Data release - as updated [made at SA Director of Mines' discretion] : Commonwealth Hill area (the Eaglehawk Joint Venture Project). Annual reports for the period 22/6/2012 to 21/6/2017.
Published: 29 Aug 1917 Created: 12 Nov 2024 Revised: 12 Nov 2024

An area centred ~115 km south-west of Coober Pedy is being explored for possible economic buried precious and/or base metal mineralisation (including iron ore) that may exist in predominantly buried Archaean or younger Proterozoic basement rocks,...

An area centred ~115 km south-west of Coober Pedy is being explored for possible economic buried precious and/or base metal mineralisation (including iron ore) that may exist in predominantly buried Archaean or younger Proterozoic basement rocks, as well as for any secondary, sediment-hosted uranium occurrences in Mesozoic cover strata. With respect to the latter, occurrences of highly silicified, coarse quartz sandstones and conglomeratic units crop out over most of the area and in the past have largely been identified as Tertiary silcrete, but now it is thought that they most likely represent basal units of the Jurassic Algebuckina Formation which unconformably overly basement units of the Archaean Mulgathing Complex. There is an additional possibility that they may be misinterpreted highly silicified units from the Cretaceous Cadna-owie Formation, including the Mount Anna Sandstone, or perhaps from the younger Cretaceous Bulldog Shale. No field work was carried out during the first licence year, while a grant of on-ground access into the Woomera Prohibited Area (WPA) was sought. Activities were confined to making desktop prospectivity studies and compiling available geophysical and remote sensing data. Mincor's initial application to the Australian Commonwealth Government for grant of a Deed of Access was declined due to the Moratorium on conducting mineral exploration within the WPA: however, the Moratorium was lifted in October 2012, so in November 2012 Mincor submitted a second application for grant of a Deed of Access, which was subsequently provided on 4/6/2013. It was intended to follow-up previously identified inferred IOCG - prone geophysical anomalies with detailed ground gravity and ground magnetic surveys, to validate and verify target locations. Surface calcrete geochemical sampling would likely be conducted across areas of geophysical anomalism and where historic surface sampling had identified anomalous geochemistry. Specifically, Apollo aimed soon to follow-up on limited drilling conducted by Minotaur (1997) and Redport (2002) at the Eaglehawk and Eaglehawk North prospects. An airborne electromagnetic survey was proposed to be carried out over EL 4932 and over several surrounding exploration licences that are currently also being explored by Apollo. During licence Year 2, Apollo commenced exploration by conducting field geological mapping and surface geochemical calcrete sampling, focussing primarily on the Bundi prospect situated on the eastern side of the Commonwealth Hill trig station (which extends onto the adjacent EL 5074). 42 calcrete samples taken over a 200 m x 200 m prospect grid and 7 grab rock chip samples of igneous rock and ironstone metasedimentary outcrops were laboratory assayed. Subdued copper anomalism was evident across the south-eastern part of the sampling grid, where float of highly weathered mafic and intermediate igneous bedrock occurs on the surface of a sandy loam regolith. Next, follow-up ground based geophysical surveys were acquired here in September 2013 and March 2014, including trial single traverses of magnetotelluric (MT), audio frequency magnetotelluric (AMT) and dipole-dipole induced polarisation (IP) readings which were intended to test for conductivity anomalies that might be caused by buried sulphide bearing units. Preliminary data processing/inversion results suggested that some conductive features exist at Bundi. A detailed and semi-regional ground gravity survey was acquired over the eastern part of EL 4932 in March 2014. A northern grid coverage comprised 476 stations spaced at 300 m intervals along east-west lines 300 m apart. Within this grid, a further 473 infill stations were read at 150 m x 150 m intervals to obtain detailed information for the Bundi prospect. A much more extensive and connected southern grid comprised 1744 readings made at 300 m station spacings along east-west lines spaced 300 m apart. Preliminary processed images of the gravity data were prepared. A rotary air blast (RAB) bedrock drilling campaign of 274 shallow vertical open holes with a total penetration of 1139.5 m was performed within the north-eastern part of the licence area where Native Title aboriginal heritage clearances had been obtained. Laboratory assaying of bottom-of-hole drill cuttings samples for a 35-element analyte suite revealed a north-eastwards trending copper anomaly which in part is related to the Bundi prospect surface calcrete anomaly. A PACE 2020 Geochronology collaboration project was approved by DMITRE in 2013 to date outcrop samples of inferred Gawler Range Volcanic (GRV) units mapped by the licensee, to help conceptually with resolving their possible local IOCG mineralisation potential. For the final results of this research work, see RB 2015/00003 re. Project PGC03-11. During 2013, the licensee decided to further expedite the geochronology aspect of its exploration programme through sending out another suite of rock samples for analysis by the CODES - ARC Centre of Excellence in Ore Deposits facility at the University of Tasmania. Age dating there was conducted on individual zircon grains extracted from each sample by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) using U(Th)-Pb isotope probing. The alternate dating results obtained from the nine samples which were taken from EL 4932 and sent to CODES were too widespread in