Mount Cornish Tenement

Introduction

The Mount Cornish tenement (EL30242), located 20 km south of KGL’s Jervois Project within the East Arunta Orogenic Domain, covers approximately 88.6 km² following a reduction from its initial 180.32 km² in 2016. Acquired in 2014, the tenement has a history of exploration dating back to the 1970s but remains largely underexplored due to thick sedimentary cover. Reinterpretation of historical geophysical data has revealed anomalies suggesting potential for mineralisation, warranting targeted drilling to test depths beyond previous efforts.

Regional and Local Geology

The tenement lies within the East Arunta Orogenic Domain, a poly-deformed and metamorphosed terrain comprising Proterozoic clastic sediments, metavolcanics, calc-silicates, dolerite, mafic rocks, and granites. This region underwent significant high-grade metamorphism during the Paleoproterozoic Strangways Event, followed by further deformation during the Alice Springs Orogeny. These events resulted in amphibolite to granulite facies rocks, which dominate the area.

Locally, the Mount Cornish tenement encompasses a diverse range of lithologies. Paleoproterozoic metamorphics, including quartz-feldspathic-biotite gneiss, feldspathic quartzite, schist, and calc-silicates, are present alongside intrusive units such as the Jervois and Xanten granites, Attutra metagabbro, and Samarkand pegmatite. The surficial cover includes Quaternary sand, aeolian deposits, and tertiary saprolite. The geological complexity provides a favourable environment for potential mineralisation, although it poses challenges for exploration due to the thick sedimentary cover.

Figure 1. Location map of Mount Cornish and Jervois projects, showing satellite imagery and structural/fault system map.

Figure 2. Mt Cornish tenement surficial geological map, simplified from NTGS Jervois Range map 2019. Historical hole’s location. S-series holes were drilled in 1983 by Geopeko, and ARURAB-series holes were drilled in 1993 by Poseidon Exploration Limited.

Historical Exploration

Exploration of Mount Cornish spans several decades, beginning in the 1970s. Initial efforts focused on aeromagnetic surveys, radiometric surveys, and percussion drilling. While magnetite lenses were identified, they showed limited base metal potential. Drilling often failed to penetrate the thick sedimentary cover, and anomalies were inadequately tested. Poseidon’s exploration in the 1990s identified NNW-SSE magnetic features, but the area was ultimately deemed unprospective for significant mineralisation.

Post-2000 exploration included radiometric surveys and geophysical modelling. Arafura Resources identified uranium anomalies that were deemed uneconomic, while Minotaur Exploration’s surveys indicated tabular magnetic bodies at depths greater than 120 meters. However, ground EM surveys failed to identify massive sulphide conductors, leading to the tenement’s relinquishment. In 2014, KGL’s reinterpretation of historical geophysical data highlighted anomalies beneath the thick cover. Structural mapping suggested potential mineralising trends, but significant follow-up work remains.

Future Exploration Plan

Geophysical surveys have been the dominant exploration method at Mount Cornish, but inconsistencies in results highlight the need for advanced techniques. Modern 3D magnetic modelling and deeper EM surveys could provide a more accurate understanding of subsurface structures and targets. Testing these targets will require an RC drilling program designed to probe deeper than previous efforts.

Drilling should focus on anomalies identified by International Geoscience’s 2014 reinterpretation and Minotaur’s 2011 magnetic anomalies, particularly those coinciding with Petrocarb’s earlier findings. Recommended depths exceed 150 meters to account for deeper magnetic responses. Specific targets include areas with higher magnetic susceptibility readings and logged pyrite, such as S114-1.

Figure 3. Mount Cornish tenements was 57 blocks (180.33 sq.Km) initially in 2014, 29 of which were relinquished in 2016. Currently, contains 28 blocks (approximately 88.6 sq.Km).

Figure 4. Magnetic TMI map of mount Cornish and EM anomalies (white circles with black dot) identified by International Geoscience in 2014. Soil geochemistry showing copper concentrate in ppm. Elevated copper concentrate in the soil sample coincides with the EM anomalies.

Conclusion

Mount Cornish remains an underexplored tenement with promising geological and geophysical indicators. A focused exploration program leveraging modern tools and systematic fieldwork could unlock its mineral potential. Emphasis should be placed on anomalies identified through reinterpreted data and structural mapping. KGL retains the tenement while systematically testing these targets, this will position KGL for potential discoveries.