Stable isotopes of gypsum hydration water in recent playa-lake sedimentsimplications for paleoclimate reconstructions

  1. Jorge Cañada-Pasadas 1
  2. Fernando Gázquez 1
  3. Lucía Martegani 1
  4. Claudia Voigt 1
  5. Antonio García Alix 2
  6. Gonzalo Jiménez Moreno 2
  7. Miguel Rodríguez Rodríguez 3
  1. 1 Department of Biology and Geology, University of Almería, Carretera de Sacramento sn. La Cañada de San Urbano, 04120 Almería, Spain.
  2. 2 Department of Stratigraphy and Paleontology. Campus de Fuentenueva. University of Granada. Granada, Spain
  3. 3 Department of Physical, Chemical and Natural Systems, Pablo de Olavide University, Seville, Spain.
Show affiliations +
Journal:
Geogaceta

ISSN: 0213-683X

Year of publication: 2024

Issue: 76

Pages: 71-74

Type: Article

DOI: 10.55407/GEOGACETA104479 DIALNET GOOGLE SCHOLAR lock_openOpen access editor

More publications in: Geogaceta

Abstract

We investigate the oxygen and hydrogen stable isotopes of hydration water in gypsum (CaSO 4·2H2O) from surface sediment of Laguna de la Ratosa playa-lake (northern Málaga Province, Spain). We aim to enhance the understanding of how lacustrine gypsum from playa-lakes can be used for paleoclimate reconstruction. Gypsum samples were collected at 30-meter intervals along a transect from the shore to the depocenter of the lake. Comparison of δ18 O and δ2 H values of gypsum hydration water with the modern seasonal isotope variability of lake water points to gypsum formation in spring and early summer, before complete desiccation of the lake. An increasing trend in the δ18O and δ2H values of gypsum hydration water, by ~1,5 and ~15‰, respectively, is observed from the shore to the depocenter. This indicates that coeval gypsum formed in different parts of the lakebed record slightly different isotopic values of the lake water during precipitation. This spatial variability should be considered when interpreting stable isotope series of gypsum hydration water from ephemeral lake sediments.

Data source: Dialnet