Coda Minerals Limited is planning to drill test Iron Oxide Copper Gold (IOCG) targets at its Elizabeth Creek Copper Project in South Australia’s world-class mining jurisdiction, the Gawler Craton. It will be the first drill programme by Coda targeting IOCG mineralisation at Elizabeth Creek.
The Elizabeth Creek Copper Project is centred approximately 35 kilometres southeast of Woomera and 135 kilometres northwest of Port Augusta.
Elizabeth Creek is considered to be highly prospective for IOCG deposits. Based upon the results of an extended targeted exercise resulting in the identification of multiple areas of high IOCG prospectivity, Coda has prioritised two of its prospective IOCG targets for drill testing in the second quarter of 2021.
Some of the largest and most economically significant mineral deposits in Australia fall into the category of IOCG. These deposits are characterised by elevated copper and gold, and a significant iron oxide (both haematite and magnetite) component in the gangue, typically deposited in breccias located within the basement complex. Elizabeth Creek is located in the Eastern Gawler Craton and is in close proximity to significant IOCG discoveries including Olympic Dam, Carrapateena, and Oak Dam West. IOCG discoveries in the Eastern Gawler are often characterised by their large scale, depth and valuable co-products.
Emmie Bluff Deeps IOCG target
In a separate diamond drilling campaign, Coda is currently targeting shallower Zambian style copper-cobalt mineralisation at Emmie Bluff.
According to the company, assays have now been received from the laboratory and an update on drill results will be released imminently. Indicated Mineral Resources have previously been announced for the MG14 and Windabout copper-cobalt deposits .
According to the company, the Emmie Bluff Deeps IOCG target is defined by a series of coincident and semi-coincident gravity and magnetic anomalies in the north-west of Coda’s tenure, adjacent to its Zambian-style, sediment-hosted copper (Cu) – cobalt (Co) prospect at Emmie Bluff, and roughly 16 kilometres from BHP’s recent discovery at Oak Dam West.
A large IOCG-style mineralised and altered system, hosted by brecciated metasediments in the basement rocks, was identified by historical drilling undertaken by Mt Isa Mines and Noranda in the 1990s.
Evidence for the system includes large intersections of copper mineralisation (examples including 104 metres at 0.27 per cent Cu in historic hole SAE 6, extensive brecciation and magnetite and haematite alteration (including bands of steely haematite up to several metres thick).
Coda’s planned drillhole will test an area of coincident high gravity anomalism and low magnetic anomalism, seeking a copper and haematite rich but magnetite poor core of a broader IOCG system.
The company has advised that the geophysical signature is most consistent with that of the Prominent Hill copper-gold-uranium deposit currently being mined by Oz Minerals.
It is also consistent with, to varying degrees, to geophysical signatures of other large IOCG mineralised systems in the Olympic Domain/Eastern Gawler Craton, including that of the Olympic Dam deposit, which hosts Australia’s largest underground mine.
The vertical diamond drill hole is planned to be approximately 1,200 metres deep. It will be collared approximately 1.5 kilometres west-south-west of the shallower drilling currently exploring for sediment-hosted copper at Coda’s Emmie Bluff Exploration Target .
The drillhole is also located 500 metres west of historic hole MGD 55, which encountered zones of economic copper-gold mineralisation, with a best-reported intersection of 7 metres at 2.17 per cent Cu and 0.47 grams per tonne (g/t) of gold (Au) from 974 metres.
Coda interprets the mineralisation in these intersections as related to fault structures carrying mineralising fluids from a high-grade core, which the proposed hole is designed to test.
Elaine IOCG Target
Coda outlines that the Elaine IOCG prospect (centred around 42 kilometres southeast of Woomera) is characterised by a broad, triangular gravity high, and several coincident, discrete NE/SW trending circular/oval-shaped magnetic highs.
These geophysical anomalies are positioned immediately east of a large NE/SW trending fault identifiable in gravity data which may have served as a lithospheric scale fluid pathway for copper-gold mineralisation.
Historical deep IOCG drilling at Elaine targeted areas of coincident magnetic and gravity anomalism. First drilled to depth in 1980, and followed up in 1981/82 and 2000/01, drilling has consistently encountered copper-gold mineralised metavolcanics and strong IOCG-style alteration, including chlorite, epidote, magnetite, and pyrite.
Coda advises that ‘red rock alteration’, the result of the intense hematitisation typical of IOCG mineralised systems, is pervasive and often intense, and accompanied by varying degrees of brecciation, which aids the mineralising process. The company interprets the Elaine IOCG prospect as a large scale hydrothermal system within which copper has preferentially deposited in areas where temperature and oxidising conditions promoted the formation of haematite rather than magnetite.
A second drillhole has been planned to test the Elaine IOCG target immediately following the completion of work at Emmie Bluff Deeps drillhole.
This hole is also anticipated to be approximately 1,200 metres deep and will be collared approximately 1 kilometre south of historic hole PY 3, which encountered elevated copper and extensive IOCG-style alteration 1,036 – 1,232 metres.
Coda is currently seeking support from the South Australian Government’s Accelerated Discovery Initiative for the proposed Elaine drillhole .
Coda has submitted an EPEPR and is awaiting approval from the South Australian Government to commence drilling. A heritage survey with the local traditional owners, the Kokatha people, will be undertaken this month as part of this process.
Assuming approvals are provided, drilling is expected to commence at Emmie Bluff Deeps in late April to early May 2021, with both holes completed before the end of Q2 2021.
 See announcement on 26 October 2020 – Confirmation Statements – JORC.
 46 – 77 MT at 0.5 – 2.3 per cent CuEq. The Company notes that the potential grade and tonnage is conceptual in nature and there has been insufficient exploration to estimate a Mineral Resource and it is uncertain if further exploration will result in the estimation of a Mineral Resource. Please see ASX Announcement “Confirmation Statements (JORC)” (Confirmation of Exploration Target & Mineral Resource and Ore Reserve Statement), released to the ASX on 23rd October 2020, for full details and Competent Person’s Statement. Cu Eq = Cu % + (Co ppm*0.0012). Please see Coda Announcement “Appendix to the Annual Report 2020 – Mineral Resource and Ore Reserve Statement”, released 31/07/2020, available at https://www.codaminerals.com/wpcontent/uploads/2020/08/Coda_Announcement_Resource-and-Reserve-statement-2020_Typeset.pdf for derivation.
 Drilling at Elaine will be undertaken if Coda is successful in receiving the Accelerated Discovery Initiative (ADI) grant, but the grant is not necessarily required for drilling to take place. Coda’s board will make a final decision regarding the Elaine drill hole following confirmation of the status of the grant (due to be announced on 1st of April 2021).