Exploration licence 5747 covers 955 square km located ~ 110 km north-east of Adelaide, on the eastern side of the Mount Lofty Ranges. It forms part of SeeSaw Resources “Bower Project” and forms a down-facing “horseshoe” shape that loops from...
Exploration licence 5747 covers 955 square km located ~ 110 km north-east of Adelaide, on the eastern side of the Mount Lofty Ranges. It forms part of SeeSaw Resources “Bower Project” and forms a down-facing “horseshoe” shape that loops from Craigie Plains in the east, north around Peep Hill and then forms a western flank running south through Hansborough to Dutton. Basement outcrop within the licence area is limited to Adelaidean sediments in the west. Geologically the area lies within the Adelaide Geosyncline, along the Nackara Arc, a tectonic belt that is host to many historical goldfields. The Nackara Arc was formed during the cessation of Delamerian Orogeny convergent plate tectonic deformation, and contains felsic, intermediate and mafic intrusions emplaced during a bimodal post-late kinematic magmatic event of Ordovician age. These igneous rocks are exposed in places, but largely are now buried under Tertiary and Quaternary Murray Basin sedimentary cover. The intrusions include the Bower and Black Hills intrusive bodies, which have been recognised in regional magnetic and gravity data. The Bower intrusion is a complex body with a granite core, but with smaller magnetic anomalies occurring at its edges identified as representing gabbros. The Black Hills intrusive complex is defined in the regional magnetic data and by previous explorers as being strongly magnetic, and it consists of differentiated bodies of intermediate-mafic-ultramafic composition. SeeSaw’s aim is to conduct greenfields exploration in the relatively underexplored Nackara Arc for skarn and intrusive-related copper and gold mineralisation associated with felsic, intermediate and mafic rocks that have intruded Adelaidean (Neo-Proterozoic) and Kanmantoo Group (Cambrian) metasediments. From doing a desktop review of historical exploration data, SeeSaw concluded that the Bower Granite has exploration potential for skarn and intrusive copper and gold mineralisation. The Bower area is considered prospective for skarn alteration, an idea that is supported by the presence of reactive rocks (limestones and carbonaceous rocks) having a structural architecture that would facilitate fluid movement. On-ground exploration throughout the year across the tenement involved structural mapping to identify potential settings for economic mineralisation. A number of areas with recognised mineralisation were visited and mapped, and reconnaissance planning for a drill program ensued. The western limb of the tenement was partially surrendered 20th February 2017, a 30% reduction in tenement size to 677 km2. During the second licence year to 21st February 2018, activities undertaken by SeeSaw included geological and structural interpretation, target generation and was followed up with the completion of an exploration drilling program across two potential prospects (Brownlow North & Bower, and Clivia). Open file high resolution aeromagnetic data is available across the tenement at various line spacings and quality and was used by SeeSaw to directly define target areas and to produce a solid geology interpretation for the area. Based on data compilation and review, SeeSaw believes that that the Bower Granite presents the same exploitation potential for Cu-Au skarn mineralisation as it does for intrusive related Cu-Au mineralisation. It was also noted that within the regional magnetics, where the Eastern Black Hill Intrusive (EBHI) has intruded the Cambrian Kanmantoo metasediments, the metasediments appear to bend around the EBHI creating “pressure shadows”. Such pressure shadow sites are prime locations for mineralisation, especially in reactive host rocks and/or re-activated extensional structures. The aim of the drill program was to conduct “greenfield” mineral exploration in the relatively underexplored Nackara Arc for various Cu mineralisation associated with felsic intermediate and mafic igneous intrusive rocks emplaced in Adelaidean (Neo-Proterozoic) and Cambrian metasediments. In April 2017, 5 RC/Diamond holes were drilled for 594.8 m including 23.2 m diamond core, with 89 samples submitted for geochemical analysis. Drilling was conducted with the assistance of the PACE Initiative Year 9 Discovery Drilling Project funds grant (DPY9-47) [See ENV13048 CNO:2039933]. Drilling at the Brownlow North & Bower Prospects targeted reactive host stratigraphy proximal to the Brownlow and Bower Intrusive for skarn and intrusive Cu-Au related mineralisation. Hole SAW002 on the Bower Prospect intersected basement at 148 m at a sharp erosional contact with weakly weathered – fresh basement. Cored basement comprises multi-phase igneous intrusive lithologies of fine-grained diorite, porphyritic diorite – granodiorite, and fine-medium grained adamellite – granite. Frequently observed complex intrusive contacts likely represent the stopping margins of a fractionating magmatic intrusion, with an early stage dioritic phase evolving through porphyritic diorite-granodiorite to later stage granitic phases. The mafic–intermediate intrusive rocks, especially porphyritic diorite – granodiorite, exhibit disequilibrium crystallisation textures e.g. corroded and embayed plagioclase feldspar porphyroblasts, bimodal grain size crowded phenocrysts, and zoned feldspar megacrysts with plagioclase cores (Na, Ca) and microcline rims (K). Hydrous alteration of feldspars and amphiboles is absent, and no