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Cited by 20Groundwater and Isotope GeochemistryGeochemistry and Elemental AnalysisGeological and Geochemical Analysis

Chemical and isotopic features of Li-rich brines from the Salar de Olaroz, Central Andes of NW Argentina

Open access
Franco, M. Gabriela, Peralta Arnold, Yesica J., Santamans, Carla D., López Steinmetz, Romina L., Tassi, Franco, Venturi, Stefania, Jofré, Cynthia B., Caffe, Pablo J. +1 more·2020·Journal of South American Earth Sciences
DOI 10.1016/j.jsames.2020.102742
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Abstract

Abstract The lithium-rich brines of the Salar de Olaroz in the Central Andes of NW Argentina are considered to be of great economic and strategic interest. This study focused on the fluid source(s) and geochemical processes governing the chemical and isotopic characteristics of the surficial waters of Olaroz (residual brines, ephemeral lakes, rivers and tributary streams), aiming to define the mechanisms leading to such a huge Li reservoir. The chemistry of the Rosario River, which is one of the main sources of recharge of the Salar de Olaroz, is mostly controlled by fluid inputs from hydrothermal systems located north of the salar (in the volcanic areas of Rosario de Coyaguayma, Pairique, and Cono Panizo). The hydrothermal fluids are characterized by relatively high Li concentrations, as they interact with Li-rich rocks pertaining to Miocene – Pliocene volcanic formations, Ordovician sedimentary deposits, and, possibly, pre-Ordovician crystalline basement. In the salar, the hyperarid climate regulates the relative proportion between supplied waters and evaporation, inducing deposition/dissolution of salts, which controls the concentrations of main ions in brines and ephemeral lakes. Hence, the peculiar combination of a Li-rich primary source, the hydrothermal scavenging by geothermal fluids that feed the Rosario River, and secondary concentration processes affecting the surficial water within the salar leads to the formation of the huge Li reservoir characterizing this area.

AI snapshot

Written from the paper’s full text.

TL;DR

This study investigates the fluid sources and geochemical/isotopic processes controlling Li-rich surficial waters and brines of the Salar de Olaroz, NW Argentina. It concludes that hydrothermal fluids from northern volcanic areas feed the Rosario River, and that evaporation plus salt deposition/dissolution in the hyperarid salar produce the huge Li reservoir.

Key findings

  • The Rosario River is the main recharge source to the salar, with a mean annual base flow of ~8.5 × 10⁶ m³; its Li concentration is 16 mg/L, more than fivefold higher than the Archibarca River (3 mg/L), while thermal springs connected to it reach up to 29 mg/L Li.
  • Brines are Na⁺–Cl⁻ type, with TDS from 37,400 to 332,000 mg/L and Li concentrations from 115 to 1570 mg/L, with the maximum in the north-central salar (sample R6).
  • All waters show positive δ¹⁸O and δD shifts relative to the Local Meteoric Water Line and fit an evaporation line of δD = 4.86 × δ¹⁸O − 35.5 (r² = 0.97); the inferred recharge altitude is 5000–5500 m a.s.l.
  • Saline-nucleus brines are over-saturated with respect to carbonates, sulfate-bearing salts, and chloride salts, whereas peripheral brines are over-saturated in carbonates but undersaturated in SO₄-bearing and Cl-bearing minerals.

Methods

  • Three water groups were sampled from Salar de Olaroz and surroundings: inflow waters (rivers and creeks), ephemeral lakes, and brines; sampling occurred during February 2015, September 2015, April 2016, and October 2016. Brines were collected at 5–150 cm depths from pits, plus one shallow well (0.69 m) and one spring.
  • Temperature, pH, and electrical conductivity were measured in the field; alkalinity was analyzed by acidimetric titration; major anions and cations by ion chromatography and ICP-AES; stable isotopes (δ¹⁸O-H₂O and δD-H₂O) by cavity ring-down spectrometry.
  • Saturation indices for gypsum, dolomite, aragonite, calcite, anhydrite, glauberite, halite, mirabilite, sylvite, and thenardite were computed with PHREEQC 3.4.0 using the Pitzer database.

Limitations

  • The paper states no explicit limitations.
  • Evident from the text: Li concentrations for ephemeral lakes E1–E3 were not available in this study, and several isotopic values are reported as “nd” in Table 1.
  • Evident from the text: the study focuses on surficial waters and brines; the hydraulic connection between Olaroz and Cauchari cannot be ruled out, and deep reservoir sampling is not presented.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/j.jsames.2020.102742

Cites

46 of 46 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 18 cited sources checked · 0 supported · 0 flagged

  • Findingnone given

    The highest TDS values are found in brines located near the north-central part of the salar nucleus.

    “The highest TDS values are indeed found in brines located near the north-central part of the salar nucleus.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Brines located within the saline nucleus (R1, R2, R3, R4, R5, R6, R8, R9, and R12) are over-saturated in all these mineral species.

