Mapping of closed-basin lithium-bearing brines using Magnetotellurics (MT)
Case study: Iconic Minerals - Bonnie Claire Lithium Project, Nevada, USA
Lithium is a critical component in the electrification of the world and investigation of these resources is only beginning. In the case of lithium bearing brines, the total concentration and thickness of these brines are an important control on the commercial viability of these deposits.
The Bonnie Claire Property is located within Sarcobatus Valley in southern Nevada. The project area, which is approximately 30 km by 20 km, consists of quartz-rich volcanic tuffs containing anomalous amounts of lithium that occur within and adjacent to the valley. Geochemical analysis of the local salt flats has yielded lithium values up to 340 ppm. The gravity low within the valley is 20 km long, and the current estimates of depth to basement rocks range from 600 to 1,200 meters. The area’s 74 km2 region has potential for brine systems and further sediment resources.
The MT Survey, conducted by Zonge International Inc. of Reno, Nevada
In 2016, a survey consisting of nine east-west lines for a total of 52.9 line-km (32.4 line-miles) was conducted. The dipole spacing was 200 meters (656 feet), and the resulting data quality was described as "excellent". The conductive material, which extends to approximately 350 meters depth, indicates a high TDS (total dissolved solids) fluid filled system. Subsequent drilling in the area, and borehole logging, highlighted the ability of MT to map and estimate the lateral extent of these brine-filled sediments. The modeled base of the conductor from the geophysics correlated very well with the subsequent drilling results. This 6 km basin, with lateral resolution of 100 meters, was surveyed for less than $150K. The reliability of the electrical section has been verified by drilling and the geophysical section will provide critical support for both future development and for the generation of funding for the project.
On February 27, 2023, Iconic Metals announced the production of marketable battery-grade lithium carbonate from the Bonnie Claire Deposit.