae (FLA) is limited and increasing efforts are required. FLA are polyphyletic heterotrophic naked or testate protists that feed on organic matter, fungi, protozoa, and bacteria and may disseminate infections. Amoebae in Chile are represented by 416 taxa and 64 genera, and 29 taxa have been identified in arid shrub lands at the southern limit of the Atacama Desert, and Acanthamoeba are present in all the country's regions. To expand our knowledge and to contribute to the biogeographic distribution of Atacama FLA, we report the dominant presence of members of the genus Acanthamoeba in water and sediment sampled at the Loa and Salado rivers in the pre-Andean zone of the Antofagasta Region, northern Chile, at sites 2500 m above sea level. We expect these observations and preliminary evidence of FLA presence in other wetlands (Chiuchiu, Tebenquiche) in this region to be incentive for further exploration of Atacama amoebae. [ABSTRACT FROM AUTHOR]

The Salar de Atacama in northern Chile hosts the biggest lithium reserves globally. However, concerns have arisen regarding the environmental impact of lithium extraction on its basin; in particular, the possible drought of its lagoons that sustain unique natural ecosystems. This investigation implemented an image processing and statistical methodology to assess the area evolution and dynamic behavior of these main water bodies between 1986 and 2018. Results showed that these lagoon systems have not presented significant changes despite increasing lithium production, even for the years of large brine extraction. The analysis indicated that the total surface area of the lagoons varied within a restricted range at 95% confidence level: on average, of the total area covered by these systems 0.03% could have been lost or 0.01% could have been gained per year. Moreover, a multivariate analysis indicated that brine extraction did not have a negative impact on the evolution of the surface areas of the lagoons during the last three decades. [ABSTRACT FROM AUTHOR]

ABSTRACT Salar de Atacama is located approximately 55 km south of San Pedro de Atacama in the Antofagasta region, Chile. The high UV irradiation and salt concentration and extreme drought make Salar de Atacama an ideal site to search for novel soil microorganisms with unique properties. Here, we used a metataxonomic approach (16S rRNA V3-V4) to identify and characterize the soil microbiota associated with different surface azonal vegetation formations, including strict hygrophiles (Baccharis juncea, Juncus balticus, and Schoenoplectus americanus), transitional hygrophiles (Distichlis spicata, Lycium humile, and Tessaria absinthioides), and their various combinations. We detected compositional differences among the soil surface microbiota associated with each plant formation in the sampling area. There were changes in soil microbial phylogenetic diversity from the strict to the transitional hygrophiles. Moreover, we found alterations in the abundance of bacterial phyla and genera. Halobacteriota and Actinobacteriota might have facilitated water uptake by the transitional hygrophiles. Our findings helped to elucidate the microbiota of Salar de Atacama and associate them with the strict and transitional hygrophiles indigenous to the region. These findings could be highly relevant to future research on the symbiotic relationships between microbiota and salt-tolerant plants in the face of climate change-induced desertification. IMPORTANCE The study of the composition and diversity of the wetland soil microbiota associated with hygrophilous plants in a desert ecosystem of the high Puna in northern Chile makes it an ideal approach to search for novel extremophilic microorganisms with unique properties. These microorganisms are adapted to survive in ecological niches, such as those with high UV irradiation, extreme drought, and high salt concentration; they can be applied in various fields, such as biotechnology and astrobiology, and industries, including the pharmaceutical, food, agricultural, biofuel, cosmetic, and textile industries. These microorganisms can also be used for ecological conservation and restoration. Extreme ecosystems are a unique biological resource and biodiversity hot spots that play a crucial role in maintaining environmental sustainability. The findings could be highly relevant to future research on the symbiotic relationships between microbiota and extreme-environment-tolerant plants in the face of climate change-induced desertification.

