1,721,052 research outputs found
Oxygen isotope equilibrium in sulfate–water systems: A revision of geothermometric applications in low-enthalpy systems
No full textComments on “Lithium-rich geothermal brines in Europe: An up-date about geochemical characteristics and implications for potential Li resources” by Sanjuan et al. (2022)
No full textGeochemical and isotope-geochemical study of compositionally extreme and thermal waters from Northern Apennines (Italy)
No full textAn update on lithium mica thermodynamics and its geothermometrical application
No full textThe extraction of lithium from geothermal brines is one of the most promising fields for mining this important element, which plays and will play an increasingly important role in the transition to green energy. Despite this, a thermodynamic database of lithium minerals –which would be useful in geochemical modeling of Li cycling- is still far from complete. In this short communication, the thermodynamic (in particular molar heat equation) and solubility data of a lithium mica mineral with a generic formula KLi0.5Al1.5Si4O10(OH)2 are revised. Furthermore, the solubility data as log(K) are inserted in commonly available thermodynamic databases and applied to the geothermometrical study of the lithium-rich geothermal waters of the Upper Rhine Graben. The general agreement between the temperatures obtained from the equilibrium reaction involving lithium mica and the values already published or from a multicomponent geothermometrical approach confirms the usefulness and importance of lithium mica in the study of lithium-rich geothermal brines
Application of brine differentiation and Langelier–Ludwig plots to fresh-to-brine waters from sedimentary basins: Diagnostic potentials and limits
No full text
Springs and streams of the Taro–Ceno Valley(Northern Apennine, Italy): Reaction path modeling of waters interacting with serpentinized ultramafic rocks
No full textIn the area of the Taro–Ceno Valleys (Northern Apennine, Emilia-Romagna region, Italy), waters of meteoric origin interact with ophiolite rocks of the External Ligurides. Fresh water springs issuing from basalts have a Ca–HCO3 composition, whereas freshwater springs from ultramafites vary in composition from Ca–HCO3 or Mg–HCO3 to Na–OH or Na–SO4 types and in pH values from 7.3–8.8 up to pH 11, respectively. In addition, the
boron content of the alkaline waters is up to 13 mg/L, which is unusually high for freshwaters in general and ultramafites that have undergone oceanic serpentinisation in particular and gives a boric alkalinity to the waters. The springs waters show evidence of recent low-temperature continental serpentinisation and the
process is modeled by reaction paths using an updated geochemical thermodynamic database, consistent
with the local primary and secondary serpentinite paragenesis. For the model, bicarbonate waters evolve to alkaline waters supersaturated in Ca–(Mg)-carbonate, based on the assumption that the dissolution of serpentinite results in supersaturation with respect to kaolinite, ferrihydrite, vermiculite, Fe2+–Mg2+-
saponite, and poorly crystalline serpentine. The alkaline composition and the chloride content of the waters suggest a prolonged interaction with the rocks at depth that led to dissolution of albite and leaching of olivine-hosted fluid inclusions. A similar evolution is also proposed for the more developed springs issuing from the ultramafic rocks of the Voltri Group (Liguria region), where solutions are supersaturated in brucite and are in equilibrium with enstatite and/or chlorite
Constraining lithium-clay equilibria in sedimentary environments using a new thermodynamic dataset
No full textLithium-rich formation brines from sedimentary basins are emerging as key unconventional resources in response to the growing global demand for lithium. This study integrates geochemical data from diverse settings, including the Smackover and Edwards Formations (Gulf Coast, USA), the Alberta Basin (Canada), and Salsomaggiore (Northern Apennine, Italy), to investigate the role of diagenetic processes and clay mineral equilibria on lithium mobility and retention. A new thermodynamic dataset was developed for lithium-bearing clay minerals and jadarite, allowing the construction of activity diagrams, calculation of saturation indices, and modeling. Activity diagrams indicate progressive brine evolution from kaolinite to montmorillonite, and toward Mg-rich saponite/chlorite assemblages, consistent with advanced diagenetic stages and lithium uptake into octahedral sites. The transition from equilibrium with smectites to chlorite-like phases reflects increasing temperature and prolonged water-rock interactions. A hyperalkaline paleo-fluid in equilibrium with jadarite and associated phases was also modeled, indicating that lithium concentrations in the Jadar Basin may have reached levels comparable to those currently observed in the Salar de Atacama. These findings underscore the dual role of clay minerals as buffers and potential sources for lithium in sedimentary systems, providing new insights for exploration and geochemical modeling of lithium-rich formation brines
- …
