More Like this

1. Evaluating the Potential of Rhyolitic Glass as a Lithium Source for Brine Deposits

   https://doi.org/10.5382/econgeo.4866  

   Ellis, B. S.; Szymanowski, D.; Harris, C.; Tollan, P.M.E.; Neukampf, J.; Guillong, M.; Cortes-Calderon, E. A.; Bachmann, O. (January 2022, Economic Geology)

   Abstract Lithium is an economically important element that is increasingly extracted from brines accumulated in continental basins. While a number of studies have identified silicic magmatic rocks as the ultimate source of dissolved brine lithium, the processes by which Li is mobilized remain poorly constrained. Here we focus on the potential of low-temperature, post-eruptive processes to remove Li from volcanic glass and generate Li-rich fluids. The rhyolitic glasses in this study (from the Yellowstone-Snake River Plain volcanic province in western North America) have interacted with meteoric water emplacement as revealed by textures and a variety of geochemical and isotopic signatures. Indices of glass hydration correlate with Li concentrations, suggesting Li is lost to the water during the water-rock interaction. We estimate the original Li content upon deposition and the magnitude of Li depletion both by direct in situ glass measurements and by applying a partition-coefficient approach to plagioclase Li contents. Across our whole sample set (19 eruptive units spanning ca. 10 m.y.), Li losses average 8.9 ppm, with a maximum loss of 37.5 ppm. This allows estimation of the dense rock equivalent of silicic volcanic lithologies required to potentially source a brine deposit. Our data indicate that surficial processes occurring post-eruption may provide sufficient Li to form economic deposits. We found no relationship between deposit age and Li loss, i.e., hydration does not appear to be an ongoing process. Rather, it occurs primarily while the deposit is cooling shortly after eruption, with δ18O and δD in our case study suggesting a temperature window of 40° to 70°C. 

   more » « less
2. Critical Minerals

   https://doi.org/10.1146/annurev-earth-040523-023316  

   Reich, Martin; Simon, Adam C (May 2025, Annual Review of Earth and Planetary Sciences)

   Critical minerals are essential for sustaining the supply chain necessary for the transition to a carbon-free energy source for society. Copper, nickel, cobalt, lithium, and rare earth elements are particularly in demand for batteries and high-performance magnets used in low-carbon technologies. Copper, predominantly sourced from porphyry deposits, is critical for electricity generation, storage, and distribution. Nickel, which comes from laterite and magmatic sulfide deposits, and cobalt, often a by-product of nickel or copper mining, are core components of batteries that power electric vehicles. Lithium, sourced from pegmatite deposits and continental brines, is another key battery component. Rare earth elements, primarily obtained from carbonatite- and regolith-hosted ion-adsorption deposits, have unique magnetic properties that are key for motor efficiency. Future demand for these elements is expected to increase significantly over the next decades, potentially outpacing expected mine production. Therefore, to ensure a successful energy transition, efforts must prioritize addressing substantial challenges in the supply of critical minerals, particularly the delays in exploring and mining new resources to meet growing demands.▪The energy transition relies on green technologies needing a secure, sustainable supply of critical minerals sourced from ore deposits worldwide.▪Copper, nickel, cobalt, lithium, and rare earth elements are geologically restricted in occurrence, posing challenges for extraction and availability.▪Future demand is expected to surge in the next decades, requiring unprecedented production rates to make the green energy transition viable. 

   more » « less
3. 2024 Hydrothermal Geochemistry and Critical Minerals Meeting—Abstracts

   https://doi.org/10.58799/B-166  

   Gysi, A P; Hurtig, N C; Waters, L (June 2024, Bulletin New Mexico Bureau of Mines Mineral Resources)

   Gysi, A P; Hurtig, N C; Waters, L (Ed.)

   A major goal of this conference is to tackle the challenges described above and build a new network of scientists and professionals with different expertise, including but not limited to experimental geochemistry/chemistry, thermodynamic/geochemical modeling and databases, reactive mass transport modeling, molecular dynamic simulations, element extraction/separation technologies, theoretical thermodynamics and equations of state, and mineralogy, ore deposits, and processes in natural systems. Another important aspect is the participation of students and training the next generation of leaders in the field of critical minerals and thermodynamics. Participants at this meeting include scientists from academia and national laboratories, graduate and undergraduate students, as well as liaisons from industry, governmental agencies, and geological surveys. This five-day meeting includes daily talks, keynotes, small workshops, discussion sessions, and two evenings of poster sessions for students. One day includes an excursion to the nearby Lemitar Mountains carbonatite rare earth elements deposit to discover the geology of New Mexico and allow participants to link geosciences with other areas of basic energy sciences. We will also organize a geochemical modeling workshop using our “in-house” MINES thermodynamic database (Gysi et al., 2023) to show an application of thermodynamics to modeling critical mineral deposits. 

