COPPER, ZINC & LEAD PROJECTS
EL 29579, EL 29580, EL 29581 & EL 29669, Northern Territory
Core’s previous drilling confirmed the 20 kilometre Big-J target zone has the geology, geophysics and indications of near-surface copper mineralisation consistent with KGL Resources’ neighbouring Jervois Copper Project on a larger exploration scale.
Core’s first pass shallow drilling program found visible copper mineralisation near-surface and over intersections several metres wide in a number of drill holes and elevated copper levels on all five traverses drilled across a 15km section of the Big-J target zone.
Much of the Big-J target geology is buried under a very shallow cover of sand and soil and the primary purpose of the drilling was to determine geology and the depth of this cover. Whilst the drilling determined that the cover was shallow, the number of holes that intersected copper mineralisation and the grade of that mineralisation far exceeded the Company’s expectations.
Core’s copper assays are comparable in magnitude with KGL’s nearby surface copper exploration results in and around KGL’s J-fold line of lode which hosts the Jervois Project, but represent a much larger area of prospective geology.
Previous explorers had disregarded the huge potential of his area of Bonya Metamorphics as earlier exploration and development activity has focused on nearby areas of outcropping mineralisation.
Given the encouragement of these excellent results, a range of drilling and exploration opportunities open up to Core to further prove up the copper potential and scale of Big-J.
Obvious large, untested 2,000m to 6,000m gaps within the 20km length of the Big-J are targets for infill reconnaissance drilling. In addition, Core anticipates follow-up deeper drilling to test the depth extensions of identified near surface copper mineralisation.
KGL’s nearby work has also shown the success of applying geophysics to find deeper deposits at Jervois, so Core intends to complement its near surface exploration with additional geophysics to aid drill targeting and interpretation.
YERELINA ZINC PROJECT
EL 5015, South Australia
Zinc assays from broad mineralised breccia zones drilled by Core during the 2016 reporting period indicate that the Company has possibly discovered a new sedimentary-hosted zinc system on the Yerelina Zinc Project, which covers a total area of 1,000km2 in northern South Australia.
At the Great Gladstone Prospect, a 17m intersection from 145m depth of mineralised breccia and veining averages a zinc plus lead grade of 1.4% and 19g/t silver and includes higher grade zones of 4m at 3% Zinc, 1% lead and 59g/t silver from 150-154m.
The 33m intersection (approximately true width) of oxidised breccias and veining at Big Hill Prospect, 5km to the east of Great Gladstone, also contained consistently elevated zinc levels. Due to the near-surface oxidation of base metals sulphides, zinc levels at Big Hill were lower and averaged 0.2% zinc over 33m from 14m-47m depth - YRDH005.
The mineralised zones intersected are located down dip of outcropping mineralised gossans. Surface channel sampling of these gossans at Great Gladstone and Big Hill returned significant zinc, lead and silver assays. The gossans are interpreted as the mineralised surface expression of a fault zones mapped at surface and by magnetics over 1km-3km.
Of the 38 samples taken along a 1km section of fault zone at Great Gladstone, 34 returned combined lead and zinc assays in excess of 1% and over 1g/t silver with the best assay at 14.7% zinc. Lead values peaked at 12.7% and silver at 567g/t.
Core’s analysis of modern satellite imagery and the Company’s detailed heli-borne magnetic and radiometric survey data have identified that historic workings at Great Gladstone, Big Hill and other prospects are hosted by a large-scale 3km x 8km system of repeated north/south regional structures.
Many sediment-hosted zinc deposits (e.g. Lennard Shelf in WA) have strong structural control or influence on mineralising fluid movement through the sedimentary package. Often this is associated with mineralised breccias and veining and alteration in fault zones and zones of shearing as observed at Yerelina.
Typically, the economic scale of these deposits is driven by stratiform (often flat lying) deposits proximal to the identified discordant mineralised structures /transport system.
The geology and system at Yerelina has potential to host large stratiform deposits in association within the known calcareous and reef limestone host facies within the Tapley Hill Formation proximal to drilled and also other known mineralised discordant structures.
BLUEYS AND INKHEART LEAD/SILVER PROJECT
EL 28136, EL 28029, EL 27709, EL 28940 & EL 30669, Northern Territory
Core received impressive silver and lead results in reverse circulation (RC) drilling at its Blueys and Inkheart Prospects in the Northern Territory.
Drill hole BLRC011 intersected 1m @ 1070 g/t Ag and 8.21% Pb from 24m down hole in a broader halo of 7m @ 166 g/t Ag and 1.27% Pb (Figure 13). Drill hole BLRC010 drilled from the same pad as BLRC011 intersected 2m @ 843 g/t Ag and 5.9% Pb in a broader halo of 17m @ 116 g/t Ag and 0.83% Pb.
Core’s RC drilling in 2014 intersected additional broad zones of silver and lead mineralisation including high grades up to 268g/t silver (Ag) and 8% lead at the nearby Inkheart Prospect in the NT .
The mineralised zone at Inkheart was intercepted consistently for at least 500m along strike and contained wide and high-grade intersections mostly within the host carbonates of the Bitter Springs Formation.
The mineralised zones at Inkheart are open to the north east, at depth and potentially to the south west.
The near-surface silver and lead mineralisation at the Blueys Silver Prospect is believed to
be enhanced by supergene processes with the majority of high grade mineralisation at the base of oxidation of the Bitter Spring Formation sediments. At depth, the epigenetic veins, mineralisation and broader alteration appear to have a primarily structurally controlled with some secondary influence by rock type.
The grade and continuity of mineralisation intersected by Core’s drilling at depth, along with growing confidence in a predictable exploration model for high grade silver lead mineralisation at Inkheart strengthen the potential for further success in this exploration province in the NT.