Understanding groundwater flow involves characterizing the spatial variability of aquifer attributes and possible hydraulic connectivity structures. The latter are of crucial importance because high permeability channels may control groundwater flow and contaminant transport. In evaporitic aquifer systems, these preferential channels can consist of karst conduits, developed at different scales, as well as fault zones. These features condition the economic development of salt flats at the Central Andes. Hydraulic connectivity may affect exploitation efficiency by enhancing the inflow of less evaporated brine thus diminishing its mineral content (i.e., concentration of Li and K). In this context, we investigate if it is possible to use (tomographic) stochastic inversion (regularized pilot point method) in order to characterize the presence of connectivity structures in an evaporitic aquifer of great extension (some 1,500 km2) from head response measured at numerous observation points during a year long sequence of three hydraulic tests. Results show that, even though the solution is nonunique, the main preferential flow zones are identified. Numerous inversions yield similar fits to observed drawdowns with maximum errors of few centimeters. Preferential flow is identified not only by elongated high permeability regions, but also by a marked scale effect (model transmissivities are some 30 times larger than their local tests counterparts). The main high conductivity zones are consistent with independent information based on geophysics, isotopes, mixing ratios, piezometric data, and the expected dissolution processes. Key Points: A hydraulic test is carried out and monitored in many observation points to assess heterogeneity over a tens of kilometers karst aquiferStochastic inversion allows us to identify preferential flow paths, which are consistent with independent dataA marked scale effect is observed, suggesting that karst structures control large scale permeability [ABSTRACT FROM AUTHOR]

The need of establishing more substantive dialogs between the mainstream and Indigenous knowledge on volcanoes has been increasingly recognized. To contribute to this endeavor, in this article we present the basic volcanological understandings of the Lickanantay people in the Salar de Atacama Basin. The Salar de Atacama Basin is an active volcanic territory within the Central Volcanic Zone of the Andes (CVZA). From the El Tatio geothermal field to Socompa volcano, more than 19 active volcanoes surround the territory that the Lickanantay (Atacameño) people have inhabited for more than 11,000 years. Living around and with the geological dynamism of the CVZA for millennia, the Lickanantay communities have accumulated rich observational and ceremonial data on volcanoes and volcanism. Paradoxically, however, while the Atacameño people have thoroughly characterized the CVZA, the volcanology community has not been properly introduced to the ancestral knowledge articulated in the territory. In order to make traditional Atacameño perspectives on volcanoes, volcanic risk, and geo-cosmic interdependence more amply available to the volcanology community, in this article, we present a basic description of what we call Atacameño volcanology. By Atacameño volcanology, we understand the ancestral principles by which volcanoes are known and understood as partaking in larger processes of a cosmo-ecological formation. Specifically, we describe the basic volcanological notions arising from the Lickanantay ancestral knowledge—volcanic formation, functions, and behavior. Second, we focus on the El Tatio geothermal field to offer a situated example. Finally, we delineate some relevant elements of human–volcano interactions and volcanic risk management from an Atacameño perspective. In our conclusions we suggest that volcanology, particularly in the context of the Andes, needs to engage more substantially with the Atacameño or other ancestral systems of knowledge production to expand volcanological insights and respond to the call for decolonizing science.

Godofredo Enes Pereira, Christina Leigh Geros and Jon Goodbun have been analysing governmental Green New Deal policy globally, viewing it through the microcosmic eye of their own research and that of their students on the MA Environmental Architecture course at the Royal College of Art in London. This includes their Lithium Triangle project that concentrates on the environmental damage caused by the extraction of lithium from the Chilean landscape, and the Orang‐orang and the Hutan project in Indonesia that contests Western dominance and the effects of centuries of colonisation. [ABSTRACT FROM AUTHOR]

