283 Critical Mineral Resources and Recovery in the Americas: Emerging Methods in Exploration and Sustainable Extraction, Part II

This session explores the role of critical minerals in technology and the low-carbon economy, focusing on geological discoveries, sustainable extraction methods, and recycling to support secure, environmentally responsible mineral supply chains in the Americas.

Wednesday, 22 October 2025
1:30 PM - 5:30 PM
HBGCC, 217A

Lithium Variability within a Single Exploration Well - Duperow Formation, Saskatchewan

Paper number: 283-10
Program: Technical Sessions
Time: 3:55 PM – 4:10 PM

Authors

Abstract

Basinal brine-hosted lithium (Li) deposits are emerging as an important source of this critical mineral, with significant resources being discovered in sedimentary basins across North America. They are projected to have lower production costs and environmental impacts (i.e. land footprint and water usage) compared to salar, pegmatite, and volcano-sedimentary clay deposits. Despite their increasing prominence, the processes that generate Li-rich brines are not well constrained and studies investigating the Li source are typically regional in scale and seldom consider local variations. The Late Devonian Duperow Formation within the Williston Basin of southeastern Saskatchewan is a highly prospective target for Li and hosts some of the highest-grade brines in North America outside of the Smackover Formation.

Here, geochemical and isotopic variations in brines collected from five intervals of the Duperow Formation during production testing of an exploration well were investigated. Lithium concentrations covered a broad range from 85 to 241 mg/L, consistent with previous observations, and were not correlated with either depth or temperature. Halogen systematics indicated a common brine evolution trajectory for all samples, characterized by seawater evaporation. Geochemical modelling showed samples with the highest Li concentrations were generally less saturated in chloride minerals and more saturated in sulphate mineral phases relative to the other samples. Lithium isotopic ratios occupied a narrow range of 13.2 to 14.7 permille despite a wide range in Li concentrations, suggesting a common Li source. We interpret that Li enrichments in basinal brines are generated through a complex interplay between Li-bearing sediments, fluid geochemistry, diagenetic reactions, and mineral solubility. Accordingly, identifying Li brine potential requires a comprehensive understanding of a given basin, including both geological and geochemical characteristics. Additionally, variations in Li concentration within a formation are important to consider when developing a mineral resource estimate.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6

doi: 10.1130/abs/2025AM-412427

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