Poseidon Nickel upgrades Nickel reserve at Silver Swan deposit by 106%

Poseidon Nickel Limited (ASX: POS) has announced highly encouraging updates on its Silver Swan and Black Swan deposits located ~50km north of Kalgoorlie in Western Australia.

The company reported that the updated Ore Reserve for Silver Swan achieved a 106% increase in contained nickel metal to 130,000t @ 5.2% Ni (6,800 Ni tonnes).

Updating on the Black Swan exploration, POS said that large electromagnetic (EM) anomaly consistent with Massive Sulphides was detected beneath Black Swan open pit and previously mined Gosling deposit. The company said that the drilling of the EM anomaly will commence immediately.

Poseidon reported that assays were also received from the recent RC program at Windarra project’s Crazy Diamond Prospect.

Significant intercepts include 5m @ 0.75% Ni from 12m (ex-sulphides) including 1m @ 1.38% (approx. 0.8m true width). The company reported anomalous gold mineralisation up to 0.5 g/t Au.

Silver Swan

The Silver Swan is a part of the Black Swan Project located approximately 600km east of Perth and 50km northeast of Kalgoorlie, Western Australia.

The Black Swan project comprises the Silver Swan underground mine, the Black Swan open pit, and the Black Swan 2.2Mtpa Concentrator with 191,400t of nickel metal in resource.

At Silver Swan, a total of 14 mineralised domains were interpreted, which include the Goose, Fledgling-Canard, Peking Duck and Tundra-Mute ore bodies.

Silver Swan ore reserve update

The company announced that Silver Swan Ore Reserve has been updated based on Mineral Resource that was announced to market on 5th August 2019.

Poseidon said that the Ore Reserve estimate, prepared by Mining Consultants, Entech Pty Ltd is based on the mining methods, designs, schedules, cost estimates, and modifying factors, which have been determined from a revision of the previous Silver Swan and Black Swan 2018 Feasibility Study.

POS said that the outcomes have been achieved as part of the ongoing derisking and restart studies being undertaken for Black Swan.

The company said that the Ore Reserve economics is based on a processing recovery of 92.5% for nickel, commercial offtake terms and a nickel price of A$22,335/t.

106% increase in contained Ni

The company announced that the Ore Reserve estimate for the Silver Swan underground nickel mine as of February 2020 is 130,000 tonnes of ore grading 5.2% Ni for a total of 6,800 tonnes of contained Ni metal.

This is an impressive 106% rise in contained nickel when compared to the 2017 estimate.

EM anomaly at Black Swan

POS reported that a DHEM survey was conducted on diamond hole PBSD002 drilled in 2019 sub-horizontally into the Black Swan deposit 900m below the Open Pit. The survey was managed and interpreted by Newexco.

The company said that the DHEM survey has resulted in a large, off-hole EM anomaly with a response consistent with massive sulphides.

POS noted that the anomaly is located 550m below and in the same stratigraphic location as the Gosling Massive Sulphide orebody. Gosling was mined in 2008 and produced 121,417 t @ 4.4 %Ni.

POS reported that the comparison of the Gosling EM response and the new anomaly by Newexco suggests that the source is larger and more conductive than historical EM surveys that found the Gosling deposit.

The company said that although this is at an early stage of interpretation, this anomaly is interpreted to be caused by a highly conductive source that may be greater than the areal extent of Gosling.

The company reported that the DHEM anomaly is considered to be a high-priority drill target due to its basal contact location (stratigraphically favourable position to be nickeliferous) and the clean, late-time EM response which is consistent with massive sulphides at Black Swan and Silver Swan.

Windarra exploration update

The Company announced that it has received the assays from the recent RC program at the Crazy Diamond Prospect near Windarra project, where both gold and nickel have been intersected.

The Crazy Diamond Prospect is the next komatiite channel to the north of Poseidon’s Cerberus Discovery.

The company reported that drill hole PNRC0309 striked nickel enrichment in a 5m zone 10m below surface.

PNRC0309 intersected 5m @ 0.75% Ni from 12m (ex-sulphides) including 1m @ 1.38% (approx. 0.8m true width). The intersection is interpreted to be at the base of the Upper Ultramafic, a subsequent komatiite flow to the Windarra Ultramafic.

Gold mineralisation

The company reported that an arsenic anomaly associated with hydrothermal veining within the basal chert and intruding felsics was also evident from the assays.

POS said that a small group of selected samples was resubmitted for gold resulting in 1m @ 0.51 g/t Au in PNRC0264 from 30m (1m true width) and 2m @ 0.45 g/t Au in PNRC0278 from 33m (2m true width).

Poseidon said that additional intersections >0.1 g/t Au also occur and are considered highly anomalous.

What’s next

The company reported that a staged approach to the drilling will be adopted to assess the EM anomaly at Black Swan.

POS said that plans are currently being finalised as a priority to drill-test the modelled conductor plate to ascertain if the conductor composition is nickel sulphide.

Poseidon said that in case the anomaly contains nickel sulphides, a second hole will be drilled to ascertain the dip and width of mineralization. The footwall parent hole will then be extended to 1000m depth and cased.

This program is anticipated to enable the majority of the zone of potential for massive sulphides between Gosling deposit and PBSD002 to be assessed.

Management comments

POS’s interim CEO, David Riekie said: “This healthy Silver Swan Reserve upgrade is an important and significant benefit from the ongoing derisking and restart studies on and around Black Swan operations north of Kalgoorlie.

The EM anomaly identified below the Black Swan open pit and previously mined Gosling deposit, offers some very exciting potential and is a focal point for a priority drilling program.

Collectively, these outcomes are important additions that are building on the certainties created from previous successful drilling, to allow Reserve status and upgrade, as well as highlighting potential within previously untested zones. The proximity and location of the anomaly is an exciting prospect.

The additional and ongoing successful exploration also extends to our Windarra tenements.”

Written By Jonathan Norris
Jonathan is a founder of Mining.com.au and has been covering the resources industry since 2018. With over 17 years experience in print, broadcast and online media, Jonathan has seen first hand the transformative effect of online niche media.