The lacustrine systems of La Brava and La Punta, located in the Tilopozo sector in the extreme south of Salar de Atacama, are pristine high-altitude Andean lakes found along the central Andes of South America. This shallow ecosystem suffers from permanent evaporation, leading to falling water levels, causing it to recede or disappear during the dry season. This dynamic causes physicochemical changes in lakes, such as low nutrient availability, pH change, and dissolved metals, which can influence the composition of the microbial community. In this study, we used a metataxonomic approach (16S rRNA hypervariable regions V3 to V4) to characterize the sedimentary microbiota of these lakes. To understand how the water column affects and is structured in the microbiota of these lakes, we combined the analysis of the persistence of the water column through satellite images and physicochemical characterization. Our results show a significant difference in abiotic factors and microbiota composition between La Punta and La Brava lakes. In addition, microbiota analysis revealed compositional changes in the ecological disaggregation (main and isolated bodies) and antagonistic changes in the abundance of certain taxa between lakes. These findings are an invaluable resource for understanding the microbiological diversity of high Andean lakes using a multidisciplinary approach that evaluates the microbiota behavior in response to abiotic factors. IMPORTANCE In this study, we analyzed the persistence of the water column through satellite images and physicochemical characterization to investigate the composition and diversity in High Andean Lake Systems in a hyperarid environment. In addition to the persistence of the water column, this approach can be used to analyze changes in the morphology of saline accumulations and persistence of snow or ice; for example, for establishing variable plant cover over time and evaluating the microbiota associated with soils with seasonal changes in plants. This makes it an ideal approach to search for novel extremophilic microorganisms with unique properties. In our case, it was used to study microorganisms capable of resisting desiccation and water restriction for a considerable period and adapting to survive in ecological niches, such as those with high UV irradiation, extreme drought, and high salt concentration., Competing Interests: The authors declare no conflict of interest.

Wormholes are highly conductive channels that develop in high solubility rocks. They are especially important for environmental and industrial sustainability in saline karst aquifers (e.g. Salar de Uyuni, Salar de Atacama). Wormholes dynamics (i.e., the space and time evolution of these preferential flow paths) depends on the hydrodynamic and geochemical conditions during formation, as well as on wormholes competition for flow. Despite the importance of wormholes interaction for their development, experimental efforts have focused on the evolution of a single flow-path. Direct observation and quantification of wormholes dynamics is still lacking. We propose an experimental set-up to visualize and characterize the dynamics of multiple wormholes, which may help to understand the changes in flow and transport behaviour of aquifers. We performed a dissolution experiment in a 2D synthetic evaporitic aquifer, and simultaneous fluorescent tracer tests before and during wormhole growth. We visualized the growth by sequential photographs, with the fluorescent tracer highlighting the evolving structures. We quantified wormholes dynamics by measuring pressure and mass changes of the aquifer, and by image analysis. On the one hand, results show that wormholes tend to form along areas where flux was fastest prior to dissolution. They also show clear evidence of competition for water between wormholes and represent the first quantitative evidence of the amplifying factor that drives the self-organization in wormhole growth. On the other hand, we found that the competition is slower than predicted by current analytical and numerical theories, but consistent with other laboratory results. We conjecture that the discrepancy between theory and experiments can be attributed to the combined effect of non-linear kinetics and particle dragging during dissolution. We then compared experimental tracer breakthrough curves before and during the formation of preferential flow paths. They reflect wormhole growth by an accentuated non-Fickian behaviour, with reduced first arrival and increased tailing., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Daniel Fernandez Garcia reports financial support was provided by SQM SA., (Copyright © 2022. Published by Elsevier B.V.)

