Reviewed by Alex SmithApr 12 2022
Arena Minerals Inc. declared the completion of its first diamond drill hole (DD-02) at the Sal de la Puna Project (SDLP Project), which is located in Argentina’s Pastos Grandes basin.
Image Credit: Shutterstock.com/ Myfotoprom
The diamond drill hole, which was drilled on the Almafuerte claim, bisected a continuous brine column from 140 m to 646 m. The total amount of lithium (Li) in the sampled brine column was 496 milligrams per liter (mg/l).
Between 334 and 634 m downhole, an uninterrupted gravel aquifer was encountered, indicating the thickest gravel sequence drilled in the basin. At 550 m below the surface, the gravel aquifer averaged 503 mg/l Li, with grades as high as 557 mg/l Li.
Gravel and sand aquifers usually have high flow rates and effective porosity values, resulting in highly productive wells. DD-02 was finished as an observation well with a 2-inch diameter blank and screened PVC casing drilled to a depth of 450 m.
This first drill hole completed by Arena exceeds our expectations. The coarse gravel aquifer, where higher flow rates are typically found, appears to be thicker in our end of the Pastos Grandes basin with high grade lithium values and favorable geochemistry. We kept the drill turning past our target depth to determine the total thickness of this gravel sequence; however, the brine column remains open at depth for future potential resource expansion.
William Randall, President & CEO, Arena Minerals Inc.
William Randall adds, “We have now mobilized an additional drill rig to ensure we meet our development timelines.”
In DD-2, depth-specific brine sampling was carried out by using double and simple packer sampling systems across the entire brine column. Magnesium to lithium ratios of 4.5 to 1 and sulfate to lithium ratios of 15 to 1 were found on average in the brine column.
In addition to excellent lithium grades, we are very pleased with the brine geochemistry. The magnesium and sulfate ratios are within those currently used in our pilot facilities giving us great confidence that our objective of producing technical grade lithium chloride (6% Li) is achievable from the drilled aquifers.
Eduardo Morales, Executive Chairman, Arena Minerals Inc.
Mobilization of Two Additional Drills
Two additional drill rigs have also been mobilized to the site, according to the company. On the Graciela claim, one diamond drill rig is currently set up at DD-01, with a target depth of 550 m. If favorable lithologies are discovered, as was the case in DD-02 in the adjacent Almafuerte claim, the hole’s depth may be increased.
In three weeks, a second rotary drill will arrive in Almafuerte to drill a production well (P-1) 15 m away from DD-02. The well will be drilled to a depth of 450 m, to test the productive capabilities of the gravel aquifer intersected in DD-02 by conducting pumping tests with the nearby DD-02 serving as a monitoring well.
Arena is managing the drilling program for Sal de la Puna Holdings Ltd., a joint venture between Arena (65%) and Ganfeng New Energy Technology Development (Suzhou) Co., Ltd. (35%).
The drill program consists of 3,000 m and is concentrated on the Almafuerte and Graciela blocks, which border Lithium America’s Pastos Grandes project to the south and south-east, with the goal of both increasing the category of the current resource and expanding the SDLP Project’s resource base.
The Company and Atacama Water consultants collaborated to design and supervise the drill program.
For lithium multi-element Induction Coupled Plasma Spectroscopy analysis, all brine samples have been sent to SGS Laboratories in Salta, Argentina, an independent and wholly international accredited laboratory. Arena follows a strict Quality Assurance and Quality Control program that includes at least 10% duplicates, blanks and standards in every sample shipment.