The upstream area for Phase One of the Zero Carbon Lithium™ Project comprises the “Lionheart” development area.
The Vulcan Energy Resources Ltd. announced in September 2024 it had signed an agreement to finalise the consolidation of its ownership of upstream Phase One lithium and renewable energy assets. This acquisition replaced a Joint Venture agreement and brine offtake agreement with Geox, and has now been completed with the Company acquiring 100% of the assets.
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Summary:
The Upper Rhine Valley Brine Field (URVBF) is part of the Upper Rhine Graben (URG). The roughly 020° orientated Cenozoic Upper Rhine URG in west-central Europe forms part of the European Cenozoic Rift System (ECRIS).
The URG can be subdivided into southern (Basel – Strasbourg), central (Strasbourg – Speyer) and northern (Speyer – Frankfurt) segments, each approximately 100 km long.
The focus of the Project in the URG is on aquifers associated with the Permo-carboniferous Rotliegend Group sandstone, the Triassic Buntsandstein Group sandstone, and the Middle Triassic Muschelkalk Formation, which is composed of carbonate sediments, collectively the ‘Permo-Triassic strata. The Permo-Triassic strata underly all Vulcan Property licences and are characterized as a laterally heterogeneous sandstone unit within a structurally complex rift basin. The Middle Triassic Muschelkalk succession, however, is only present from the Taro licence area towards the south in the URG.
The Rotliegend Group within the URG formed during the late stage of the Variscan Orogeny with local extension already happening. The Variscan Orogeny was accompanied by volcanism that led to the deposition of intrusive deposits into the basement, which is underlying the URG. Those intrusive deposits are believed to form an essential part of the lithium system. The actual rifting of the URG occurred during Cenozoic times. Hence, the fault system is comparably young.
The Lower Rotliegend is comprised of alluvial-fan/fan-delta to fluvial-dominated Carboniferous and Permian sedimentary rocks. The basin infill subsequently transitioned from fluvial dominated to alluvial and eolian depositional environments during Upper Buntsandstein times.
The Lower Triassic Buntsandstein Group is subdivided into the Lower, Middle and Upper Buntsandstein subgroups as defined by distinct progradational and retrogradational fluvial sedimentary cycles. The Buntsandstein Group aquifer domain is defined as a confined sandstone aquifer that occurs between the fine grained Upper Buntsandstein Group and the coarse-grained base of the Lower Buntsandstein.
The Middle Triassic Muschelkalk represents the marine sedimentation that succeeds the fluvial deposition of the Buntsandstein. It consists of argillaceous dolomites and limestones as it represents a marine transgression. Towards the top of the Muschelkalk, evaporitic sediments dominate.
The Upper Triassic Keuper is dominated by pelitic sediments and represents a marine regression which provides a top seal for the reservoirs of interest together with the pelitic dominated Tertiary overburden.
The Permo-Triassic strata that includes the Rotliegend, Buntsandstein, and Muschelkalk Groups as well as 100 m of the Variscan basement are the focus of the resource models for the Lionheart development area, and Ortenau. Only the Buntsandstein group strata have been considered for the Northern licence areas that include Mannheim, Ludwig, Therese, Flaggenturm/Fuchsmantel, and the western part of Kerner.
Brine aquifers within the Rotliegend Group and Buntsandstein Group are considered to have some degree of hydrogeological communication. This is particularly evident in zones with a high degree of faulting and fracturing in which fluid brine can flow throughout the Permo-Triassic strata and can also penetrate the underlying faulted, fractured and altered granitic basement and the overlying Muschelkalk zone. These fault/fracture zones generally contain hot brine and exhibit high fluid flow rates. Consequently, they are a prime target for geothermal development.
Historical and Vulcan-conducted recent geochemical analysis of the aquifer brine from the PermoTriassic strata shows the brine is enriched with lithium, which is very consistent both temporally and spatially within the reservoir. The geothermal wells represent potentially cost-effective access points to acquire deep, geothermally heated, lithium-enriched brine associated with the Permo-Triassic aquifers overlying the crystalline basement.
Dimensions
The geometry of the Permo-Triassic strata in the URV has a gentle northward dip at the southern end of the field (i.e., at the Ortenau licence area) which transitions to a south-east dip further northwards at the Taro licence area. The top and base surface elevations of the Buntsandstein Group under the URV licences are approximately from 2000 m (south) to 3800 m (north) subsea (m SS) with an average thickness range of 310 m in the north and 380 m in the south, up to 475m thick locally. The top and base surface elevations of the Rotliegend Group under the URV licences south of the Taro licence are approximately from 2200 m SS to 3300 m SS with an average thickness range of 120 m to 310 m, across the URV.