Geochemical Analysis of Evaporitic Deposits

Evaporitic deposits, comprising minerals such as halite, gypsum and anhydrite, form by the progressive concentration and crystallisation of saline waters. Geochemical analysis of these sediments employs major‐ and trace‐element assays, stable isotope measurements (notably of oxygen, sulfur and strontium), fluid inclusion microthermometry and petrographic characterisation. Together, these techniques reveal the composition and evolution of parent brines, depositional conditions (salinity, temperature, redox state) and diagenetic pathways. Such studies underpin reconstructions of past climate changes, basin hydrology and tectonic settings, and they inform exploration for potash, lithium and hydrocarbon resources. Recent advances include high‐precision isotope ratio mass spectrometry, in situ microprobe analysis of individual fluid inclusions and coupled geochemical–geophysical modelling, enabling more detailed palaeoenvironmental and reservoir quality assessments worldwide.

Research from Nature Portfolio

A foundational contribution utilised fluid inclusion homogenisation temperatures in continental halite to reconstruct Late Eocene–early Oligocene brine palaeotemperatures. Homogenisation data from primary chevron and cumulate halite textures yielded temperature ranges far exceeding modern analogues, indicating episodic high‐temperature conditions in shallow saline basins. These results have refined models of Cenozoic climate extremes and provided a robust proxy for palaeotemperature reconstructions in evaporitic systems.

Geochemical Analysis of Evaporitic Deposits publication trend

The graph below shows the total number of articles in geochemical analysis of evaporitic deposits across all publications each year (not limited to Nature Index journals).

Technical terms

Evaporitic deposit: A sedimentary accumulation of salts precipitated from evaporating saline waters.

Brine: A highly concentrated aqueous solution of dissolved salts from which evaporite minerals crystallise.

Fluid inclusion: A microscopic pocket of trapped fluid within a mineral, preserving original brine composition and conditions.

Homogenisation temperature: The temperature at which a fluid inclusion becomes a single phase during heating, used as a proxy for trapping temperature.

Stable isotope ratio: The proportion of heavy to light isotopes of an element (e.g. 87Sr/86Sr, δ34S, δ18O), indicating source and evolution of fluids.

Diagenesis: The suite of physical, chemical and biological processes that alter sediments after deposition, affecting mineralogy and porosity.

References

1. Late Eocene to early Oligocene quantitative paleotemperature record: Evidence from continental halite fluid inclusions. Scientific Reports (2014).
2. Geochemistry and Sr, S, and O stable isotopes of Miocene Abu Dhabi evaporites, United Arab Emirates. Heliyon (2023).
3. Sr, S, and O Isotope Compositions of Evaporites in the Lanping–Simao Basin, China. Minerals (2021).
4. S and Sr Isotope Compositions and Trace Element Compositions of the Middle Jurassic Evaporites in Eastern Tibet: Provenance and Palaeogeographic Implications. Minerals (2022).