New South Wales Projects (SER 100%, NSW)
In 2018, the Geological Survey of NSW (GSNSW) identified five key regions as part of their involvement in the MinEx Cooperative Research Centre (MinEx CRC) National Drilling Initiative program. These regions are undercover extensions to known mineralised terranes and the focus areas for the next 10 years of the GSNSW involvement in the MinEx CRC. SER has now successfully secured a number of high-quality exploration projects that all were part of the NSW Mineral Allocation Areas (MAAs).
THE MUNDI PROJECT
The Mundi Project is a large-area, conceptual greenfield exploration project spanning over 1300km2 of the Curnamona Province, located approximately 115km NNW of Broken Hill. The Curnamona Province is a known iron oxide copper-gold (IOCG) mineral province with the potential for other mineral systems, such as Broken Hill Type Pb-Zn-Ag. The Project area has no known basement outcrop and very limited previous exploration.
The Mundi Project area targets the shallowest portion of the Curnamona Conductor (CC), a crustal-scale conductivity anomaly that has strong similarities to MT conductivity anomalies that have been interpreted to be associated with IOCG mineralisation in South Australia’s Gawler Craton (See ASX Ann. 21 September 2023).
In September SER undertook a 95-station MT survey to cover the shallowest portion of the interpreted CC anomaly, with stations spaced 400m apart along four east-west oriented lines 4km to 5.7km apart. All four lines were designed to cross both the Stanley Fault and interpreted CC anomaly, to resolve the relationship between the two features. Tensor MT data were recorded at all sites using four channel receivers recording two orthogonal electric field and two orthogonal magnetic field measurements per site. Broadband MT data were recorded overnight, resulting in 12 to 24 hours duration records with a frequency range of 10000Hz to 1000 seconds.
The MT survey was partially supported by a $50,000 grant from Round 5 of the NSW Government’s New Frontiers Exploration Program.
In November 2023, SER announced the advanced modelling of the MT data that was conducted by Professor Graham Heinson from the Electrical Earth Imaging Group at the University of Adelaide, a global leader in the use and interpretation of MT data for mineral exploration. Modelling revealed a large, high-intensity conductive anomaly, which appears to be centred on Lines C and D of the survey. Modelled resistivities in the core of the anomaly reach values of less than 0.1 ohm.m, which is mapping an unusually highly conductive feature.
The defined conductor is elongate in a north-south direction, at least 8km in length, and remains open to the south. The width of the conductor increases from ~5km at 1000m depth to more than 10km at 2000m, with a modelled base at ~2500m depth. The conductor shows a sharp north-south trending, near-vertical eastern boundary, interpreted to suggest a clear structural control, which approximately corresponds to an interpreted basement fault.
This survey was successful in confirming the presence of a highly conductive body at depth which extended beyond the planned survey area. A follow-up MT survey is now required to infill and extend the current survey coverage as well as a gravity survey to better understand basement geology and the extent, geometry and nature of a potential IOCG mineral system. SER expects to generate one or more targets for drill testing within the next 12 months.
EL9012 SOUTH COBAR
The South Cobar Project is located along the eastern margin of the Rast Trough at the southern end of the Cobar Basin. The project captures the northern and southern extensions of the Woorara fault, along strike from Eastern Metals’ (ASX: EMS) Brown’s Reef polymetallic deposit and the Achilles shear zone, hosting Australian Gold and Copper’s (ASX: AGC) Achilles 2 & 3 Prospects.
The most advanced Prospect at South Cobar is the Achilles 1 Cu-Au Prospect which was previously drilled by Western Plains Gold (WPG) in 2005. Drillhole DDH-A1-2 intersected a broad zone of intense hydrothermal alteration, with blebs of chalcopyrite and minor chalcocite, returning peak values of 0.33% Cu from 90m to 92m, within a 64m zone averaging 0.10% Cu, from 76m to 140m proximal to target. The second drill hole was abandoned at 184.1m and failed to reach basement.
SER has completed a follow-up 250-sample soil geochemical survey covering the Achilles 1 Prospect which revealed an 800m strike extent gold in soils anomaly, with a peak value of 17.4ppb Au. The anomaly lies along the Achilles shear where it is intersected by interpreted NW-trending fault structures and NE-trending magnetic lineaments. The anomaly is also associated with anomalous copper, lead, zinc and silver, as well as anomalous pathfinder chemistry, including arsenic, bismuth, molybdenum and tungsten, strongly suggesting the presence of a Cobar-style structurally controlled polymetallic copper-gold mineralising system.
The Garema project covers a 20km long undercover extension of the Parkes Fault Zone, recognised as a major controlling structure for orogenic gold mineralisation associated with the Middle Devonian Tabberabberan Orogeny in NSW, and is associated with significant gold mineralisation along its ~150km exposed length, from Alkane’s (ASX:ALK) >2 Moz Au Tomingley gold project to the north to the extensive historical underground workings at Wheogo Mountain, approximately 30km WNW of Grenfell, for which production is unknown.
The application area has seen little previous exploration, with the only significant on ground work being undertaken by Newcrest in the early 1990’s, with the shallow drilling of 13 RC holes, between 11m and 88m in depth which intersected very low level gold mineralisation in the basement. The area is also covered by a open file high-resolution (100m line spacing, 45m sensor height) aeromagnetic dataset, which was flown in 2011.
SER will compile and reinterpret the existing available data (in particular the aeromagnetics) across the area to define exploration targets for further detailed work. Follow up work will include detailed ground or drone geophysics, soil geochemistry and aircore drilling to map basement geology and identify geochemically anomalous areas. SER believes that Ultrafine+TM next gen soil geochemistry will be an effective tool to identify orogenic gold mineralisation and will utilise this technique. Priority targets will then be followed up through RC drilling.
The Nymagee project is within the South Cobar MAA, on the eastern margin of the the Siluro-Devonian Cobar Basin, overlying the approximately N-S trending Woorara Fault, which also intersects SER’s current EL9012, located 60km to the south. Basement outcrop within the application area is limited, comprising Devonian shallow marine sedimentary rocks of the Cobar Supergroup to the west, and Silurian Erimeran Granite to the east. A fault bounded package, interpreted to be Ordovician deep marine sandstone of the Abercrombie Group, does not outcrop in the application area.
The project has seen very little previous exploration, other than a handful of stream sediment samples and 30 shallow auger holes that were targeted on magnetic highs and intersected magnetic palaeochannel fill. Further to the south, the Woorara fault is associated with polymetallic Cobar-style mineralisation, most notably at Brown’s Reef, and SER considers this application area to be prospective for this style of mineralisation. This potential is supported by the results of the GSNSW-CSIRO Cobar hydrogeochemical study, published in 2020, which highlighted the area under application as anomalous for Ag, Pb, Zn, Cu and Co. There is also an apparent conductivity anomaly associated with the Woorara Fault on GSNSW AEM Line 10510, which warrants further investigation.