Pantoro confirms very high-grade gold intersection at Lake Cowan

by Leena Thomas
Image: Pantoro Limited

Pantoro Limited (ASX: PNR) has reported very high-grade results including 8.1m @ 67.29 g/t Au from 78.6m downhole, from the maiden drilling campaign at the Sailfish prospect on Lake Cowan within the Norseman project, WA.

The company reported that drilling returned 8.1 m @ 67.29 g/t Au from 78.6 m down hole, including 0.7 m @ 521 g/t and 0.25 m @ 252g/t Au. PNR said that the 3.9 m of core loss within the intersection is assumed to be 0 g/t in calculation of the weighted average ore interval.

Other significant intercepts include 1.8 m @ 4.25 g/t Au, and 3.5 m @ 2.56g/t Au.

The company said that the results confirm historical intersection of 1.5 m @ 461.47 gt/Au, drilled by Western Mining in 1992, and highlight the huge exploration potential of the prospect.

Norseman project

The Norseman Gold Project is located in the Eastern Goldfields of Western Australia, at the southern end of the highly productive Norseman-Wiluna greenstone belt. The project lies approximately 725 km east of Perth, 200 km south of Kalgoorlie, and 200 km north of Esperance.

The project has a Mineral Resource of 4.4 million ounces of gold. Historically, the Norseman Gold Project areas have produced over 5.5 million ounces of gold since operations began in 1935, and is one of, if not the highest-grade fields within the Yilgarn Craton.

Pantoro Limited had acquired 50% of the Norseman Gold Project in July 2019. Pantoro is the manager of the unincorporated joint venture, and is responsible for defining and implementing work programs, and the day to day management of the operation.

The project comprises 146 near-contiguous mining tenements, most of which are pre-1994 Mining Leases which are free of native title.

Significant numerous tier 1 targets include Gladstone/Everlasting (open pit), Maybelle (open pit), Scotia (open pit/underground), Princess Royal/Slippers (open pit), Cobbler (open pit), OK (Underground), and Daisy South. There are also new high-potential targets within the Lake Cowan deposit, which has had minimal modern exploration.

High-grade historical results

The previous reconnaissance program by Western Mining in the early 1990’s had returned results including CWS2 1.5 m @ 461.47 g/t Au inc. 1 m @ 690 g/t Au from 77 m downhole and 0.1 m @ 290 g/t Au from 100.75 m downhole; CWS22 1.4 m @ 21.15 g/t Au from 137.4 m downhole; and CWS16 0.25 m @ 54 g/t Au from 96 m downhole and 1.35 m @ 8.73g/t Au from 114.65 m downhole.

New targets in Lake Cowan

Sailfish was defined as part of historic Western Mining programs, along with the Harlequin and Cobbler deposits with wide spaced diamond drilling conducted at the time.

Harlequin became a spectacular discovery in 1991 with mining ultimately producing approximately 800,000 ounces at 10 g/t Au.

Drilling at Lake Cowan

The company had commenced a preliminary evaluation by Surface Diamond drill sampling of the Sailfish prospect located on Lake Cowan at the at the Norseman gold project.

Pantoro reported that it has completed an initial eight hole diamond drill program on Lake Cowan. Drilling was designed to test the lode system perpendicular to the interpreted orientation.

The company reported that the initial program was undertaken following a period of extensive historical data review. Pantoro said that the historical data was compiled from drilling programs completed by Western Mining in the early 1990’s.

PNR said that as part of this review a number of historically drilled holes were re-logged with the assistance of Pantoro’s structural geological consultant – Model Earth.

High-grade results

The company said that the drilling below the lake cover has returned a number of encouraging results including a bonanza intersection in Hole SFDD20_005 drilled proximal to historic hole CWS2.

Significant results received to date include 8.1 m @ 67.29 g/t Au from 78.6 m downhole inc. 0.7 m @ 521 g/t and 0.25 m @ 252 g/t Au ( including 3.9 m of core loss assigned 0 g/t Au grade); 3.5 m @ 2.56 g/t Au from 64 m downhole inc. 0.3 m @ 26.2 g/t Au ( including 1.6 m of core loss assigned at 0 g/t Au grade); and 1.8 m @ 4.25 g/t Au inc 0.95 m @ 7.71 g/t Au from 171.45 m downhole.

The company said that Sailfish appears to be a shallow SE dipping lode system with orientations similar to the Harlequin mine to the South based on current drilling.

PNR reported that the mineralisation at Sailfish is hosted in both the hanging wall basalts, consistent with some of the multiple lodes at Harlequin, and also within the favourable Bluebird Gabbro – which hosts the 1.8 million ounce North Royal deposit which was probably the most prolific orebody mined at Norseman historically.

Latest updates

Pantoro said that as part of the lake exploration work that it is undertaking, review and reprocessing of the extensive geophysical datasets is underway. PNR said that this work is particularly focussed on the Gravity and Magnetic data in conjunction with the historic multi-element geochemical data.

The company said that additional diamond drilling is also currently underway on another lake anomaly testing another high priority target.

PNR said that similar to the maiden Sailfish program, the current program will further test an existing anomaly with encouraging historical reconnaissance results.

The company reported that due to the very high gold grades intersected in hole SFDD20_005 (which has been screen fire assayed), screen fire assay test work will be completed on the lower grade intersections, and it is planned to undertake larger diameter PQ diamond core testing, in an effort to improve core recovery.

What’s next?

PNR said that significant further work is required to establish if an economic deposit may eventuate. The company said that larger diameter PQ drilling is planned to infill and improve core recovery in the high-grade zones.

Management comments

Pantoro Managing Director Paul Cmrlec said: “These results from our initial eight diamond drillhole program at the Sailfish prospect on Lake Cowan highlights the immense exploration potential of the project, and in particular the likely presence of further very high grade mineralisation that Norseman has been known for over many decades.

Our exploration programs in these areas are in their very early stages and it is too early to speculate what the results may mean in the context of the broader project. Our geology team at Norseman continues to work with our key consultants to better understand the geometry and geological setting within the immediate area ahead of additional drilling.

We are also working with our drilling contractors to increase the drillhole diameter in order to maximise core recovery in our future programs.”