Data release - as updated [made at SA Director of Mines' discretion] : Nullarbor, Yalata North and Yalata East (the Western Gawler Craton Project). Joint annual reports for the period 24/10/2012 to 2/4/2018.
Created: 12 Nov 2024 Revised: 12 Nov 2024

A cluster of adjoining licence sub-blocks taken up in the Yalata region are being explored for possible buried Thompson Belt style magmatic copper-nickel mineralisation which could be associated with large strike-slip fault structures transecting...

A cluster of adjoining licence sub-blocks taken up in the Yalata region are being explored for possible buried Thompson Belt style magmatic copper-nickel mineralisation which could be associated with large strike-slip fault structures transecting the south-western corner of the Gawler Craton. During the first year of the project (13-14), a desktop geophysical review of the tenements was undertaken by Monax Mining (Monax) and an introductory meeting was held with the Aboriginal Lands Trust. A partial relinquishment of 189 square km or ~33% of EL 5077 was made, effective as of 12/12/2013. During project Year 2 (14-15), for all of the subject licences, Western Areas Ltd (WSA) entered into a joint venture earn-in agreement with grant licensee Monax on 1/10/2014, whereby it can earn a participating interest of up to 90% in two stages by sole funding an A$1.2 million exploration programme over four years. A 25,605 line km high resolution airborne magnetic survey was acquired during November 2014-January 2015 to greatly improve magnetic coverage of the project area, and its final processed data were delivered in February 2015. Interpretation of these data was commenced, following their integration with the historical regional magnetic dataset. The main survey was flown along north-west/south-east lines 100 apart using a sensor mean terrain clearance of 40 m. North-east/south-west tie lines were flown 1 km apart. Two small trial infill airborne magnetic surveys were later flown at a 50 m line spacing, using the same platform and data acquisition specifications, but they showed no appreciable increase in resolution of shallowly buried features under cover. During project Year 3, WSA began a regional scale geophysical targeting and geochemical reconnaissance drilling programme. Negotiation and consultation with the Aboriginal Lands Trust continued for obtaining permission to access the Yalata Aboriginal Lands for on-ground exploration activities. Ongoing magnetic data interpretation had revealed numerous features that may represent mafic/ultramafic intrusions, many of which are clustered in potential ‘camps’. These features were ranked and prioritised for drilling, and a successful submission was made to DSD for the grant of subsidy funding under the PACE Initiative Discovery Drilling programme. A programme of exploratory drilling was started in July 2015, and was still in progress at the end of the reporting year. Over six months, 106 vertical aircore holes with a combined penetration of 9193 m were drilled to test magnetic, conductivity and gravity anomalies. In addition, one fully cored diamond hole was drilled to TD 582.6 m at the Atomic Cafe prospect on EL 5077. A number of areas were identified as being prospective through containing widely distributed olivine gabbro-norite and hornblende pyroxenite/hornblendite intrusive igneous rocks (mafic cumulates). Importantly, many drillhole sample petrological examinations confirmed the presence of magmatic nickel/copper and copper sulphides within these rock types. Olivine gabbro-norites, in particular, are well known for hosting significant nickel and copper orebodies in Western and Central Australia, including Nova and Nebo-Babel, and their presence confirmed the industry's initial observations regarding the prospectivity of the Fowler Domain for intrusive - related nickel and copper mineralisation. Following the receipt of early drillhole identifications of prospective lithology and mineralisation, a number of test ground geophysical surveys were planned over specific areas to test the effectiveness of conventional EM and gravity data collection systems in imaging the basement through the thick Nullarbor Plain cover sequence. Trial EM coverage was made in four areas having variable thicknesses of cover and differing interpreted basement lithologies, using both moving loop and fixed loop acquisition methods to profile a total of 28 square km. Although the cover sequence proved to be variably conductive, the MLEM and FLEM data indicated that the surveys would be capable of detecting high grade (massive sulphide type) nickel or copper mineralisation lying below the cover. However, no anomalies that might represent massive nickel sulphide mineralisation were detected. Trial gravity surveys were run over grids located in the vicinity of the ground EM profiles, using a 500 m x 250 m station spacing, for a total coverage of 184 square km. The surveyed mafic intrusions showed a clear density contrast with the predominantly felsic basement rocks. During project Year 4 (16-17), WSA attained a 90% interest in the JV tenements in early 2016 and on 29th March 2016 signed the West Gawler Joint Venture Buyout Agreement with Monax. This agreement allowed WSA to purchase the remaining 10% interest in EL 5077, EL 5199 and EL 5200 and become the sole registered holder of the tenements. The regional-scale reconnaissance exploration program begun in the previous reporting period was continued, with drilling commencing in July and was completed in August 2016. A total of 31 aircore for 2446 m were drilled (WGAC0115 – WGAC0142A, WGAC0143 – WGAC0144), with drilling designed to test specific magnetic features that may represent prospective mafic-ultramafic intrusions, and to gather more broad spaced lithological information throughout the tenure, with this phase of drilling was designed to follow up specific target areas identified during the 2015-2016 drilling campaigns. Following the completion of test geophysical surveys in the previous reporting period, a ground gravity survey was carried out over all 3 of the subject licences on a nominal 500 m x 250 m station spacing, with 2 surveys completed for a total of 9522 stations covering an area of 1037.9 square km. A series of detailed Moving Loop Transient EM (MLTEM) surveys were started in November 2016 and were on-going at the end of the reporting period. The surveys were carried out over the Citadel and Sector 26 areas on EL 5200 as well as orientation slingram configuration along a 2.5 km northwest-southeast orientation re-survey line in the north of EL 5077. A comparison between the slingram and inloop MLTEM configurations determined that the slingram configuration is the best approach to filter/differentiate bedrock conductors, which has been used for the Citadel surveys during the reporting period. During Year 5 (2017-18) of the project, the regional scale geophysical targeting and geochemical reconnaissance drilling program was continued. Forty-four lines of Moving Loop EM (MLEM) was completed over 10 areas of interest, with a total of 101 line-km of data collected. The surveys were undertaken by High Power EM with 300-400 m line spacing with 100 m station spacing, utilising a slingram configuration. The reconnaissance aircore drilling (AC) drilling program was designed to test magnetic targets for potential mafic-ultramafic intrusions, as well as to gather further lithological information across the project area. A total of 52 holes for 3647.4 m was completed at the Bullet Farm, Citadel, Thunderdome and EL 5200 Pastoral prospects. The AC drilling program has been shown to be an effective for testing geophysical and geochemical targets under the Nullarbor cover sequence. Given the positive results to date, work is set to continue. Ongoing work planning and target assessment continued to define areas of future work projects.

