A database of the elemental and isotopic composition of water and carbonates from a hypersaline Andean lake (Laguna del Peinado, Argentina)

The dataset presented here encompasses the results of the geochemical analyses of water and recent carbonate samples collected in the El Peinado basin located in the Southern Puna Plateau in Catamarca, Argentina. This system formed by the hypersaline lake Laguna del Peinado, numerous hydrothermal springs, and the small hypersaline lake Laguna Turquesa, provides a natural laboratory to study carbonate formation and the mechanisms that control the incorporation of various elements and isotopes into their structure under a broad range of geochemical conditions. Geochemical analyses include data on the physicochemical parameters, elemental, and isotopic (δ18O, δ2H, δ11B) composition of the waters, and data on the elemental and isotopic (δ18O, δ13C, δ11B) composition of the carbonates. These data allowed us to calculate element partition coefficients and isotopic fractionation between coupled water-carbonate samples from this natural setting, which are also included here. This dataset also includes the results of water modelling using the software PHREEQC, which contains data on the chemical speciation of carbon and boron, the species contributing to total alkalinity, and mineral saturation indices. This information is useful for all those dealing with geochemistry of hypersaline lakes, geochemistry of continental carbonates, as well as paleoenvironmental and paleoclimatic studies using lake carbonates as archives. These data correspond to the research article “On the origin and processes controlling the elemental and isotopic composition of carbonates in hypersaline Andean lakes”. The full description of the data is provided in the data description file.

Sampling method During fieldwork in January 2019, November 2019 and February 2021 (austral spring-summer), water samples were collected for isotopic and elemental analyses from the main water body Laguna del Peinado, the smaller Laguna Turquesa, the inflowing hydrothermal springs, and the wetlands. Rainwater was sampled in the nearest town, Antofagasta de la Sierra (3320 m a.s.l.) approximately 80 km to the NE and snow was collected at nearly 5000 m a.s.l., 17 km SE of the lake. For elemental analyses, water samples were filtered and an aliquot was acidified for metals determinations. Short sediment cores (< 1 m) were recovered from Laguna del Peinado using a raft equipped with an Uwitec coring device. Carbonate and surface sediment samples were collected from the lakes, hot springs, and catchment area, packed in polyethylene vials and plastic bags, and stored at 4°C.