The Atacama region in Northern Chile hosts the driest desert on Earth and provides the second highest global Li production, containing the largest reported lithium reserves in the world. The occurrence of extremely elevated Li concentration is restricted to brine deposits contained in the halite nucleus of the Salar de Atacama (SDA). The origin of Li and other solutes in the Andean salt flats has been attributed to different processes, where weathering of Neogene and Quaternary volcanic rocks has been considered to be the most important. Despite recent advances, there is still limited geochemical and isotopic Li data in ignimbrites, particularly surrounding the SDA, hence the potential of these units as a source has remained elusive. In this study, we provide new Li concentration and isotopic data in ignimbrites from the Western Cordillera, fine sediments from the marginal zone of the SDA, and suspended load in shallow groundwater. A moderate enrichment (between 20 and 50 ppm) is recorded in volcanic rocks, averaging 33 ppm, while fine sediments present Li contents one order of magnitude higher, with a mean concentration of ~290 ppm. Due to the Li contents recorded in ignimbrites, which is slightly higher than the upper crust average (24–30 ppm; Rudnick and Gao, 2004), we propose that the potential of these units as the main source of Li resides in their large areal extent, volume, and hydraulic gradient with respect to the SDA. The δ7Li values in ignimbrites vary from −1.5 ‰ to +12.8 ‰. In contrast, marginal zone sediments show negative values of δ7Li (from −1.9 ‰ to −5.3 ‰), except for fine sediments from the Peine Block where a δ7Li is +4.4 ‰. Our results reveal that the measured δ7Li in ignimbrites would indicate volatile exsolution as the main syn -eruptive factor controlling the isotope Li distribution. Regarding post-eruptive processes, water-rock interactions trigger partition of 7Li from ignimbrite to water. Both syn -eruptive and post-eruptive proposed were tested by numerical modeling, supporting our interpretation. We propose that the predominant constituent in ignimbrites, crystals or glass, impacts the subsequent distribution and fractionation of Li in inflowing waters and fine sediments covering the marginal zone. The analysis presented here allows us to define three subzones where different processes are controlling Li fractionation. These factors together with the geological, hydrologic, and climatic history of the region have led to the world-renowned accumulation of Li in the SDA. [Display omitted] • The potential of ignimbrites as a source of Li resides in their volume and key location. • The δ7Li values in ignimbrites surrounding the SDA range between −1.5 ‰ and +12.8 ‰. • The crystallinity degree in ignimbrites impacts the Li distribution and isotopic fractionation. • Based on geochemical and isotopic Li distribution, the SDA can be divided in three subzones. [ABSTRACT FROM AUTHOR]

Salar de Atacama is located approximately 55 km south of San Pedro de Atacama in the Antofagasta region, Chile. The high UV irradiation and salt concentration and extreme drought make Salar de Atacama an ideal site to search for novel soil microorganisms with unique properties. Here, we used a metataxonomic approach (16S rRNA V3-V4) to identify and characterize the soil microbiota associated with different surface azonal vegetation formations, including strict hygrophiles (Baccharis juncea, Juncus balticus, and Schoenoplectus americanus), transitional hygrophiles (Distichlis spicata, Lycium humile, and Tessaria absinthioides), and their various combinations. We detected compositional differences among the soil surface microbiota associated with each plant formation in the sampling area. There were changes in soil microbial phylogenetic diversity from the strict to the transitional hygrophiles. Moreover, we found alterations in the abundance of bacterial phyla and genera. Halobacteriota and Actinobacteriota might have facilitated water uptake by the transitional hygrophiles. Our findings helped to elucidate the microbiota of Salar de Atacama and associate them with the strict and transitional hygrophiles indigenous to the region. These findings could be highly relevant to future research on the symbiotic relationships between microbiota and salt-tolerant plants in the face of climate change-induced desertification. IMPORTANCE The study of the composition and diversity of the wetland soil microbiota associated with hygrophilous plants in a desert ecosystem of the high Puna in northern Chile makes it an ideal approach to search for novel extremophilic microorganisms with unique properties. These microorganisms are adapted to survive in ecological niches, such as those with high UV irradiation, extreme drought, and high salt concentration; they can be applied in various fields, such as biotechnology and astrobiology, and industries, including the pharmaceutical, food, agricultural, biofuel, cosmetic, and textile industries. These microorganisms can also be used for ecological conservation and restoration. Extreme ecosystems are a unique biological resource and biodiversity hot spots that play a crucial role in maintaining environmental sustainability. The findings could be highly relevant to future research on the symbiotic relationships between microbiota and extreme-environment-tolerant plants in the face of climate change-induced desertification.

