TY - JOUR
T1 - The role of climate in the accumulation of lithium-rich brine in the central andes
AU - Godfrey, L. V.
AU - Chan, L. H.
AU - Alonso, R. N.
AU - Lowenstein, T. K.
AU - McDonough, W. F.
AU - Houston, J.
AU - Li, J.
AU - Bobst, A.
AU - Jordan, T. E.
N1 - Funding Information: We would like to thank Minera del Altiplano (FMC), especially Daniel Chavez Diaz, Gonzalo Tufiño and Rodolfo Mendoza for access to samples and logistical assistance. We would also like to thank Raúl Gutierrez of Borax Argentina SA for his assistance with the collection of water samples. Simone Kasemann, Sue Kay and Scott Hynek provided samples of thermal spring water; and Randall Marrett aided with field studies. The manuscript benefited from all the reviews. This work was supported by NSF Grants ATM-9631291and ATM-9709771 to T.E.J., and ATM-9632359 to T.K.L. Lithium isotope work was supported by National Science Foundation Grants EAR-9506390 and OCE-9905540 to L.H. Chan, EAR 0948549 to W.F.M., and by the ICR policy of the Rutgers School of Environmental and Biological Sciences.
PY - 2013/11
Y1 - 2013/11
N2 - Lithium-rich brine within the sub-surface of the Salar del Hombre Muerto (SHM) salt pan in the Andes of northwestern Argentina has a chemical and isotopic composition which is consistent with Li derived from several sources: the modern halite saturated lagoon, Li-rich salts and brines formed recently, and dissolution of halite which precipitated from ancient saline lakes. SHM lies in the closed basin that includes part of the massive Cerro Galán caldera which is drained by the Río los Patos, which is responsible for 90% of surface runoff into the salar. The low Li isotope composition, +3.4‰, of this river is consistent with significant contributions of geothermal spring water. As water drains through the volcaniclastic deposits which cover a large proportion of the basin, Li removal, as indicated by decreasing Li/Na, occurs but without significant isotope fractionation. This indicates a mechanism of surface sorption onto smectite or ferrihydrite rather than Li incorporation into octahedral structural sites of clays. These observations suggest that conditions in this high altitude desert have limited the dilution of hydrothermal spring water as well as the formation of clay minerals, which jointly have allowed the Li resource to accumulate rapidly. Changes in climate on a multi-millennial time scale, specifically in the hydrologic budget, have resulted in solute accumulation rates that have been variable through time, and decoupled Li and Na fluxes. Inflow to the salar under modern conditions has high Li/Na (7.9×10-3 by wt) with δ7Li indistinguishable from basement rocks (-0.3‰ to +6.4‰), while under pluvial climate conditions the Li/Na of the saline lake was 40 times lower than the modern lagoon (0.1-0.3×10-3 compared to 10.6-13.4×10-3) with slightly higher δ7Li, +6.9‰ to +12.3‰, reflecting the uptake of 6Li into secondary minerals which formed under a wetter climate.
AB - Lithium-rich brine within the sub-surface of the Salar del Hombre Muerto (SHM) salt pan in the Andes of northwestern Argentina has a chemical and isotopic composition which is consistent with Li derived from several sources: the modern halite saturated lagoon, Li-rich salts and brines formed recently, and dissolution of halite which precipitated from ancient saline lakes. SHM lies in the closed basin that includes part of the massive Cerro Galán caldera which is drained by the Río los Patos, which is responsible for 90% of surface runoff into the salar. The low Li isotope composition, +3.4‰, of this river is consistent with significant contributions of geothermal spring water. As water drains through the volcaniclastic deposits which cover a large proportion of the basin, Li removal, as indicated by decreasing Li/Na, occurs but without significant isotope fractionation. This indicates a mechanism of surface sorption onto smectite or ferrihydrite rather than Li incorporation into octahedral structural sites of clays. These observations suggest that conditions in this high altitude desert have limited the dilution of hydrothermal spring water as well as the formation of clay minerals, which jointly have allowed the Li resource to accumulate rapidly. Changes in climate on a multi-millennial time scale, specifically in the hydrologic budget, have resulted in solute accumulation rates that have been variable through time, and decoupled Li and Na fluxes. Inflow to the salar under modern conditions has high Li/Na (7.9×10-3 by wt) with δ7Li indistinguishable from basement rocks (-0.3‰ to +6.4‰), while under pluvial climate conditions the Li/Na of the saline lake was 40 times lower than the modern lagoon (0.1-0.3×10-3 compared to 10.6-13.4×10-3) with slightly higher δ7Li, +6.9‰ to +12.3‰, reflecting the uptake of 6Li into secondary minerals which formed under a wetter climate.
UR - https://www.scopus.com/pages/publications/84884361871
UR - https://www.scopus.com/pages/publications/84884361871#tab=citedBy
U2 - 10.1016/j.apgeochem.2013.09.002
DO - 10.1016/j.apgeochem.2013.09.002
M3 - Article
SN - 0883-2927
VL - 38
SP - 92
EP - 102
JO - Applied Geochemistry
JF - Applied Geochemistry
ER -