ages to give any confidence about the petrogenetic integrity of these samples, and thus were deemed to be inconclusive [ for advice about this third party interpretation, please contact Anthony Reid at GSSA ]. The licensee had been hoping to obtain dating evidence to support its working concept of the IOCG-U prospective GRV extrusive rocks and related Hiltaba Suite granites occurring much further north than is shown by the SA Government's current mapping information on the Woorong and Carnding 100K geological map sheets. During licence Year 3, Apollo Minerals drill tested several targets, that were largely density anomalies identified from its earlier gravity survey which appeared to be slightly offset from aeromagnetic highs and were regarded as having IOCG potential. Between mid-September and early October 2014, and in May 2015, a total of 9 inclined RC holes for 1512.8 m were drilled, hole 14NB001 having a 112.1 m long HQ/NQ diamond cored tail commencing at 59.7 m downhole depth. Assaying of 416 composite drill samples did not reveal any significant copper or gold mineralisation, but slightly anomalous iron, titanium and phosphorus values were returned from holes at the Boulder and Claypan prospects, which appeared to originate in mafic units carrying magnetite, ilmenite and apatite. 55 selected representative samples of the different basement lithologies drilled, as well as a few samples of ?nearby outcrops, were submitted for petrographic examination. The rock descriptions, plus their whole rock chemistry data, together suggest that the titanium primarily resides in magmatic titanomagnetite. A QEMSCAN analysis which was performed on 5 selected samples detected titanium oxide species that appeared to have been exsolved from iron oxides; roughly half of the assayed titanium content in these samples has taken this form. Radiometric age dating of RC drill cuttings samples from Boulder prospect produced a range of ages, including a sample at 1598±70 Ma which correlates to emplacement of the Hiltaba Suite and Gawler Range Volcanics. Previously, age dating of gneissic outcrops at Cedric Bore prospect had returned ages of 1743±20 Ma and 1768±25 Ma. RC hole 14BUN001 was drilled to test a gravity high within the Bundi prospect. From 4 to 80 m the hole intersected tholeiitic dolerite dyke rock, with slightly anomalous copper geochemistry averaging 180 ppm Cu, intruding high grade metamorphic felsic gneisses dated at ~2450 Ma, probably derived from a sedimentary protolith. The dyke rocks, which petrographically appear to be post kinematic, date as early Hiltaba event time. RC hole 14BUN003 was drilled to test a conductor within Bundi prospect located by the 2013 trial AMT survey. It encountered felsic schists and gneisses with strong sericite alteration, but missed hitting the conductor due to the hole trajectory steepening at depth. A downhole TEM survey was carried out in October 2014 to more accurately fix the conductor's location, and then it was redrilled later on via hole 15BUNRC001. This hole intersected gneisses intruded by dolerites, and at ~129 m downhole depth intersected graphite on the margins of a dolerite intrusion, which explained the conductor. RC holes 14BL001 and 14CP001 put in at the Boulder and Claypan prospects respectively were targeting coincident magnetic and gravity highs, and both encountered parts of a similar suite of metamorphosed basic igneous rocks (probably anorthositic) having anomalous iron and titanium content, the Ti level being around twice that of a common gabbro. Because of this rock chemistry and the apparently variable differentiation seen on MgO vs SiO2 crossplots, it was surmised that the related rocks may form part of a metamorphosed layered igneous complex. Besides the metabasic rocks, both holes also encountered granodiorite and granite gneiss. RC hole 14CB003 at Cedric Bore prospect targeted a discrete small gravity high within a more extensive magnetic high anomaly, and it encountered greenschist metamorphosed anorthosite/gabbro which has been subjected to chlorite-epidote alteration, ?intruded by microgranite/micromonzonite which has been subjected to red rock alteration. The basic igneous rocks were assumed to be the source of both the gravity and the magnetic anomalies. A single sample taken from a slightly more basic layer in the anorthosite was radiometrically age dated, returning 1881 Ma from zircon and 1430 Ma from sphene. The basic igneous rocks here are thus younger than those intersected in the Boulder and Claypan prospects, and are not nearly so Fe and Ti rich. The age of their alteration was not ascertained, but it appeared to be post-kinematic and so warrants further investigation. RC/diamond hole 14NB001 at No Brainer prospect was drilled to test a discrete coincident gravity and magnetic anomaly. It encountered very high grade metamorphic rocks comprising gneisses of quartz-monzonite to monzodioritic composition, which are intercalated with more mafic to ultramafic granulite gneisses and charnockite that are intruded by amphibolite grade metamorphosed basalt dykes. Some of the cored mafic rocks contain visible pyrrhotite and pyrite, but seem to be devoid of any base metal sulphides. These mafic rocks probably account for both the gravity and magnetic anomalies. During licence Year 4, no field work was done. Apollo Minerals continued to review its drilling results from the previous year, and then decided to withdraw from its joint venture agreement with Mincor Iron Holdings, effective as of 15/4/2016. The company committed to completing all outstanding rehabilitation requirements, with site works expected to commence in late June 2016. During licence Year 5, the lease was sold by Mincor Iron Holdings to Trafford Resources on 27/03/2017. As a result of the transfer no field work was undertaken, and no new technical data were acquired.