   more » « less
4. Thermodynamic modeling of hydrothermal REE partitioning in critical mineral deposits

   Gysi, A.P.; Hurtig, N.; Water, L.; Migdisov, A.; Dub, P.; Zhu, C. (July 2022, Goldschmidt)

   Critical mineral deposits form through an interplay of magmatic-hydrothermal processes in carbonatites and (per)alkaline systems during their emplacement in the Earth’s crust. Hydrothermal aqueous fluids can lead to the mobilization, transport, and deposition of the rare earth elements (REE) coupled to development of alteration zones at the deposit scale [1]. However, unraveling the underlying processes that affect the solubility of REE in these geologic fluids is a challenge in high temperature and pressure fluids [2]. A holistic approach is key to understand the controls of fluid-rock interaction in mobilizing REE in critical mineral deposits. Through a joint effort, we formed a new U.S. geoscience critical minerals experimental–thermodynamic research hub between New Mexico Tech, Los Alamos National Laboratory and Indiana University. The goal of this project is to conduct frontiers research on the behavior of critical elements in supercritical aqueous fluids by integration of a wide array of high temperature solubility experiments complemented by spectroscopic measurements and molecular dynamic simulations. Here we present current advances to simulate a significant vein paragenesis of barite + fluorite +calcite +bastnäsite-(Ce) observed in many critical mineral deposits. A case study will be presented from the Gallinas Mountains REE-fluorite hydrothermal breccia deposit in New Mexico. Using the GEMS code package [3] and the MINES thermodynamic database (https://geoinfo.nmt.edu/mines-tdb), we highlight our current capabilities and limitations to simulate the behavior of REE in these hydrothermal fluids and minerals. A thermodynamic model is presented to simulate the partitioning of REE between calcite- and fluorite-fluid based on recent and ongoing experimental and thermodynamic work on the synthesis of REE doped minerals [4] and REE speciation in acidic and alkaline fluids. We further show how to integrate multiple experimental datasets and develop new thermodynamic models based on the new research efforts from the research hub and future directions to improve our prediction capabilities of REE complexation in supercritical fluids. [1] Gysi et al. (2016), Econ. Geol. 111, 1241-1276; [2] Migdisov et al. (2016), Chemical Geology 439, 13-42. [3] Kulik et al. (2013), Comput Geosci 17, 1–24. [4] Perry and Gysi (2020), Geochim. Cosmochim. Acta 286, 177-197. 

   more » « less
5. The Mina Justa Iron Oxide-Copper-Gold (IOCG) Deposit, Peru: Constraints on Metal and Ore Fluid Sources

   Rodriguez-Mustafa, M.A. (October 2021, Economic geology)

   null (Ed.)

   Iron oxide-copper-gold (IOCG) deposits are major sources of Cu, contain abundant Fe-oxides and may contain Au, Ag, Co, rare earth elements (REE), U and other metals as economically important byproducts in some deposits. They form by hydrothermal processes, but the source of the metals and ore fluid(s) is still debated. We investigated the geochemistry of magnetite from the manto and breccia ore bodies at the Mina Justa IOCG deposit in Peru to assess the source of the iron oxides and their relationship with the economic Cu mineralization. We identified three magnetite types: Type Inclusion (I) is only found in the manto, is the richest in trace elements, and crystallized between 459 - 707 °C; Type Dark (D) has no visible inclusions and formed at around 543 °C; and Type Bright (B) has no inclusions, has the highest Fe content, and formed at around 443 °C. Magnetite samples from Mina Justa yielded an average δ56Fe ± 2σ value of 0.28 ± 0.05‰ (n=9), an average δ18O ± 2σ value 2.19 ± 0.45‰ (n=9), and Δ’17O values that range between -0.075‰ and -0.047‰. Sulfide separates yielded δ65Cu values that range from -0.32‰ to -0.09‰. The trace element compositions and textures of magnetite, along with temperature estimations for magnetite crystallization, are consistent with the manto magnetite belonging to an IOA style mineralization that was overprinted by a younger, structurally-controlled IOCG event that formed the breccia ore body. Altogether, the stable isotopic data fingerprint a magmatic-hydrothermal source for the ore fluids carrying the Fe and Cu at Mina Justa and preclude the input from meteoric water and basinal brines. 

   more » « less