Lithium Energy (ASX:LEL) confirms 600m deep Half Graben Basin at White Plains lithium brine project in Utah

What does Lithium Energy’s passive seismic data reveal about the subsurface brine potential in the White Plains project area?

Lithium Energy Limited (ASX:LEL) has successfully completed a 38-kilometre passive seismic survey at its White Plains Lithium Brine Project in the state of Utah, United States. The survey identified a Half Graben Basin structure reaching depths of up to 600 metres, marking a key geophysical milestone in the Australian exploration company’s broader U.S. lithium strategy. The basin structure revealed is consistent with geological models that have hosted lithium-rich brines in other parts of the Basin and Range Province.

The passive seismic study, conducted along four east-west lines across the claim block, has enhanced subsurface understanding of a project area that lies within the historically significant Bonneville Basin. White Plains is situated within the Pilot Valley playa, a hypersaline salt flat on the Utah-Nevada border, an area widely regarded as prospective for lithium due to its endorheic hydrology and evaporite-rich sedimentary fill.

How does the Half Graben Basin structure support the geological case for lithium brine accumulation at White Plains?

Half Graben Basin structures are commonly associated with sedimentary infill zones adjacent to faulted bedrock, creating ideal conditions for fluid entrapment and concentration through tectonic extension. Lithium Energy’s seismic data suggest that brine-rich aquifers could be hosted in sandstone units and alluvial conglomerates deposited during the Miocene period, overlying Proterozoic and Paleozoic basement formations.

These sedimentary sequences, formed during the Basin and Range extension, are often closed basins that have historically accumulated brine through evaporation cycles. The passive seismic results not only confirm the presence of this favourable structure but also provide key data points for depth-to-basement estimates, which are critical in defining the lower boundary of potential brine-hosting zones.

The mapped depth of up to 600 metres is consistent with other lithium brine systems in the western United States, where economically viable brine deposits have been located within 300–700 metre depth intervals. Analysts monitoring the lithium sector have noted that such structural confirmation strengthens the exploration case, even before drill testing begins.

Why is passive seismic technology considered effective in lithium brine exploration, especially in Great Basin settings?

In arid, remote regions where conventional drilling is capital intensive, passive seismic technology offers a cost-efficient, non-invasive solution for delineating subsurface geological features. Lithium Energy employed TROMINO® instruments, which are capable of measuring ambient seismic noise with high resolution across multiple channels.

The seismic survey was conducted using 500-metre station spacing and 20-minute sampling durations per site. The gathered data provided continuous signal profiles across the 0.1 to 1,024 Hz range. These waveforms were then processed by geophysics consultants to identify stratigraphic boundaries and basement morphology.

Such surveys are particularly useful in early-stage brine exploration to define the scope of follow-up geophysical or geochemical campaigns. By focusing on identifying the basin geometry and depth, passive seismic methods enable junior explorers like Lithium Energy to prioritize high-potential areas and avoid unnecessary expenditure during initial drilling phases.

What are the planned next steps in Lithium Energy’s exploration program at White Plains following the seismic survey results?

With seismic interpretation now confirming a favourable Half Graben geometry, Lithium Energy has announced that it will proceed with a magnetotelluric (MT) survey across selected portions of the White Plains claim area. MT surveys are designed to measure natural variations in the Earth’s electromagnetic field and help map conductivity differences in the subsurface.

Hypersaline lithium brines, due to their high ionic content, typically exhibit strong conductivity contrasts relative to surrounding sediments. MT data will help delineate the vertical and lateral extent of conductive zones that could indicate brine saturation, offering a powerful tool for identifying future drill targets. This two-phase geophysical approach—passive seismic followed by MT—provides a comprehensive structural and hydrogeological map of the subsurface.

The MT survey will guide the placement of an initial drilling program aimed at confirming lithium concentrations in the brine aquifer, assessing hydrogeological parameters such as transmissivity and flow rate, and gathering samples for geochemical assays. Lithium Energy has signalled that this drilling campaign could pave the way for a maiden JORC-compliant resource estimate in the coming year.

How does the White Plains project compare to other lithium brine projects in the Basin and Range Province?

The White Plains project shares key geological traits with other well-known lithium brine districts in the Basin and Range Province, including Nevada’s Clayton Valley and Utah’s Paradox Basin. These regions are characterized by closed-basin hydrology, high evaporation rates, and basin-fill sedimentary sequences, all of which are conducive to lithium brine formation.

Situated in Pilot Valley, the White Plains claims lie within one of the Bonneville Basin’s salt pans. Historically, this area was part of Lake Bonneville, a Pleistocene-era pluvial lake that once covered vast swaths of western Utah. The retreat of this lake system left behind evaporitic deposits, saline crusts, and fine-grained clays known to act as lithium traps.

Lithium Energy holds approximately 6,150 hectares under tenure through 760 placer claims, offering significant scale and footprint. According to institutional observers, this land package, combined with the confirmed Half Graben Basin structure, positions the White Plains project as a potentially valuable U.S.-based lithium asset amid increasing federal emphasis on critical mineral independence.

What are the investment implications and institutional sentiment around Lithium Energy’s U.S. lithium strategy?

While Lithium Energy is still in the early exploration phase at White Plains and has not yet defined a resource, institutional investors are closely watching the company’s methodical progression. The strategic significance of the project is bolstered by its U.S. location, which aligns with the Biden-era Inflation Reduction Act’s critical minerals policies that remain active under the Trump administration due to bipartisan concern around lithium supply chains.

Investor sentiment appears cautiously optimistic, with analysts citing the company’s decision to adopt a modern, data-driven exploration approach as a positive sign. The successful integration of passive seismic and MT data could materially de-risk the project by refining drill targeting and maximizing the chance of intersecting lithium-rich aquifers.

Although no revenue is yet generated from the White Plains asset, the potential for fast-track development in a supportive jurisdiction could attract strategic partners or downstream EV battery manufacturers seeking secure lithium sources within North America.

What are the long-term development goals for the White Plains lithium brine project if drilling proves successful?

Should initial drill testing confirm lithium concentrations of commercial interest, Lithium Energy plans to transition the White Plains project into a defined exploration target and eventually into resource delineation under the JORC Code. Future stages would include hydrogeological pump testing, preliminary economic assessments (PEAs), and potential pilot plant operations.

Beyond resource definition, the scalability of brine operations typically hinges on aquifer recharge characteristics, evaporation rate modeling, and impurity profiles. In the long term, Lithium Energy is also expected to evaluate direct lithium extraction (DLE) technologies that could improve recovery efficiency while minimizing water consumption and surface footprint.

If all components align—from subsurface brine saturation to permitting and infrastructure—White Plains could emerge as a notable player in the North American lithium market, offering strategic supply diversity in a domain increasingly dominated by hard rock spodumene from Australia and brines from South America.