Global Geoscience Intercepts High-Grade Lithium-Boron Within and Beyond Existing Resource at Rhyolite Ridge in Nevada, USA

HIGHLIGHTS

• Initial results from current drilling program confirm additional high-grade lithium-boron mineralisation within the current Indicated and Inferred Mineral Resource of 393Mt at 1640 ppm lithium (Li) and 0.51% boron (B)
• Drilling further indicates strong lithium-boron mineralisation extends south of the current resource
• Intersections include:
  • 17m at 2153ppm Li and 1.18% B from 87m within a zone of:
    40m at 1975ppm Li and 0.53% B in drill hole SBH-19
  • 18m at 1718ppm Li and 1.83% B from 165m within a zone of:
    38m at 1706ppm Li and 0.92% B in drill hole SBH-20
  • 17m at 1856ppm Li and 1.74% B from 131m within a zone of:
    37m at 1876ppm Li and 0.85% B in drill hole SBH-21
  • 17m at 1805ppm Li and 1.95% B from 122m within a zone of:
    38m at 1885ppm Li and 0.89% B in drill hole SBH-22
• Further assay results are expected soon from additional infill and extensional drilling
• An updated Mineral Resource estimate will be completed in September 2017

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NORTH SYDNEY, Australia, Aug. 16, 2017 (GLOBE NEWSWIRE) -- Global Geoscience Limited (“Global” or the “Company”) (ASX:GSC) is pleased to announce initial results from the current drilling program at its 100%-owned Rhyolite Ridge Lithium-Boron Project (“Rhyolite Ridge” or the “Project”) in Nevada, USA.  Global is advancing Rhyolite Ridge and a Pre-Feasibility Study (“PFS”) for the Project is well underway.

The current 5,000m drilling program is designed to upgrade a portion of the current resource from Inferred to Indicated category. This drilling program will also test for extensions of shallow, high-grade lithium-boron mineralisation outside of the current resource, particularly to the south.
   
“The confidence gained from this drilling program to upgrade and extend the resource is just one of many work streams underway that are integral to the forthcoming Rhyolite Ridge PFS,” commented Bernard Rowe, Managing Director of Global. “The initial results not only confirm thick zones of consistent, flat-lying lithium-boron mineralization at the Project, but that it extends beyond its current defined resource.”

Significant intersections from the first eight drill holes of the current program are tabulated in the table below:

For comparison, the high-grade upper searlesite (Li-B) zone within the current Rhyolite Ridge Mineral Resource (totalling 393Mt at 1,640 ppm Li and 0.51% B) is included in the table below:

The most southerly drill holes (SBH-20, 28 and 29) in this program are likely to extend the current resource to the south. Cross-section 4184000N below shows that the drill holes outside of the current resource have intersected a thick section of the upper searlesite (Li-B) zone that extends to near surface. 

A photo accompanying this press release is available at http://www.globenewswire.com/NewsRoom/AttachmentNg/262ac3eb-9be4-42ec-9971-f7b94c2736e1

The host rock for the upper searlesite (Li-B) zone contains low amounts of clay with typically less than 20% carbonate minerals and more than 40% of the sodium borosilicate mineral searlesite.

The plan below shows the high-grade lithium-boron mineralisation is open to the south of section line 4,184,000N.

A photo accompanying this press release is available at http://www.globenewswire.com/NewsRoom/AttachmentNg/77ce6b17-95fb-427e-9e18-e40efc56a1a3

The Mineral Resource remains open to the north, south and east. Assay results from the most easterly drill holes (SBH-16 to 18) in the current drilling program indicate that:

• The high-grade upper lithium-boron zone has begun to come back closer to the surface, indicating that the maximum depth of this zone is <200m.
• Lithium grades are increasing and boron grades are decreasing to the east.

WORK PROGRAM IN PROGRESS

The September quarter work program will continue to focus on work required for the Rhyolite Ridge PFS including:

• Optimisation of flotation and acid-leach process steps;
• Production of a lithium-boron brine for crystallisation testwork;
• Production of boric acid, lithium sulphate and lithium carbonate;
• Drilling to upgrade the high-grade Li-B resource to Indicated Resource category;
• Updated resource estimate;
• Preliminary mining study including pit design; and
• Progress environmental, ground water and geotechnical studies.

ABOUT RHYOLITE RIDGE LITHIUM-BORON PROJECT

Global Geoscience’s (ASX:GSC) 100%-owned Rhyolite Ridge project is a large, shallow lithium-boron deposit located close to existing infrastructure in southern Nevada, USA. The project lies 25km west of Albermarle’s Silver Peak lithium mine and 340km from the Tesla Gigafactory near Reno. Rhyolite Ridge has the potential to become a strategic, long-life and low-cost source of lithium and boron. 

Lithium-boron mineralisation is hosted within two sedimentary basins located four kilometres apart: South Basin (9 km²) and North Basin (20 km²).  At South Basin, high-grade lithium-boron mineralisation occurs in 20m to 50m thick, sub-horizontal sedimentary layers. The upper-most layer is 20 to 30m thick and outcrops along the western margin of South Basin over a strike length of approximately 3km.

Drilling at South Basin has defined an Indicated and Inferred Resource of 3.4 million tonnes of lithium carbonate and 11.3 million tonnes of boric acid (393Mt at 0.9% Li₂CO₃ and 2.9% H₃BO₃) making it one of the largest lithium and boron deposits in North America. The resource is open in most directions and is likely to increase in size with additional drilling. 

The South Basin Resource has a high-grade lithium-boron zone of 65Mt at 1.0% Li₂CO₃ and 9.1% H₃BO₃ containing a total of 650,000 tonnes of lithium carbonate and 5.9 million tonnes of boric acid.  

The deposit is amenable to low-cost open pit mining methods and simple acid leaching with low acid consumption. A simple and low-cost flow-sheet is proposed to produce lithium carbonate and boric acid on-site.

Contacts

COMPLIANCE STATEMENT

The information in this report that relates to Exploration Results and Mineral Resources is based on information compiled by Bernard Rowe, a Competent Person who is a Member of the Australian Institute of Geoscientists. Bernard Rowe is an employee and Managing Director of Global Geoscience Ltd.  Bernard has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken 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 (“JORC Code”). Bernard Rowe consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.

Information in this report that relates to Mineral Resources is extracted from the announcement titled “Maiden Resource for South Basin at Nevada Lithium-Boron Project” released to the ASX on 10 October 2016.  The company confirms that it is not aware of any new information or data that materially affects the information included in the original market announcement and that all material assumptions and technical parameters underpinning the estimates in the relevant market announcement continue to apply and have not materially changed. The company confirms that the form and context in which the Competent Person’s findings are presented have not been materially modified from the original market announcement.

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