Pursuit Minerals Ltd (ASX: PUR) has received significant results identifying multiple zones highly prospective for Lithium enriched brine from a Transient Electromagnetic (TEM) Geophysical survey at the Rio Grande Sur Project in Salta, Argentina.
The results of the TEM survey have continued in line with expectations that the Rio Grande Sur Project has potential to host a significant resource of Lithium brine. Pursuit is now focused on our maiden drilling campaign to define this resource as we await the environmental permits,” Managing Director and CEO, Aaron Revelle, said.
“The TEM data has outlined multiple 100m thick low resistivity (high conductivity) layers from approximately 150m to 300m depth underlying various tenements. These layers are below the current Canadian National Instrument 43-101 (NI43-101) Inferred Resource drilling which extended to 100m. The data additionally suggests that the material deeper than 250m is conductive and will also be considered prospective for future lithium brine exploration.”
Rio Grande Sur Project
The Rio Grande Salar hosts an Inferred Resource of 2.1 million tonnes LCE at an average grade of 370mg/Li to a depth of 100m reported as part of an existing NI43-101 report (LSC Lithium Corporation of Canada, 2018). CS-AMT surveys have identified Lithium enriched brines to a depth of 500m, and planned drilling to this depth is expected to significantly increase the resource. A portion of Pursuit’s Rio Grande Sur tenements (~3,000ha) cover a section of this resource.
Pursuit holds five tenements collectively known as the Rio Grande Sur Project that are prospective for lithium located west of Salta, Argentina. The five tenements cover approximately 9,233 hectares.
TEM Survey Results
Quantec collected data using their internally developed Transient Electromagnetic (TEM) field procedure. A series of TEM profiles were measured at the Rio Grande Sur Project tenements using a moving-loop method in which the receiver coil was located at the centre of a square, a single-turn transmission loop of 200m x 200m established and readings taken at one km intervals.
Four readings were acquired from each station with 15 second integration, stacked and averaged to assess data scatter and improve repeatability of measurements. The TEM system was calibrated by Quantec prior to commencement of the survey. All digital data was inspected daily by the survey crew and the company’s consulting geophysicist. No bad data was noted, and no lines were required to be re-sampled.
A total of 150 soundings were collected along 24 profiles in 4 tenements: Sal Rio I; Sal Rio II; Maria Magdelena; and Isabel Segunda.
Data was processed using several software packages (Geonics PROTEM W, Geonics Protix64, Geonics USFXLT and Interpex IX1Dv3.60) in order to establish the best inversion model (1D model) and to estimate the depth, thickness and resistivity of individual layers, specifically to identify discrete layers with low resistivity (high conductivity).
Data was then interpreted between stations to develop 3-dimensional models of the stratigraphy for each tenement to facilitate visual interpretation and correlation with known geology, and ultimately to guide the location of future exploration drill holes.
The TEM data has outlined an approximately 100m thick low resistivity (high conductivity) layer from approximately 100m to 250m depth underlying the tenement. This high conductivity layer is considered highly prospective for future exploration activities. Resolution of the TEM data below the identified high conductivity layer is complicated by the extreme low resistivity of the layer, which can reduce the accuracy of the physical and electrical property data collected for the material below 250m. However, the available data suggests that the material deeper then 250m is conductive and will also be considered prospective for future lithium brine exploration.
