St Barbara Limited is pleased to report on the latest successful regional surface sampling and drilling program at southwest Tatau Island, Papua New Guinea (EL609). Highly anomalous gold results have been returned from the hand auger soil sampling program that extends the southwest Tatau Island +0.1 ppm gold in soil anomalies to an area covering 7.3 km2 . In addition, high grade gold in rock chip samples were returned from within the soil anomalies.
St Barbara Managing Director and CEO Andrew Strelein said:
“This first substantial regional exploration campaign at Tatau Island, the neighbouring island to Simberi, has rewarded us with multiple highly anomalous rock chip and soil samples that extend the anomalous areas around Mt Tiro and at Mt Siro – Seraror in particular. After focusing our attention in FY24 on the successful Simberi resource development and infill conversion program the team are now broadening their efforts to the regional program and following up opportunities identified in previous campaigns.”
“The Company believes that the presence of widespread alteration and elevated sulphides within the southwest Tatau Island supports the interpreted presence of a large hydrothermal system and demonstrates the exploration potential of the area. The fine tuning of our interpretation of the very large Simberi epithermal system is invaluable to the development of the thinking on exploration across EL609 and EL2462.”
Southwest Tatau Island Program
A regional exploration work program of surface sampling and RC drilling was completed over a portion of southwest Tatau Island between September 2024 and April 2025. The program included hand auger soil sampling, rock chip sampling, trenching and reconnaissance RC drilling.
The soil and rock chip sampling was conducted over an area of southwest Tatau Island measuring 6 km by 3.5 km:
- 300 regional hand auger soil samples were collected on a staggered grid at 200 m by 200 m spacing utilising a manual hand auger to provide a continuous soil profile down to a depth of between 1 m and 2.2 m depth (average 1.8 m). Soil profiles were documented and a sample taken for analysis from the upper portion of the ‘C’ horizon when intersected or the lower ‘B’ horizon when not reached, and
- 204 rock chip samples were collected from available outcrop, sub-crop or proximal float typically located in creeks, cliffs and access tracks.
The current epithermal gold deposits located within the Simberi Mine Lease 136, eastern Simberi Island, are all located within a +0.1 ppm gold in soil geochemical anomaly. The +0.1 ppm gold in soil anomalies on the neighbouring eastern Simberi Island that host the Simberi gold resources within ML136, covers an area of approximately 6.9 km2 and has an approximate 5 km by 2.5 km footprint. In comparison, the +0.1 ppm Au gold in soil anomalies on Tatau Island cover an area of 10.8 km2 , 7.3 km2 of which is located in southwest Tatau Island. The southwest Tatau Island +0.1 ppm gold in soil anomalies have an approximate 7 km by 3.5 km footprint. The presence of widespread alteration and percent sulphides recorded in southwest Tatau Island supports the presence of a large hydrothermal system and the exploration potential of the area. Significant areas of anomalous gold in soil and rock chip sampling remain to be tested with trenching and drilling as shown in Figures 6 and 7.
The gold assay results from the recent regional hand auger soil sampling program confirms and extends several +0.1 ppm gold in soil anomalies at southwest Tatau Island. Two main +0.1 ppm gold in soil anomalies located on southwest Tatau Island include the Mt Tiro area (measuring approximately 1.8 km x 0.8 km) and the Mt Siro - Seraror area (measuring approximately 1.4 km x 0.7 km).
The location of gold assay results from the recent soil and rock chip sampling program in the Mt Tiro area are shown in Figure 6 of this release. Several high gold-in-soil assay results (2.39 and 0.57 ppm Au) are located up to 500 m further southwest than the main areas of previous trenching and drilling. A 0.86 ppm Au in soil result was returned 250 m south of previous trenching and 500 m southeast of previous drilling.
The location of gold assay results from the recent soil and rock chip sampling program in the Mt Siro - Seraror area are shown in Figure 7 of this release. Several high gold-in-rock chip assay results (22.5, 2.0, 1.98 and 1.83 ppm Au) are located between 150 m and 450 m further north of previous historical trenching and drilling.
Trenching and reconnaissance RC drill holes were also completed during the campaign. A total of 22 trenches (TATTR289 to TATTR310) were completed covering 1,483 metres for 482 channel samples. The continuous, horizontal channel samples are collected on regular 2 m to 5 m intervals along exposure in excavator access tracks and creeks. A total of 17 RC drill holes (TTRC007 to TTRC023) were completed for 1,020 metres. Results for the channel sampling and RC drilling are expected in Q1 September FY26.
Proposed further work includes: 1) follow-up 200 m by 200 m extension to the soil sampling program to close out the plus +0.1 ppm Au soil anomalies and 100 m x 100 m infill soil sampling of selected +0.1 ppm Au soil anomalies; 2) upon receipt of the assay results for recent trench sampling and reconnaissance RC drilling, further trenching and subsequent RC drilling will be completed targeting the higher grade gold results.
The Company continues to work with the state nominee of PNG, Kumul Mineral Holdings Limited, towards an exploration joint venture agreement over EL609 and EL2462 .