We investigated the role of pre-existing basement normal faults, and ductile layers present within post-rift sequences on the final geometry and kinematics of hybrid (thick and thin-skinned) fold and thrust belts that result of tectonic inversion, using as an example the northern region of the Salar de Atacama Basin in the Central Andes. The study was developed integrating field data consisting of regional and local observations and geological mapping, and the seismic and structural interpretation of 2-D industrial seismic profiles to understand the current structure of the basin. A regional-scale balanced cross-section was constructed and restored to validate our interpretations and determine the pre-shortening tectonic configuration of the basin. Our results suggest that low angle normal faults result in favorable structures for the development of thick-skinned thrust ramps from their full tectonic inversion during the growth of fold and thrust belts. In the Salar de Atacama Basin, these structures allowed for the uplift and exhumation of large Paleozoic stratified and crystalline rock on its western section. The existence of ductile strata within post-rift sequences commonly facilitates the transition from thick to thin-skinned structural style during the progressive tectonic inversion of pre-existing half-graben structures. This mechanism allowed for the creation of prominent east-verging basement cored anticlines and doubly verging and narrow, shallow thin-skinned folds and thrusts at the northernmost part of the Salar de Atacama Basin. Pieces of evidence from the basin suggest that the initial areal extension (length) of the post-rift ductile strata exert a fundamental role in the lateral extension of thin-skinned thrusts. Finally, the existence or not of important ductile strata in the overburden stratigraphy conditions the progression of hybrid fold and thrust belts after pre-existing normal faults are reactivated. • Thick and thin-skinned fold-and-thrust belt. • The Salar de Atacama Basin. • Full reverse-reactivation of basement normal faults produce kilometric-scale thrust ramps. • Post-rift evaporites control the shallow thin-skinned deformation during contraction of pre-existing rift-related normal faults. [ABSTRACT FROM AUTHOR]

With the development of light and rechargeable batteries for electric vehicles, global demand for lithium has increased considerably in recent years. This has drawn more attention to how lithium is produced, especially on primary extraction operations such as those at the Salar de Atacama in Northern Chile. There are concerns that brine extraction at the Atacama could irreversibly damage the basin's complex hydrological system. However, differing opinions over the definition of water have frustrated basic action measures for minimizing impacts of operations like these. Some lithium industry stakeholders have historically described brine as a mineral, while others emphasize that brine is also a type of water in a complex network of different water resources. In this communication, we show that brines are undeniably a type of water. We support this position by investigating brine's water molecular structure using molecular dynamics simulations and comparing Gibbs formation energy of the brine using thermodynamic principles. Molecular dynamics show that the structure of water molecules in brine is similar to the structure of molecules in pure water at a pressure of 1.2 atm. The analysis of Gibbs formation energy shows that more than 99% of the brine's formation energy is directly from water, not dissolved minerals. • The rapid expansion of applications of Lithium-ion batteries has raised Li demand. • Overexploitation of Li brine resources such as Salar de Atacama raised concerns. • There is an ongoing debate over the definition of Lithium brine as water or minerals. • The debate has frustrated basic measures for moving towards a sustainable operation. • Here, we used a molecular level approach to prove that the brine is a type of water. [ABSTRACT FROM AUTHOR]

• Cradle-to-gate life cycle comparison of lithium from brine and spodumene ore. • Li 2 CO 3 and LiOH•H 2 O from brine have lower life cycle GHG emissions than from ore. • Lithium source meaningfully affects lithium ion battery environmental footprints. • Fresh water consumption is lower for brine-based products than ore-based products. Life cycle analyses (LCAs) were conducted for battery-grade lithium carbonate (Li 2 CO 3) and lithium hydroxide monohydrate (LiOH•H 2 O) produced from Chilean brines (Salar de Atacama) and Australian spodumene ores. The LCA was also extended beyond the production of Li 2 CO 3 and LiOH•H 2 O to include battery cathode materials as well as full automotive traction batteries to observe the effect that the lithium production pathways had on these end products. The LCA here covers material, water, and energy flows associated with lithium acquisition; lithium concentration; production of lithium chemicals, battery cathode powders, and batteries; and associated transportation activities along the supply chain. Based on battery cathode material, the difference in lithium source represents a difference of up to 20% for NMC811 cathode greenhouse gases (GHGs) and up to 45% for NMC622 cathode GHGs. For full batteries, this represents a difference of up to 9% for NMC811 batteries and 20% for NMC622 batteries. Production of Li 2 CO 3 from brine-based resources had less life cycle GHG emissions and freshwater consumption per tonne of Li 2 CO 3 than Li 2 CO 3 from ore-based resources. And LiOH•H 2 O produced from brine-based lithium also had less life cycle GHG emissions and freshwater consumption per tonne of LiOH•H 2 O than LiOH•H 2 O from ore-based resources. [ABSTRACT FROM AUTHOR]