231-9 Lithium Enrichment in Alberta Basin Devonian Shales: Implications for Oilfield Brine Lithium Resources

Session: Critical Mineral Resources and Recovery in the Americas: Emerging Methods in Exploration and Sustainable Extraction (Posters)

Poster Booth No.: 279

Presenting Author:

Madigan Blake

Authors:

Blake, Madigan¹, Butler, Kristina², Morris, Natasha Jane³, Saha, Pritam⁴, Kennedy, Joanie⁵, Ibarra, Daniel Enrique⁶, Munk, Lee Ann⁷, Boutt, David⁸

Abstract:

Brine-hosted lithium resources are of increasing importance to the global energy industry as demand for lithium-ion batteries has grown exponentially. The Alberta Basin brines hosted in Devonian carbonate reservoirs are known to contain elevated lithium concentrations, yet heterogenous lithium concentrations confound resource exploration and valuation. Multiple hypotheses exist to conceptualize the lithium system, several of which include Devonian shales or fine-grained aluminosilicates as lithium sources. There is evidence that clay minerals play a critical role in the storage and release of lithium in brine-hosted systems. This study investigates the potential role of Alberta Basin Devonian shales as a source of lithium to the adjacent lithium-enriched carbonate-hosted brines.

We analyzed 22 shale core samples from Devonian units at variable depths (957–3,902 m) including major oxide concentrations (Al₂O₃, Fe₂O₃, K₂O, P₂O₅, MgO, CaO, Na₂O, MnO, TiO₂, Cr₂O₃), and trace elements (Li, Sr, Cu, Ba, Th, Ni, V, U) to examine paleoclimate, chemical weathering extent, and redox conditions. These characteristics were compared to lithium concentrations to investigate relationships between shale formation conditions and lithium enrichment.

Lithium concentrations in the Devonian shales (5–263 ppm Li) range from below to elevated with respect to average upper continental crust (~20 ppm). Six samples have notably high concentrations (>53 ppm). The most enriched shales are interbedded with Middle Devonian Prairie Evaporite, despite comparatively low lithium concentrations in the surrounding halite (average 17 ppm Li). Major and trace element analysis (Al, K, Na, Rb, Cs) suggests lithium ions are associated with fine-grained aluminosilicates. Al₂O₃–CaO* + Na₂O–K₂O ternary relationship indicates shales are dominantly illitic with minimal smectite content. Geochemical proxies for paleoenvironmental conditions (CIA, U/Th) suggest shales were deposited in a warm, humid environment under open marine (oxic) conditions, undergoing moderate chemical weathering.

Together these results indicate that the Devonian shales may serve as a source of lithium to the adjacent carbonate-hosted brines via diagenetic processes. Ongoing XRD analyses, lithium-leaching experiments, and isotopic (δ¹⁸O, δD, δ⁷Li, ⁸⁷Sr/⁸⁶Sr) investigations will further elucidate the role of shales in regional lithium enrichment mechanisms.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-10185

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