    “In contrast, brines located within the saline nucleus (R1, R2, R3, R4, R5, R6, R8, R9, and R12) are over-saturated in all these mineral species (Table 2).”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: Precipitation is assumed to occur for minerals showing positive saturation index values (over-saturation conditions).
  • Findingown data

    All inflow waters have moderate concentrations of Li+ (up to 19 mg/L).

    “All these waters have moderate concentrations of Liþ(up to 19 mg/L).”
    Quote in the paperNot a substantial claim
  • Findingown data

    The δ18O-H2O and δD-H2O values of inflow waters range from -8.08‰ to -4.8‰ and from -74.7‰ to -67.09‰ vs. VSMOW, respectively.

    “The δ 18 O-H 2 O and δD-H 2 O values of inflow waters range from À 8.08‰ to À 4.8‰ and from À 74.7‰ to À 67.09‰ vs. VSMOW, respectively.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Samples collected from the ephemeral lakes are undersaturated with respect to all the salts (except sample E4 which is over-saturated with respect to aragonite, calcite, and dolomite).

    “Samples collected from the ephemeral lakes are undersaturated with respect to all the salts (except sample E4 which is over-saturated with respect to aragonite, calcite, and dolomite).”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: Precipitation is assumed to occur for minerals showing positive saturation index values (over-saturation conditions).
  • May combine two claims. 19
  • Classified as probably not a substantial claim. 4

  • May combine two claims.

    Findingown data

    Ephemeral lakes have δ18O-H2O values ranging from -9‰ to 13.1‰ vs. VSMOW and δD-H2O values from -80.6‰ to 33.4‰ vs. VSMOW.

    “Ephemeral lakes have δ 18 O-H 2 O values ranging from À 9‰ to 13.1‰ vs. VSMOW and δD-H 2 O values from À 80.6‰ to 33.4‰ vs. VSMOW.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The δ18O-H2O and δD-H2O values of meteoric water (MW) are -6.2‰ and -50.8 vs. VSMOW, respectively.

    “The δ 18 O-H 2 O and δD-H 2 O values of meteoric water (MW) are À 6.2‰ and À 50.8 vs. VSMOW, respectively (Table 1).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    The Rc/Ra values (up to 1.26 in the thermal springs of Rosario de Coyaguayma) reveal the occurrence of significant amounts of mantle-derived He (up to 16%) whose uprising to the surface through a thick crust implies the occurrence of deep tectonic structures.

    “This hypothesis was supported by the Rc/Ra values (up to 1,26 in the thermal springs of Rosario de Coyaguayma), revealing the occurrence of significant amounts of mantle-derived He (up to 16%) whose uprising to the surface through a thick crust implies the occurrence of deep tectonic structures.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Brines have δ18O-H2O values from -6.7‰ to 13‰ vs. VSMOW and δD-H2O values from -66.7‰ to 21.7‰ vs. VSMOW.

    “Brines have δ 18 O-H 2 O values from À 6.7‰ to 13‰ vs. VSMOW and δD-H 2 O values from À 66.7‰ to 21.7‰ vs. VSMOW.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Inflow waters are of the Na+/Cl- type, except samples I2 and I3 that show Na+-SO4 2-(Cl-) and Na+-HCO3-(Cl-) compositions.

    “They are of the Na þ / Cl À type, except for samples I2 and I3 that show Na þ -SO 4 2-(Cl À ) and Na þ -HCO 3 -(Cl À ) compositions, respectively (Fig. 2a and b).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Brines are of the Na+-Cl- type and show the highest concentrations of Li+ (up to 1500 mg/L).

    “These waters are of the Na þ -Cl -type (Fig. 2a and b) and show the highest concentrations of Li þ (up to 1500 mg/L).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Most brine samples are over-saturated in aragonite, calcite, dolomite, anhydrite (except samples R7, R10, R13, and R14), gypsum (except samples R7, R10, R13, and R14), glauberite, and halite (except samples R7, R10, R11, R13, and R14).

    “Most brine samples are over-saturated in aragonite, calcite, dolomite, anhydrite (except samples R7, R10, R13, and R14), gypsum (except samples R7, R10, R13, and R14), glauberite, and halite (except samples R7, R10, R11, R13, and R14).”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: Precipitation is assumed to occur for minerals showing positive saturation index values (over-saturation conditions).

  • May combine two claims.

    Findingnone given

    The Rosario River has a relatively high concentration of Li (16 mg/L), more than fivefold higher than that measured in the Archibarca River (3 mg/L).

    “As far as the Li origin and fate are concerned, it is worth noting that the Rosario River has a relatively high concentration of Li (16 mg/L), i.e. more than fivefold higher than that measured in the Archibarca River (3 mg/L).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The effects of evaporation and salt dissolution on δ18O-H2O values and TDS are clearly shown in Fig. 5: the former process is dominant for most ephemeral lakes, except for E4.