Core believes there is potential for further mineralisation over a much larger area within the target Bitter Springs Formation geology. This reinforces the tenement wide and regional potential of the Bitter Springs Formation for the discovery of economic precious and base-metal deposits .
MT FREELING BASE METAL PROJECT
EL 6038, South Australia
Core’s Mt Freeling Project is a northern extension to the Yerelina Project, covering three tenements over 1,106km2.
The Project hosts a geological setting similar to that of Yerelina, but includes Upper Adelaidean and Cambrian sequences.
The area also holds numerous historic base metals workings and prospects; however, very little historical base metals exploration has been undertaken as the focus on the area has predominately been on uranium, manganese and diamonds.
At the Ooloo Prospect, two parallel lodes were discovered in 1923, in the Late Adelaidean Billy Springs Formation. Irregular lenses and narrow discontinuous veins of galena-sphalerite-chalcopyrite-pyrite+/-covellite with quartz-limonite-ankerite/siderite-dolomite gangue which orthogonally cross-cut the host stratigraphic fabric.
A large gravity anomaly beneath workings was identified in 2012. Reprocessing of historic (1970’s) IP modelled two large resistive bodies: one under the workings and one larger (1.5km x 500m) to the south west of the mine. Drilling limited to only 9 shallow (35m depth) percussion holes drilled in 1971.
At the Mt Freeling Prospect, mineralisation occurs in well-defined gossanous fault breccias. Cauldron’s rock-chips were anomalous in Pb-Zn-Au-Cu-Bi-Mo-Sb-As-Sn over 1.6km strike-length fault zone within a 200m wide siderite alteration corridor. There are three styles of mineralisation including massive galena in veins up to 1m wide (refer rock chip assay table below)
A significant base-metal mineralising system being active in the Northern Flinders Ranges is supported by:
- An abundance of base-metal mineralisation and anomalism at surface throughout the Flinders Ranges,
- Located at the margin of a large NeoProterozoic Basin
- The observation of structurally controlled hydrothermal breccias,
- Carbonate-replacement and dolomitization of favourable host lithologies,
- The regional presence of diapirs and other perturbations in basin floor topography,
- Broad alteration halos about mineralised structures,
- Elevated path-finder element suites in surface sampling,
- Areas of mapped structural complexity (potentially related to basin development),
- The presence of elevated iron and manganese which are widely recognised as alteration halos related to SEDEX base-metal deposits.
NAPPERBY ADVANCED URANIUM PROJECT
EL 31449, South Australia
Core was the successful applicant and has been granted the tenement over the advanced Napperby Uranium Project in the NT (refer announcement 15/02/2017).
The Napperby tenement area was the subject of an internationally competitive tender process with Core adjudged to have the best financial and technical resources available to advance the project.
Mining consultants have been reviewing historic, detailed drilling information at Napperby to assess the potential to define a JORC 2012 Mineral Resource at Napperby.
Only half of the area of the much larger mineralised uranium zone defined earlier at Napperby
by Uranerz was drilled to define the scale and grade of mineralisation by Toro Energy Limited (ASX: TOE). Consequently, there remains obvious potential to substantially expand and increase the size of the Napperby Uranium Project.
Core has gained access to a Napperby Scoping Study prepared by Toro in 2009, including metallurgical testwork studies on bulk representative samples, which examined various conventional mining and processing options available at the time.
Core also inherits excellent project data that includes auger, sonic core and aircore drillholes (1,117 by TOE-DYL and 820 by Uranerz), downhole gamma and assay data, PFN (Prompt Fission Neutron) and disequilibrium data, airborne EM (Electro-Magnetics) and high-resolution magnetics/ radiometrics, gravity, and environmental monitoring data.
The extensive mineralised zone at Napperby occurs within 3 to 8 metres of the surface almost exclusively hosted by unconsolidated paleo channel sediments.
FITTON URANIUM PROJECT
EL 4569, South Australia
Core has previously made an outstanding discovery of shallow, high grade uranium on the 100% owned Fitton Project adjacent to Four Mile Uranium Mine.
Core’s exploration work and drilling at Fitton confirmed that:
- uranium mineralisation outcrops
- uranium mineralisation contains both thick and high-grade intersections
- uranium mineralisation extends to at least 150m downhole depth
- the mineralised structure is over 1km long
- exploration potential for repeated mineralised structures
Key drill intersections at Scott Lee Prospect, Fitton Project SA.
21m @ 384ppm (0.04%) U3O8 from 40m Inc. 6m @ 978ppm (0.10%) U3O8 from 54m
19m @ 487ppm (0.05%) U3O8 from 79m Inc. 6m @ 1,112ppm (0.11%) U3O8 from 89m
60m @ 482ppm (0.05%) U3O8 from 53m Inc. 35m @ 750ppm (0.08%) U3O8 from 53m Inc. 4m @ 3,100ppm (0.31%) U3O8 from 55m
75m @ 268ppm (0.03%) U3O8 from 82m Inc. 31m @ 452ppm (0.05%) U3O8 from 126m
Core’s 100% owned Fitton Project is located in a proven world-class uranium mining region, 500 kilometres north of Adelaide in South Australia and is located within 25km of three uranium mines.
- Beverley Mine (46Mlb U3O8 Resource 7.7Mt @ 0.27% (21,000T U3O8)
- Beverly North Mine (8.8Mlb U3O8 Resource 2.2Mt @ 0.18% (4,000T U3O8)
- Four Mile Mine (71Mlb U3O8 Resource 9.8Mt @ 0.33% (32,000T U3O8)