BRISBANE, Australia, Jan. 18, 2018 /CNW/ -- Orocobre Limited (ASX: ORE,TSX: ORL)("Orocobre" or "the Company") is pleased to provide an update on the brine sampling of diamond drill hole CAU15 in the Cauchari JV property located in Jujuy Province, Argentina.
The exploration program is being managed by JV partner Advantage Lithium Corp. ("Advantage Lithium") (TSX Venture: AAL) (OTCQX: AVLIF) who hold 50% of Cauchari, earning up to 75%. Orocobre owns 33% of Advantage Lithium's issued capital.
Drilling intersected extensive sandy sediments, confirming the NW Sector contains relatively high drainable porosity and permeability south from CAU07 through CAU16 to CAU15
The brine body intersected in CAU15 extends over >132 m vertically and is expected to continue below the base of sampling at 234.5 m
CAU15 brine averages 407 mg/l Lithium and 3,196 mg/l Potassium from 102-234.5 m depth, with a higher average grade of 475 mg/l Lithium and 3,662 mg/l Potassium from 174-234.5 m
Average Mg/Li ratio of 3.1:1, only slightly higher than previous holes CAU07 (2.3:1), and CAU16 (2.5:1) in the NW Sector – very positive for utilisation of conventional or other brine processes
Diamond drilling ongoing on holes CAU12 and CAU13 in the south of the SE Sector, to provide increased drilling density and geological information in this area. These holes are separated by 2 km, with CAU13 located 2 km southwest of CAU09
Preparing to drill diamond holes CAU17 and CAU18 in the NW sector for resource estimation
Pumping tests carried out on CAU08 and CAU11 will be reported as soon as assay results are available
NW SECTOR - CAU15 Drilling Results Drilling intersected an extensive sequence of sandy material, with coarse sandy gravel units in the last 20 m of the hole. Brine assays from 9 samples at an average sample spacing of 15 m returned an average of 407 mg/l Lithium and 3,196 mg/l Potassium over 132.5 m from a depth of 102 m to the base of sampling at 234.5 m, with the total hole depth 243.5 m. Higher grade brine in the deeper part of the hole averaged 475 mg/l Lithium and 3,662 mg/l Potassium from 174 to 234.5 m.
The brine mineralisation shows similarities to CAU16 and CAU07, where higher grade brine is present beneath brackish water and low grade brine that begins at surface. In CAU15 this low grade material extends to a depth of approximately 100 m below surface. Intersection of Li mineralised brine in CAU15 suggests brine mineralisation continues further south.
CAU15 is located approximately 6.5 km south of CAU16, for which results were released in November. The brine body defined to date extends some 12.5 km in the N-S direction between CAU07 and CAU15. Diamond core holes CAU07, CAU15 and CAU16 have all intersected relatively permeable sandy sediments that are expected to yield relatively high pumping rates from the NW Sector, which is very positive for future brine extraction.
Brine sampling was undertaken systematically at a nominal 12 m vertical interval using bailer sampling equipment, depending on the conditions encountered in the hole.
The Mg/Li ratio in all brine samples is low, averaging 3.1:1 across all the samples and 2.9:1 over the higher grade interval from 174-234.5 m. This confirms the suitability of the brine for conventional brine processing, as applied at the nearby Olaroz project.
Drill core samples from CAU15 will be sent to an experienced porosity laboratory in the United States, where they will be analysed for drainable porosity characteristics for use in the upcoming resource estimate.
NW SECTOR - CAU17 and CAU18 Drilling Preparations are underway for drilling of diamond holes CAU17 and CAU18 in the NW Sector to supplement holes drilled in 2017 for resource estimation.
SE SECTOR – Drilling and pumping activities CAU08 and CAU11 Pumping Test Results Initial pumping test results are imminent for hole CAU08, located in the center of the SE Sector, and CAU11, located further to the south. Results will be provided when they become available.
Diamond Drilling of CAU12 and CAU13 Diamond holes CAU12 and CAU13 commenced in December and drilling is continuing following the end of year shutdown period, with the holes expected to be finished around the end of January or early February. This diamond drilling will provide additional information on the distribution of sedimentary units in the SE Sector and will provide samples for laboratory analysis of porosity. Additional information will be provided as it becomes available.
Competent Persons Statement The information in this report that relates to exploration reporting at the Cauchari JV project has been prepared by Mr Murray Brooker. Murray Brooker is a geologist and hydrogeologist and is a Member of the Australian Institute of Geoscientists. Mr Brooker is an employee of Hydrominex Geoscience Pty Ltd and is independent of Orocobre. Murray has sufficient relevant experience to qualify as a competent person as defined in the 2012 edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves. He is also a "Qualified Person" as defined in NI 43-101. Murray Brooker consents to the inclusion in this announcement of this information in the form and context in which it appears.
About Orocobre Limited Orocobre Limited (Orocobre) is a dynamic global lithium carbonate supplier and an established producer of boron. Orocobre is dual listed on the Australia and Toronto Stock Exchanges (ASX: ORE), (TSE: ORL). Orocobre's operations include its Olaroz Lithium Facility in Northern Argentina, Borax Argentina, an established Argentine boron minerals and refined chemicals producer and a 35% interest in Advantage Lithium.