    “The effects of evaporation and salt dissolution on δ 18 O-H 2 O values and TDS are clearly shown in Fig. 5: the former process is dominant for most ephemeral lakes, except for E4 (which during our surveys was not present at the surface).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The chemistry of the thermal springs, creeks, and ephemeral lakes is affected by dissolution/deposition processes mostly occurring at shallow depth within the salar where the arid climate caused strong evaporation, eventually producing extreme Na+ and Cl- enrichments.

    “Furthermore, it is affected by the dissolution/deposition processes mostly occurring at shallow depth within the salar where the arid climate caused strong evaporation, eventually producing extreme Na þ and Cl À enrichments (Fig. 4a).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    In the salar, the hyperarid climate regulates the relative proportion between supplied waters and evaporation, inducing deposition/dissolution of salts, which controls the concentrations of main ions in brines and ephemeral lakes.

    “In the salar, the hyperarid climate regulates the relative proportion between supplied waters and evaporation, inducing deposition/dissolution of salts, which controls the concentrations of main ions in brines and ephemeral lakes.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Brines concentrate as evaporation (i.e., water loss) induces salt precipitation.

    “Brines concentrate as evaporation (i.e., water loss) induces salt precipitation (Eugster, 1980;Munk et al., 2018).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Eugster, 1980 source

      Not checked in the free run.

    • cites Munk et al., 2018 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The Rosario headwaters include several hydrothermal springs in different parts of the catchment areas.

    “The Rosario headwaters include several hydrothermal springs in different parts of the catchment areas (Peralta Arnold et al., 2017, Fig. 1).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Peralta Arnold et al., 2017 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Some hydrothermal springs significantly supply the Rosario River, and are related to the same hydrological system involving volcanic rocks, tuffs, fluvio-lacustrine sediments and evaporitic deposits, as supported by the relatively high TDS of the Na+-Cl--type I1 sample.

    “Some of these hydrothermal springs significantly supply the Rosario River, and are related to the same hydrological system involving volcanic rocks, tuffs, fluvio-lacustrine sediments and evaporitic deposits, as supported by the relatively high TDS of the Na þ -Cl --type I1 sample (Table 1 and Fig. 1).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    Although the composition of brines is controlled by the two processes (i.e., evaporation and salt dissolution), evaporation largely dominates over dissolution especially in samples collected at relatively shallow depths (R1, R3, R4, R5, and R6).

    “Although the composition of brines is controlled by the two processes (i.e., evaporation and salt dissolution), evaporation largely dominates over dissolution especially in samples collected at relatively shallow depths (R1, R3, R4, R5, and R6).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The recharge altitude (5000-5500 m) is significantly higher than that suggested by local rain water and is consistent with the hypothesis that the northern sector of the basin, with altitudes up to 5800 m a.s.l., feeds the Rosario River.

    “This recharge altitude, significantly higher than that suggested by the values of the local rain water (MW; Fig. 3), is consistent with the hypothesis that the northern sector of the basin, with altitudes up to 5800 m a.s.l.(e.g.Nevado de San Pedro; Fig. 1), feeds the Rosario River.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The production of Li-salts involves two sources of water: brines and brackish water, the latter possibly provided by the Archibarca River.

    “The production of Li-salts involves two sources of water (Orocobre, 2018): brines and brackish water, the latter being possibly provided by the Archibarca River.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Orocobre, 2018

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationnone given

    Water usage for lithium carbonate production may significantly modify the water balance of the basin, leading to dramatic consequences for this delicate natural system.

    “It is worth noting that the water usage for lithium carbonate production may significantly modify the water balance of the basin, leading to dramatic consequences for this delicate natural system.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Li can reach extremely high concentrations in the Olaroz brines because Li is not limited by the mineral deposition that affects other ions.

    “On the contrary, Li can reach extremely high concentrations as this metal is not limited by the mineral deposition that affects other ions.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Highly soluble minerals able to incorporate Li can form only when water evaporation is almost complete.

  • May combine two claims.

    Interpretationreasoning

    The Li-rich brines of the Salar de Olaroz are ruled by climate, contribution of hydrothermal fluids, and secondary dissolution/evaporation processes.

    “In summary, the Li-rich brines of the Salar de Olaroz are ruled by (i) climate, (ii) contribution of hydrothermal fluids, and (iii) secondary dissolution/evaporation processes.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The chemistry of the Olaroz brines is mainly ruled by the geochemical features of the Rosario River, whose evolution, as a consequence of strong evaporation, follows the sulfation pathway.

    “The chemistry of the Olaroz brines is mainly ruled by the geochemical features of the Rosario River, whose evolution, as a consequence of the strong evaporation, follows the sulfation pathway.”
    Quote in the paperSubstantial claim
21 of 21

  • The authors state this as an assumption.