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About this record

Record No mesac28244
Topic Geoscientific Information
Type of Resource Document
Category Type
Document Type Mineral Company Report - Mineral Exploration
Contributor Apollo Minerals Limited;Moombarriga Geoscience Pty Ltd;Southern Geoscience Consultants Pty Ltd;Search Exploration Services Pty Ltd;Daishsat Pty Ltd;Bureau Veritas Minerals Pty Ltd;A. and A. Crawford Geological Research Consultants;Zonge Engineering and Research Organisation (ZERO)
Sponsor Apollo Minerals Limited
Tenement EL 4932
Tenement Holder Mincor Iron Holdings Pty Ltd;Trafford Resources Pty Ltd
Operator Apollo Iron Ore (No. 2) Pty Ltd
Geological Province
Mine Name Eaglehawk prospect;Bundi prospect;Boulder prospect;Claypan prospect;Cedric Bore prospect;No Brainer prospect
Stratigraphy Mulgathing Complex
Commodity
Notes
Notes: This release to the public of the subject mineral exploration data, namely, company data which was acquired more than 5 years ago, is being done by DMITRE in accord with the provisions of Section 77D of the Mining Act 1971 and Regulation 88...

Notes: This release to the public of the subject mineral exploration data, namely, company data which was acquired more than 5 years ago, is being done by DMITRE in accord with the provisions of Section 77D of the Mining Act 1971 and Regulation 88 of the Mining Regulations 2011. During February 2013, grant licensee Mincor Iron Holdings Pty Ltd ('Mincor'), a wholly owned subsidiary of Mincor Resources NL, agreed to a farm-in joint venture proposal received from Apollo Minerals Limited ('Apollo'), whereby Apollo may earn a 75% interest in EL 4932 by sole funding exploration works over a 3-year period. The start of the agreed Eaglehawk JV earn-in period was deemed to be the later commencement date for the WPA Deed of Access granted to Mincor on 31/5/2013. Exploration done on the subject licence has been carried out in conjunction with related work done on contiguous tenements comprising the greater Titan Base-Precious Metals Project area. However, due to the various different participants' joint venture agreements which are in place covering those adjacent tenements, the relevant technical reporting of specific exploration progress on EL 4932 has perforce been separated into the reports described herein. It should be realised that these exploration results need to be considered in the context of the entire exploration datasets relating to ELs 4960, 5073 and 5074 (held by Southern Exploration Pty Ltd) and EL 5348 (held by Apollo Iron Ore No. 2 Pty Ltd). Geographic Locality: Commonwealth Hill Station;Comet Outstation;Woomera Prohibited Area;2014 Bundi South IP Survey;2014 Commonwealth Hill III Gravity Survey Doc No: Env 12410 Drillhole: BNSRB001;(340475);BNSRB002;(340476);BNSRB006 - BNSRB009;(340477 - 340480);BNSRB011;(340481);BNSRB013 - BNSRB023;(340482 - 340492);BNSRB030 - BNSRB032;(340493);(340494);BNSRB034 - BNSRB039;(340495 - 340500);BNSRB047 - BNSRB054;(340501 - 340508);BNSRB056 - BNSRB070;(340509 - 340523);BNSRB073 - BNSRB076;(340524 - 340527);BNSRB080 - BNSRB159;(340528 - 340607);BNSTX001 - BNSTX141;(340608 - 340748);14BUN001;(364267);14BUN003;(364274);15BUNRC001;(364275);14NL001;(364268);14NL002;(364269);14BL001;(364270);14CP001;(364271);14CB003;(364273);14NB001;(364272)

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Language English
Metadata Standard ISO 19115-3

Citations

Use constraints License
License Creative Commons Attribution 4.0
Persistent identifier https://pid.sarig.sa.gov.au/document/mesac28244
Citation Pang, D.;Clent, W.;Evans, S.;Allport, J.;Coopes, G.A.;Abbott, C.;Walkom, N.J.;Maude, G.;Kammermann, M. 1917. Data release - as updated [made at SA Director of Mines' discretion] : Commonwealth Hill area (the Eaglehawk Joint Venture Project). Annual reports for the period 22/6/2012 to 21/6/2017. Mineral Company Report - Mineral Exploration
https://pid.sarig.sa.gov.au/document/mesac28244

Technical information

Status
Maintenance and Update Frequency
Geographic Reference GDA2020 (EPSG:7844)
Geo bounding box {"type":"Polygon","coordinates":[[[134,-30.5],[135,-30.5],[135,-29.5],[134,-29.5],[134,-30.5]]]}
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