Standard Lithium Ltd. announced a maiden lithium resource statement for its approximately 30,000 acre Project in the south-western region of Arkansas, USA. The maiden resource report includes 802,000 metric tonnes of lithium carbonate equivalent (LCE) at the Inferred Resource category. Combined with Standard Lithium’s other project in Southern Arkansas, this results in a total combined Arkansas lithium brine resource of 3,888,000 tonnes LCE. The TETRA Project lithium brine Inferred Resource, as reported, is contained within the Upper and Middle facies of the Smackover Formation, a Late Jurassic oolitic limestone aquifer system that underlies the entire Property. This brine resource is in an area where there is localised oil and gas production, and where brine is produced as a waste by-product of hydrocarbon extraction. The data used to estimate and model the resource were gathered from active and abandoned oil and gas production wells on or adjacent to the Property. The resource underlies a total of 807 separate brine leases and eight brine mineral deeds which form a patchwork across Columbia and Lafayette Counties in south-western Arkansas. The Property consists of 11,033 net hectares (27,262 net acres) leased by TETRA, and the resource estimate was only modelled for that footprint. The resource area is split into the northern and southern resource zones, where a fault system is interpreted to act as a divide between the two areas (although there is hydrogeological continuity in the resource zone across the fault system). In general, the Upper and Middle Smackover formations are slightly thinner, with lower lithium grades in the northern zone, and slightly thicker with higher lithium grades in the southern zone. The depth, shape, thickness and lateral extent of the Smackover Formation were mapped out in a 3D model using the following data: 2,444 wells drilled into the subsurface in the general TETRA Property area. Of these, 2,041 wells were deep enough (2,135 m, or 7,000 feet) to penetrate the Upper Smackover Formation; 104 wells had electric logs available within the TETRA Property that included the top of the Upper Smackover Formation; 32 wells had electric logs available within the TETRA Property that included the base of the Upper Smackover Formation; and 19 wells had electric logs available within the TETRA Property that included the base of the Middle Smackover Formation. In addition, hardcopy prints of 20 proprietary regional seismic lines totaling over 200 line-km (over 125 line-miles) were procured, scanned, rasterized and loaded into Kingdom® seismic and geological interpretation software. The porosity and permeability data used to characterize the Smackover Formation hydrological model included: Historical effective porosity measurements of more than 1,935 Smackover Formation core samples that yielded an average effective porosity of 14.3%; Historical permeability data that vary from <0.01 to >5,000 millidarcies (mD) with an average of 338 mD; 515 core plug samples from oil and gas wells within the Upper and Middle Smackover Formations at the TETRA Property were analysed for permeability and porosity and yielded an overall average permeability of 53.3 mD and a total porosity of 10.2%; and 3,194 Smackover Formation total porosity values based on LAS density/porosity logs from 29 wells within, and/or adjacent to, the TETRA Property that have an average total porosity of 9.2%. With respect to the resource estimation, a statistical review of the capped and declustered effective porosity measurements collected within the Upper and Middle Smackover formations resulted in average porosity values of 10.1% and 10.3% for the Upper and Middle Smackover formations, respectively.