Thunder & Lightning //
Chi Coltrane - Thunder and lightning (1972) · Comments120.
The recent Lightning Ridge (combined 30.4m @ 2.2% Cu) and Thunder (48.6m @ 3% Cu) discoveries (see September 26, 2023, Aston Bay news release) continue to highlight the effectiveness of EM as a targeting tool and the correlation of EM anomalies with semi-massive and massive copper sulfides.
Two other high-priority EM targets were tested recently during the drilling program. In addition to drill hole SR23-55 described above, hole SR23-53 targeted a FLEM anomaly in the newly named Hailstone area beneath surficial copper gossans (Figure 4). The drill hole intersected four zones with minor chalcocite veining (<0.2% Cu) but is interpreted to have missed the targeted conductor. Although the conductor was modeled with low confidence due to its location on the edge of the survey loop, the presence of copper sulfides is encouraging. Additiona EM surveys will be completed to better constrain the target for follow-up drilling.
Five significant, fault-related copper prospects (Thunder, Lightning Ridge, 3500N, 2750N and 2200N Zones) have been identified to date in the area around the southern graben fault. All of these discoveries are located at or close to the surface and have only been tested to a depth of approximately 100 vertical metres.
Drilling has confirmed that high-grade copper sulfides in the southern area are characterized by broad EM anomalies with a localized stronger EM signature. A number of these local ‘bullseye’ features remain untested and have the potential to further expand the footprint of high-grade near-surface copper mineralization within this area (Figure 4). Significantly, the broader EM anomalies may represent a deeper zone of copper mineralization with much larger lateral extents, which are common features of sediment-hosted copper deposits.
Further exploration along strike of the vast fault network in the area will be designed to test both near-surface and deeper sediment-hosted copper mineralization. Approximately 10km of prospective structures have been identified in the southern graben area alone. Additional EM and gravity surveys are planned for the start of the 2024 season and will cover the Storm, Tornado, Blizzard, and Tempest prospect areas.
