Data release - as updated : Lake Carnanto (part of the Curnamona Project). Annual reports to licence full surrender, for the period 13/1/2004 to 14/7/2014.
Published: 07 Mar 1914 Created: 12 Nov 2024 Revised: 12 Nov 2024

An area located ~140 km north-northeast of Olary has been explored for possible economic buried sedimentary uranium mineralisation hosted by Tertiary palaeochannel sands of the Callabonna Sub-basin. Previous exploration activities had partly...

An area located ~140 km north-northeast of Olary has been explored for possible economic buried sedimentary uranium mineralisation hosted by Tertiary palaeochannel sands of the Callabonna Sub-basin. Previous exploration activities had partly defined the geometry of the Lake Charles and Lake Carnanto Tertiary palaeochannels, both of which cross EL 3153. Uranium mineralisation discovered in 1980 at the nearby Oban prospect is associated with redox fronts in upstream palaeodrainage sediments of the Lake Charles paleochannel. During the first licence year, activities comprised conducting a literature review and assessment of past exploration records, followed by acquisition of a ground radiometric survey in the vicinity of Lake Charles bore, when 73 stations were read at 100 m intervals along three traverses to confirm a large but weak uranium anomaly seen in PIRSA gridded airborne survey radiometric data, that lay proximal to Oban. The anomaly could not be reproduced, so it is false and probably an artifact of data processing. Subsequent to this disappointment, AFMEX flew a 1116.35 line km regional Tempest EM survey over all of EL 3153 to assist in the search for palaeochannels. Coverage was along east-west flight lines 1 km apart, using a 110 m mean terrain clearance height. Some evidence was seen on apparent conductivity sections prepared from the resulting AEM data that could be a palaeochannel response, but the signal was muted. During licence Year 2, interpretation of the AEM data was continued, but no other work was done. Several channel-like features were discerned which might be drilled if newly commenced Native Title land access negotiations proved successful. The negotiations became ongoing into licence Year 3, and no work was possible then either. During licence Year 4, in November-December 2007, AFMEX was permitted by a ruling of the SA ERDC Court to perform ground disturbing operations on EL 3153, viz. a rotary mud drilling campaign of 96 vertical holes for a total penetration of 9790 m. Several palaeochannels were encountered in the western part of the licence area, with redox roll fronts developed within their sediments that have associated radioactivity anomalies. Despite the generally wide spacing of holes (1 to 2 km between holes and a 7 to 10 km drill traverse separation), the distribution of fluvial sands and blanket sands was satisfactorily defined by the systematic hole placement, and seemed to relate closely to historic drillhole information. However, the correlation between TEMPEST AEM features and the location of the paleochannels appeared to be poor. New drillhole evidence disclosed an important thickness of sand within the Lake Carnanto channel system in the north-west of the licence area, albeit mainly reduced in nature, but no significant radioactivity was apparent on gamma ray well logs. The more extensive Lake Charles Palaeochannel was encountered in every hole along two traverses across the south central part of the licence, and exhibited interesting redox boundary transition patterns but no appreciable uranium content (maximum 135.66 ppm U in hole LC0040 at 79 m depth). During licence Year 5, in August-September 2008, AFMEX acquired a 2680 station ground gravity survey in the southern part of EL 3153 to help with mapping palaeochannels and to estimate the depth to the underlying crystalline basement. Readings were made on a 100 m x 500 m grid of 34 lines having a SW-NE line orientation. Results of the gravity survey were used to guide the selection of drillhole sites that were intended to test portions of the Lake Charles Palaeochannel downstream of the Oban deposit. The drill transects were designed to cross-cut several interpreted channel-like TEMPEST AEM features: final proposed hole spacing was 800 m apart along lines 4 km apart. Drilling resumed in November-December 2008, when 114 vertical open rotary mud holes for 11,049.5 m were completed and geophysically logged. In areas of interest, certain holes were added towards the end of this campaign to fill gaps in the lines or in between lines, with hole spacing reduced to 400 m, and line spacing reduced to 2 km. None of the holes penetrated the crystalline basement. Three holes produced anomalous gamma ray log readings of greater than 100 ppm eU3O8 (maximum 314 ppm from below 101.2 m depth in hole LC156), from the same geological palaeo-environment as the Oban mineralisation. Notably also, a Cambrian siltstone, interpreted to belong to the Balcoracana Formation, was penetrated within one hole, LC180, located on the western side of the tenement. During licence Years 6 and 7, on renewed Lake Carnanto EL 4229, no work was done. In part this was due to the economic effects of the Global Financial Crisis on establishing JV partnerships for high risk mineral exploration. By the end of 2008, AFMEX had earned an 80% interest in the uranium and gold mineral rights attached to the subject licence. During licence Year 8, AFMEX made preparations to conduct an exploratory drilling campaign in the second half of 2012. However, the envisaged programme did not eventuate within the succeeding 26 months before a decision was made in July 2014 to fully surrender tenure.

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About this record

Record No mesac25541
Topic Geoscientific Information
Type of Resource Document
Category Type
Document Type Mineral Company Report - Mineral Exploration
Contributor Fugro Airborne Surveys Pty Ltd;Daishsat Geodetic Surveyors
Sponsor Afmeco Mining and Exploration Pty Ltd
Tenement
Tenement Holder Investigator Minerals Pty Ltd;Afmeco Mining and Exploration Pty Ltd;Areva Resources Australia Pty Ltd
Operator Afmeco Mining and Exploration Pty Ltd
Geological Province Lake Eyre Basin
Mine Name
Stratigraphy Eyre Formation
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. On 28/1/2004, Afmeco Mining and Exploration Pty Ltd (AFMEX) entered into an Option Agreement for EL 3153 with Investigator Minerals Pty Ltd (Investigator), to enable it to participate in a joint venture and by sole funding exploration, earn a minimum of 51% of the uranium and gold mineral rights. AFMEX exercised this option on 1/6/2004 and from this date became the operator of the tenement. Geographic Locality: Eastern Lake Frome Plains;Mulyungarie Station;Quinyambie Station;Lake Carnanto Palaeochannel;Lake Charles Palaeochannel;1995 SAEi BHEi 4 Aerial Magnetic Survey;1995 SAEi BHEi 4 Aerial Radioactivity Survey;1995 BHEi Area 1i Aerial Magnetic Survey;1995 BHEi Area 1i Aerial Radioactivity Survey;2004 Curnamona Project Aerial EM (TEMPEST) Survey [part];2008 Lake Carnanto Gravity Survey Doc No: Env 10520 Drillhole: LC001 - LC096;(241408);(269496 - 269592);LC097 - LC210;(254350 - 254359);(260065 - 260168)

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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/mesac25541
Citation Lorilleux, G.;Bisset, A.;Chemillac, R.;Messeiller, M.;Saliba, L.;Bruce, M.;Dubieniecki, C.;Elsner, A.;Wilson, R.;MacDonald, K. 1914. Data release - as updated : Lake Carnanto (part of the Curnamona Project). Annual reports to licence full surrender, for the period 13/1/2004 to 14/7/2014. Mineral Company Report - Mineral Exploration
https://pid.sarig.sa.gov.au/document/mesac25541

Technical information

Status
Maintenance and Update Frequency
Geographic Reference GDA2020 (EPSG:7844)
Geo bounding box {"type":"Polygon","coordinates":[[[140.5,-31.5],[141,-31.5],[141,-30.5],[140.5,-30.5],[140.5,-31.5]]]}
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Lineage