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About this record

Record No mesac29026
Topic Geoscientific Information
Type of Resource Document
Category Type
Document Type Mineral Company Report - Mineral Exploration
Contributor Magspec Airborne Surveys Pty Ltd;Newexco Services Pty Ltd;REFLEX Geochemistry
Sponsor Western Areas Ltd
Tenement
Tenement Holder Monax Alliance Pty Ltd;Monax Mining Limited;Western Areas Ltd
Operator Monax Mining Limited;Western Areas Ltd
Geological Province Gawler Craton
Mine Name Phantom prospect;Citadel prospect;Crack in the Earth prospect;Morrowland prospect;Atomic Cafe prospect;Thunderdome prospect;Sector 26 prospect;Bullet Farm Prospect;EL 5200 Pastoral prospect
Stratigraphy
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. Includes: - Sugden, S.P., March 2016. Review of western Gawler (project area) aircore drilling results [re. epithermal gold distribution and IOCG prospectivity], plus multivariate analysis of drillhole geochemical data. Appx 2 of project third annual report to 2/4/2016. 141 pages, 2 appx, figures, 1 ref, tables. - Amann, W., 18/11/2015. Memorandum re. interpretation of Phantom prospect MLEM survey data (Newexco geophysical consultant's report for Western Areas). Appx 3 of project third annual report to 2/4/2016. 12 pages, 10 fig. Geographic Locality: South-western South Australia;Nullarbor Plain;Yalata Aboriginal Reserve;Nundroo;Yellabinna Regional Reserve;Colona Fault Zone;Coorabie Fault Zone;Tallacootra Shear Zone;Yerda Shear Zone;2014 WSA Oyster Aerial Magnetic Survey;2014 WSA Oyster Aerial DEM Survey;2015 Western Gawler Project MLEM/FLEM Survey;2015 Western Gawler Project Gravity Survey;2016 Western Gawler Ground Gravity Survey;2016 Western Gawler Moving Loop Transient EM (MLTEM);2016 Western Gawler Orientation Slingram survey line;2018 Western Gawler Craton MLEM Survey Doc No: Env 12744 Drillhole: WGAC0001 - WGAC0012a;(364293 - 364305);WGAC0013 - WGAC0036a;(364306 - 364330);WGAC0037 - WGAC0073;(364331 - 364367);WGAC0077 - WGAC0093;(364371 - 364387);WGAC0099 - WGAC0107;(364393 - 364401);WGAC0111 - WGAC0114;(364405 - 364408);WGDD0001;(364409);WGAC0115 - WGAC0142A;WGAC0143 - WGAC0144

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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/mesac29026
Citation Grant, C.D.;Dreverman, P.;Spencer, P.;O'Neill, D.;Amann, W.;Sugden, S.P.;Gregory, I.;Lockheed, A. Data release - as updated [made at SA Director of Mines' discretion] : Nullarbor, Yalata North and Yalata East (the Western Gawler Craton Project). Joint annual reports for the period 24/10/2012 to 2/4/2018. Mineral Company Report - Mineral Exploration
https://pid.sarig.sa.gov.au/document/mesac29026

Technical information

Status
Maintenance and Update Frequency
Geographic Reference GDA2020 (EPSG:7844)
Geo bounding box {"type":"Polygon","coordinates":[[[131.5,-32],[132.5,-32],[132.5,-31],[131.5,-31],[131.5,-32]]]}
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