Browsing by Author "Taucare, Matias"

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    Groundwater resources and recharge processes in the Western Andean Front of Central Chile
    (ELSEVIER, 2020) Taucare, Matias; Daniele, Linda; Viguier, Benoit; Vallejos, Angela; Arancibia, Gloria
    In Central Chile, the increment of withdrawals together with drought conditions has exposed the poor understanding of the regional hydrogeological system. In this study, we addressed theWestern Andean Front hydrogeology by hydrogeochemical and water stable isotope analyses of 23 springs, 10 boreholes, 5 rain-collectors and 5 leaching-rocks samples at Aconcagua Basin. From the upstream to the downstream parts of the Western Andean Front, most groundwater is HCO3-Ca and results from the dissolution of anorthite, labradorite and other silicate minerals. The Hierarchical Cluster Analysis groups the samples according to its position along the Western Andean Front and supports a clear correlation between the increasing groundwater mineralization (31-1188 mu S/cm) and residence time. Through Factorial Analysis, we point that Cl, NO3, Sr and Ba concentrations are related to agriculture practices in the Central Depression. After defining the regional meteoric water line at 33 degrees S in Chile, water isotopes demonstrate the role of rain and snowmelt above similar to 2000 m asl in the recharge of groundwater. Finally, we propose an original conceptual model applicable to the entire Central Chile. During dry periods, water releases fromhigh-elevation areas infiltrate in mid-mountain gullies feeding groundwater circulation in the fractured rocks of Western Andean Front. To the downstream, mountain-block and -front processes recharge the alluvial aquifers. Irrigation canals, conducting water from Principal Cordillera, play a significant role in the recharge of Central Depression aquifers. While groundwater in the Western Andean Front has a high-quality according to different water uses, intensive agriculture practices in the Central Depression cause an increment of hazardous elements for human-health in groundwater. (C) 2020 Elsevier B.V. All rights reserved.
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    Improving school children's understanding of water scarcity with a co-produced book on groundwater in Central Chile
    (2023) Vargas-Payera, Sofia; Taucare, Matias; Pareja, Claudio; Vejar, Jessica
    Water scarcity is a critical issue worldwide, and Chile is no exception. Since 2010, Central Chile has been enduring an ongoing water crisis due to the coupled effects of a severe drought and the overuse of water resources, especially groundwater. Rural communities have been strongly impacted, mainly because wells from which drinking water is supplied show a dramatic drop in water levels, and some have even dried up. The water scarcity scenario requires the integration of actors and disciplines to increase awareness of groundwater; however, how to make this valuable element visible in society is an issue that remains open to debate. This paper describes and reflects on the process of making educational material about groundwater and water scarcity for children to promote public awareness. Based on transdisciplinary and co-designing processes, this work describes the social perceptions of groundwater among children and community leaders, as well as how scientific information and local knowledge of water scarcity could be integrated into a book for the young population. This research finds that educational projects on groundwater resources increase people's awareness of the role of this hidden resource in the water cycle. Such projects encourage the creation of grounded and contextualised materials that incorporate the knowledge and experience already present in the communities, increasing public awareness of the role of groundwater and associated water scarcity issues, thereby integrating academia and society. This approach could be a tool to lay the foundations for successfully addressing the water crisis in Chile over generations.
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    Selective reactivation of inherited fault zones driven by stress field changes: Insights from structural and paleostress analysis of the Pocuro Fault Zone, Southern Central Andes (32.8 degrees S)
    (PERGAMON-ELSEVIER SCIENCE LTD, 2022) Taucare, Matias; Roquer, Tomas; Heuser, Gert; Perez-Estay, Nicolas; Arancibia, Gloria; Yanez, Gonzalo; Viguier, Benoit; Figueroa, Ronny; Morataa, Diego; Daniele, Linda
    This study aims to explain the selective reactivation of normal faults during the Andean orogeny at the Southern Central Andes western flank. We conducted a structural mapping and paleostress field reconstruction in the regional-scale Pocuro Fault Zone (PFZ) at 32.8 degrees S. Results reveal that the architecture of the PFZ results from at least two deformation phases, each revealing an individual progressive and gradual evolution. The earliest deformation phase is recorded by two similar to NS-striking normal faults involving a 5 km wide damage zone characterized by quartz-laumontite and calcite veins that were developed under an extensional regime with a WNW-ESE-trending sigma 3-axis. The latest deformation phase is recorded by one NS-striking reverse-dextral fault with goethite-hematite syn-tectonic precipitation and two NW-striking reverse-sinistral faults. Reverse faults were developed under a compressional/transpressional regime characterised by an ENE-WSW-trending sigma 1-axis with a sigma 2-/sigma 3-axis permutation. From a geophysical data reassessment, we inferred that observed faults in the surface within the PFZ are regional-scale deep-seated structures. Considering previous geochronological data, we correlated the earliest and latest phases with the Abanico Basin extension (middle Eocene-early Miocene) and its subsequent inversion (Miocene). Given the neotectonic evidence (geomorphic markers and deformation of unconsolidated deposits), the latter phase likely remains active. Quartz-laumontite cementation of the fault core's cataclastic material promotes mechanical strengthening leading to negative feedback for the reactivation of inherited normal faults as reverse ones. Conversely, the concentration of fractures in the damage zone between the normal faults promotes mechanical weakening resulting in a preferential area for the propagation of reverse fault during the compressive/transpressional phase.