hydrothermal alteration or veins are evident. The dioritic phases have enough magnetite present to explain the targeted magnetic anomaly. At the Brownlow North prospect, pre-Tertiary basement rocks were penetrated in hole SAW003 at 108 m downhole, with a sharp contact between lignitic clays (91-108 m) and strongly weathered shales, graduating to fresh rock at 129 m (base of oxidation). The cored basement lithology is a black-dark green, laminated pyritic shale interpreted as the Neoproterozoic Tapley Hill Formation. Pyrite content increases from 2-3% to ~5% on relict bedding traces, fractures and cleavage planes, with very minor carbonate alteration on tensional fractures. No mineralisation is present. Drilling at the Clivia Prospect was designed to test the interpreted pressure shadow north of the EBHI for its potential to act as a fluid pathway, and to assess any potential geochemical dispersion and alteration of the surround Kanmantoo metasediments. Holes SAW010 and SAW011 both entered metasediments beneath the Murray Basin cover sequence, however, hole SAW009 passed directly into a felsic adamellite - monzogranite intrusion beneath the cover, thus indicating a basement topographic high. The thickness of Recent and Tertiary cover varies from 39 to 101 m. The basement in hole SAW010 is a highly foliated – schistose micaceous metasedimentary rock, whereas in hole SAW011 it is a foliated to schistose micaceous and pyritic metasedimentary rock (phyllite – greywacke) – possibly an intermediate volcanoclastic (Cambrian). No significant mineralisation is present in these holes. During the third licence year to 21st February 2019, no on ground exploration work was carried out by SeeSaw. The company undertook a desktop studies, establishing a GIS database to consolidate and review historical exploration open file datasets. SeeSaw continued to review the previous years drilling program results and the structural review to identify further potential targets within the tenement. During licence year 4, exploration activities conducted included: • Desktop review of historical exploration and available GIS datasets for the planning of exploration activities. • Field exploration involving reconnaissance traverses and target site inspection were undertaken on several occasions throughout the year to provide context for potential economic mineralisation within the tenement. The areas of reported mineralisation and exploration drilling by previous parties were visited, including inspecting drill core and drill chips held at Mines Department facilities. • Discussions with several external mining companies and parties regarding potential Farm-In exploration agreements and draft proposals. • Discussions and meetings with landowners regarding exploration access and multiple land use, including renewable solar power projects. • Discussions with Energy Exploration and review of their Sedan coal exploration database, especially regarding secondary dispersion and enrichment of pathfinder elements from basement alteration or mineralisation. During licence year 5, exploration work completed included: • Further desktop reviews of existing geophysical and drilling data and reviews into reports pertaining to the tectonic history of the Nackara Arc and the Delamerian Orogeny including the age, style, and structural controls on Cu-Au mineralisation. • Geological interpretations were revised for the aeromagnetic dataset for the Cambro-Ordovician Stonefield and Brownlow Granites, Black Hills Intrusive Suite and volcanoclastic pile including the Normanville Group and Kanmantoo Group. Interpretations were ground truthed and allowed for the development of mineralisation model. • Several field reconnaissance traverse and site visits were conducted to provide better context for potential mineralisation within the tenement. • Further discussions were held to find a JV partner and land access discussions. During year 6 of the project on renewed EL 6694, exploration activities during the first year of the renewed tenement were limited due to several factors that included changes to the Mining Act that delayed the granting of the licence by 9 months, this in turn limited SeeSaw’s ability to recapitalise to support exploration as it did not legally own the licence. Activity was also limited due restrictions put in place due to COVID-19 which limited the availability of exploration services and contract geologists. Exploration activities were again restricted to desktop reviews, geological interpretation, field reconnaissance (regional geology/lithologies and type sections), discussion with potential JV partners and exploration access discussions. During year 7 of the project for the second and final annual report for EL 6694, from 22nd February 2022 to the surrender of the licence on 8th March 2023, SeeSaw reported that exploration activities were severely impacted and limited due to the government’s decision to suspend Terramin Resources’ “Bird in Hand” mining application which was seen to significantly increase the sovereign risk of investment in exploration and mining development. As such the company was limited in corporate activity to attract funding for exploration. Due to investor and shareholder concern, SeeSaw Resources surrendered EL 6694 and withdrew from the ADI Grant exploration program. The company completed further desktop reviews, with a focus on ADI priority targets. Collaborations with the Department for Energy and Mining and South Australian universities were undertaken on the Minex CRC Delamerian Project and age dating work. Limited reconnaissance field trips were undertaken.