The hydrogeochemistry of shallow groundwater from Lut Desert, Iran: The hottest place on Earth

W. Berry Lyons (1) , Susan A Welch (1) , Christopher B Gardner (1) , Arash Sharifi (2) , Amir Aghakouchak (3) , Marjan Mashkour (4, 5) , Morteza Djamali (6) , Zeinab Matinzadeh (2) , Sara Palacio (7) , Hossein Akhani (2)

1 ARM
2 Halophytes and C4 Plants Research Laboratory, Department of Plant Sciences, School of Biology, College of Science, University of Tehran
3 Department of Civil and Environmental Engineering [Irvine]
4 AASPE - Archéozoologie, archéobotanique : sociétés, pratiques et environnements
5 University of Tehran, Faculty of Environment, Enghelab avenue Ghosd street, Tehran, Iran
6 IMBE - Institut méditerranéen de biodiversité et d'écologie marine et continentale
7 IPE - Instituto Pirenaico de Ecologia = Pyrenean Institute of Ecology

This paper presents the first shallow groundwater geochemical data from the Lut Desert (Dasht-e-Lut), one of the hottest places on the planet. The waters are Na-Cl brines that have undergone extensive evaporation, but they are unlike seawater derived brines in that the K + is low and the Ca 2+ > Mg 2+ and HCO 3 − > SO 4 2−. In addition to evapo-concentration, the most saline samples indicate that the dissolution of previously deposited salt also acts as a major control on the geochemistry of these waters. High concentrations of gypsum in surface soils along with the water geochemistry indicate the dissolution, precipitation, and reprecipitation of evaporite salts are very important to the overall chemistry of the near surface environment. As demonstrated by the high H 4 SiO 4 concentrations, the weathering of aluminosilicate minerals also contributes to the solutes present. Fixed nitrogen (NO 3 − + NO 2 −) concentrations suggest little to no denitrification is occurring in these waters. The processes controlling the geochemistry of the Lut waters are similar to those in other hyperarid regions of the Earth.

Domains: Environmental Sciences

W. Berry Lyons, Susan A Welch, Christopher B Gardner, Arash Sharifi, Amir Aghakouchak, et al.. The hydrogeochemistry of shallow groundwater from Lut Desert, Iran: The hottest place on Earth. Journal of Arid Environments, 2020, 178, pp.104143. ⟨10.1016/j.jaridenv.2020.104143⟩. ⟨hal-02508657⟩