The exploration program at Salar de Rio Grande includes CS-AMT geophysical exploration, twin drilling and pumping tests. The purpose of the program is to better define the basin structure and aquifer system and to confirm historic drilling, assay and pumping data for the Rio Grande property.
Verification drilling was carried out utilizing a wireline triple tube core barrel system recovering HQ size core for geological logging and Relative Brine Release Capacity analysis. While drilling in the center of the salar in proximity to drill holes SRG-2017-22T and SRG-2017-18T, unconsolidated volcanic derived sands were encountered which prevented both holes drilling to the planned depth of 100m below surface, reaching 60m and 84.5m respectively. In some cases, it was deemed necessary to repeat drill holes in the top 20m to 50m below surface where either the packer equipment was inoperable or brine recoveries were negative with corresponding historical ADY data indicating positive brine samples at the particular down hole elevation. The packer sampling in the eight LSC twin holes was designed to replicate the intervals within the ADY drill holes and this was achieved to an acceptable level. The ADY drill holes were all terminated at approximately 50m below surface. A decision to extend the LSC drill holes to 100m was made to test the potential higher grade lithium mineralization at depth. This has proved successful as lithium mineralization down hole tends to increase in grade with depth.
As reported previously, interpretation of CS-AMT survey results indicate that the potential for lithium bearing formations extends to depths in excess of 500m below surface. Secondly, these interpreted results also indicate the presence of two deep seated depositional centers. The first is well developed in the northern section of the salar and is open ended both at depth below 500m and laterally to the north. The second depositional center is more centrally located. The 2018 drill program will investigate both these deep targets and is designed to deliver an upgraded NI 43-101 Mineral Resource.
On August 1, 2018, LSC announced that it received completed and positive seismic tomography results from its Rio Grande project. Five seismic lines totaling 41.73 line km were completed, three lines orientated in north/south direction and two lines orientated in east/west direction. The interpreted tomography results suggest the occurrence of lithologies suitable for the hosting of brine at depth. Deep targets have been identified for follow-up core drilling to sample brine and to determine the host lithologies' porosity. Drilling to commence in the near-term.