    Precipitation is assumed to occur for minerals showing positive saturation index values (over-saturation conditions).

    “Precipitation is supposed to occur for those minerals showing positive SI values (over-saturation conditions).”

  • The paper relies on this without support.

    Highly soluble minerals able to incorporate Li can form only when water evaporation is almost complete.

    “since the highly soluble minerals able to incorporate this element can form only when water evaporation is almost complete.”
2 of 2

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • The model proposed for the formation of Atacama's and Olaroz's brines took place in a near-surface setting through geochemical processes such as low-temperature weathering, evaporation, formation of transition-zone brines, and crystallization of halite to increase Li concentration.

    “This would be consistent with the model proposed for the formation of the Atacama's and Olaroz's brines, which took place in a near-surface setting through geochemical processes such as low-temperature weathering, evaporation, formation of transition-zone brines, and ultimately crystallization of halite to increase the concentration of Li in the brines (Munk et al., 2018;Franco et al., 2020).”

    From Brine grades in Andean salars: When basin size matters A review of the Lithium Triangle (2021) · cites this paper as Franco et al., 2020

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Discussion names brine samples R17 and R21 that were not collected

    Minor

    The discussion identifies R17 and R21 as brines, but the sampling description's brine IDs end at R14.

  • Inflow-water TDS range excludes sample I4

    Minor

    The stated maximum TDS for inflow waters is 6623 mg/L, but Table 1 reports 7610 mg/L for inflow creek I4.

  • Saline-nucleus brines are not oversaturated in all listed minerals

    Minor

    The discussion says nucleus brines are oversaturated in all the carbonate, sulfate-bearing, and chloride-bearing minerals just listed. For example, Table 2 gives negative saturation indices for mirabilite, sylvite, and thenardite in nucleus brine R1.

  • Inflow-water pH minimum does not match Table 1

    Minor

    The results give a minimum inflow-water pH of 7.34, whereas the lowest pH among the five inflow samples in Table 1 is 7.41, for I2.

4 of 4

Cites

Flagged first, then by citations

Research works printed but not linked: 6

  1. Hardie, 1970, vol. 3, 273
  2. Moraga, 1974, Estudio geológico del Salar deAtacama, vol. 29, 56
  3. Schwab, 1973, vol. 43, 168
  4. Smoot, 1991, Depositional environments of non-marine evaporites, vol. 50, 189
  5. Turner, 1959, Estratigrafía del Cordón de Escaya y la Sierra de Rinconada, Jujuy, Rev. Asoc. Geol. Argent., 15, 15
  6. Turner, 1964, 103, 109

Cited by

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Related

Authors
Franco, M. G., Peralta Arnold, Y. J., Santamans, C. D., López Steinmetz, R. L., Tassi, F., Venturi, S., Jofré, C. B., Caffe, P. J., & Córdoba, F. E.
Affiliations
  • Consejo Nacional de Investigaciones Científicas y Técnicas (AR)
  • Institute of Geosciences and Earth Resources (IT)
Corresponding author
Franco, M. Gabriela
ORCID
Venue
Journal of South American Earth Sciences
Publisher
Elsevier BV
Published
2020-11
Volume
103
Pages
102742
ISSN
0895-9811 (ISSN-L)
DOI
10.1016/j.jsames.2020.102742
OpenAlex
W3043570123
Semantic Scholar
cc0ab44ffad202cd6c947ed653f415801ca1cb94
Cited by
20
References
46
Citations by year
2026: 3 · 2025: 6 · 2024: 3 · 2023: 3 · 2022: 4 · 2021: 1
FWCI
1.27
Type
journal article
Language
en
Open access
Licence
Locations
  • Journal of South American Earth Sciences (publishedVersion)
  • Florence Research (University of Florence) (submittedVersion, other-oa)
  • CONICET Digital (CONICET) (submittedVersion, cc-by-nc-sa)
Funders
  • Agencia Nacional de Promoción Científica y Tecnológica (PICT-V-2014-3654)
  • Fondo para la Investigación Científica y Tecnológica
  • Consejo Nacional de Investigaciones Científicas y Técnicas (PIO-2015/201614020140100010CO)
Topics
  • Physical Sciences › Earth and Planetary Sciences › Geochemistry and Petrology › Groundwater and Isotope Geochemistry
  • Physical Sciences › Earth and Planetary Sciences › Geochemistry and Petrology › Geochemistry and Elemental Analysis
  • Physical Sciences › Earth and Planetary Sciences › Geophysics › Geological and Geochemical Analysis
Keywords
lithium-rich brines, hydrothermal fluids, evaporite deposition, evaporite dissolution, isotope geochemistry, brine chemistry, ephemeral lakes, hyper-arid climate, geothermal fluids

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