Browsing by Author "Jara, Jose Joaquin"

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    Episodic construction of the early Andean Cordillera unravelled by zircon petrochronology
    (2021) Jara, Jose Joaquin; Barra, Fernando; Reich, Martin; Leisen, Mathieu; Romero, Rurik; Morata, Diego
    The subduction of oceanic plates beneath continental lithosphere is responsible for continental growth and recycling of oceanic crust, promoting the formation of Cordilleran arcs. However, the processes that control the evolution of these Cordilleran orogenic belts, particularly during their early stages of formation, have not been fully investigated. Here we use a multi-proxy geochemical approach, based on zircon petrochronology and whole-rock analyses, to assess the early evolution of the Andes, one of the most remarkable continental arcs in the world. Our results show that magmatism in the early Andean Cordillera occurred over a period of similar to 120 million years with six distinct plutonic episodes between 215 and 94 Ma. Each episode is the result of a complex interplay between mantle, crust, slab and sediment contributions that can be traced using zircon chemistry. Overall, the magmatism evolved in response to changes in the tectonic configuration, from transtensional/extensional conditions (215-145 Ma) to a transtensional regime (138-94 Ma). We conclude that an external (tectonic) forcing model with mantle-derived inputs is responsible for the episodic plutonism in this extensional continental arc. This study highlights the use of zircon petrochronology in assessing the multimillion-year crustal scale evolution of Cordilleran arcs.
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    On the source of metals and the environmental sustainability of battery electric vehicles versus internal combustion engine vehicles: The lithium production case study
    (2022) Guzm, Juan Ignacio; Faundez, Patricio; Jara, Jose Joaquin; Retamal, Candelaria
    Several studies support that the battery electric vehicles (BEVs) are more environmentally friendly than internal combustion engine vehicles (ICEVs). However, these studies assume that one unit of metal used in the manufacturing process is a commodity in terms of its environmental footprint. In this study, estimations for water and energy consumption and carbon dioxide emissions are used as proxies of the environmental footprint variability within the production of various metals used in the automotive industry. Through these estimations, probability distribution functions are fit to assess the sustainability of BEVs and ICEVs when considering the commodities' environmental heterogeneity.Two scenarios are assessed, which considers: (1) the manufacture of vehicles, and (2) their useful life. The results show the existence of a range of potential environmental footprints for BEVs and ICEVs, depending on the footprints of the specific metals being used. Including this input's variability, when only the manufacturing process is considered, ICEVs outperform BEVs in most of the realization cases and for all the analyzed indicators. However, if their useful life is incorporated, the BEV consistently produces significantly less carbon dioxide emissions, as well as consume the same energy and more water than ICEV.A special case study for lithium is presented as it has shown to be a critical resource and a major environmental concern for BEV production. The results show that by switching lithium from pegmatite to brine, the water consumption required for manufacturing the vehicles is reduced by 0.17%, which is contrary to the common view regarding water use in brine extraction.
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    Potential copper production through 2035 in Chile
    (2020) Lagos, Gustavo; Peters, David; Lima, Marcos; Jara, Jose Joaquin
    In the long term, primary and secondary supply of refined copper satisfies demand. Numerous models exist to explain and predict demand and secondary supply; however, the projection of primary supply relies mostly on detailed knowledge of potential mining projects and on existing ore reserves and resources. Much discussion has occurred historically regarding the availability of resources and reserves for the future. Chile, being the largest copper producer, also has the largest reserves in the world; therefore, it retains its potential to be a key player in future supply. This article explores some of the most relevant resource and technological challenges that may emerge with an accelerated development of brownfield and greenfield copper mining projects in Chile through 2035, without considering economic, regulatory, and environmental constraints. A "Full Scenario" was created to accommodate these conditions and restrictions. It includes estimates of future ore reserves, copper production, plant capacity, ore grades, energy and water consumption, greenhouse gas (GHG) emissions, and generation of tailings. Maximum production would exceed 10 million tons of contained copper from 2027 to 2030, with a resulting decrease of ore grades and the growth of energy and water consumption. The growth of indirect GHG emissions through 2035 is estimated at 18.4% less than copper production growth, because all new electric energy for this scenario would be based on renewable energy. Also, all new water used by 38 out of the 42 mining projects considered would be seawater, and some of the continental water used in 2019 would cease to be used in mining.