Data release - as updated [made at SA Director of Mines' discretion] : Curnamona JV Project area (including Benagerie and Kalkaroo). Combined annual reports for the period 10/5/2003 to 31/12/2007.
Created: 12 Nov 2024 Revised: 12 Nov 2024

Ongoing exploration carried out by project operator Havilah Resources under its newly ratified, twelve exploration licence Curnamona Project Amalgamated Expenditure Agreement, for the period 15/10/2003 to 31/12/2004, consisted mainly of drilling...

Ongoing exploration carried out by project operator Havilah Resources under its newly ratified, twelve exploration licence Curnamona Project Amalgamated Expenditure Agreement, for the period 15/10/2003 to 31/12/2004, consisted mainly of drilling done on 2 ELs, plus the acquisition of a low level, 5000 line km aeromagnetic survey over the northern part of the Benagerie Dome structure. On Benagerie EL 2812, Havilah drilled a total of 209 inclined holes on four main prospects for a total penetration of 21,459 m, the majority of these holes being aircore drilled on the Portia gold prospect, while on Kalkaroo EL 2720, after 9/11/2003, 57 combined AC/RC inclined appraisal holes were drilled along 21 traverse lines spaced 100 m apart, for a total penetration of 9938 m. In addition, considerable data compilation and evaluation work was carried out on all other ELs. This included evaluation of earlier drilling on ELs 3072 and 2740 that was completed just before the 4/12/2003 commencement date of the Project Amalgamated Expenditure Agreement. At the Kalkaroo prospect, Havilah's 2004 appraisal drilling programme confirmed its earlier computer-visualised 3D model for this mineralisation occurrence, viz. that it comprises a large, stratabound epigenetic copper-gold deposit curving around the north-plunging nose of the Kalkaroo dome. The Cu-Au-Mo mineralisation occurs in a typical Curnamona region Cu-Au horizon setting, in chemically-altered sediments along the contact between an albitite-magnetite footwall and carbonaceous pelite hangingwall. As far as is known, this geological sequence continues for tens of kilometres, and therefore there is potential for the discovery along its strike of both extensions to and repetitions of Kalkaroo - type mineralisation. Based on its 2004 drilling results at Kalkaroo and selected drilling results from earlier explorers there, namely Placer, Newcrest and MIM, Havilah undertook a detailed resource estimate and mine plan evaluation study using block models generated in VULCAN 3D software. The main conclusions that came from this study, as reported to the ASX, are - Kalkaroo contains a Measured Resource of 80 million tonnes at a copper equivalent grade of 0.9%, calculated in accordance with the JORC Code. Converted to gold equivalent terms at current metal prices, this equates to a gold deposit of approximately 5.2 million ounces at a grade of 2 g/t. - Within this Measured Resource envelope, the current open pit mine design captures 56 million tonnes of 0.48% copper, 0.47 g/t gold and 131 ppm molybdenum (applying a 0.4% copper equivalent cut-off grade to external and internal waste). This equates to a copper equivalent grade of 1.04% or a gold equivalent grade of 2.4 g/t. - This resource is sufficient to maintain a 5,000,000 tpa mining operation for a period of at least ten years at an annual production rate of approximately 25,000 tonnes copper, 79,000 ounces gold and 683,000 kg molybdenum. The second year of Curnamona Project licences' jointly reported exploration, for the period 1/1/2005 to 31/12/2005, took place on ELs 2812, 3256, 3442 and 3482. On Benagerie EL 2812, 21 combined aircore/RC holes for a total of 3,238.5 m were drilled on four prospects within the northern Benagerie Dome, i.e. North Portia, West Portia, Bassanio and Arragon. Drilling of the extensions of the North Portia Cu-Au-Mo mineralisation produced several potentially ore-grade intercepts, including 84 m @ 1.03% Cu, 0.78 g/t Au and 159 ppm Mo in hole NPRC024. These and earlier drilling results will be incorporated into a new resources estimate for the North Portia deposit in due course. Drilling along strike extensions to the south towards the Portia gold prospect clearly intersected the mineralised horizon, but with weaker mineralisation evident. Testing for possible refolded fold repetitions of the North Portia mineralised horizon at the West Portia and Arragon prospects intersected only weakly mineralised footwall rocks. Time did not permit further drilling in the vicinity to locate possible up-sequence rocks. On Eurinilla EL 3256, exploration included a low level aeromagnetic survey and computer data base compilation. Havilah considers the the Eurinilla Dome to be highly prospective, and is exploring it for Portia/Kalkaroo and Cloncurry style iron oxide - associated copper-gold (IOCG) and gold - only deposits, as well as for stratiform – stratabound Broken Hill and Mount Isa style zinc-lead-silver deposits. On Kalkaroo EL 3442, 37 AC/RC holes for a total of 6359.5 m were drilled under PACE Initiative Drilling Collaboration DPY2-55, to test for the continuation or repetition of Kalkaroo style Cu-Au-Mo mineralisation within the prospective Bimba Formation sequence. 26 of these PACE holes were drilled on 12 lines laid out around the southern Kalkaroo dome, and the other 11 holes were drilled on 9 lines distributed around the southern nose and around the eastern flank of the northern Kalkaroo dome. A further 2 AC/RC holes for a total of 374 m were drilled to test the Deep Well prospect. Significant intervals of highly anomalous to sub-economic copper and gold mineralisation (including some native copper) were intersected on drill traverses 2 to 5 on the western flank of the southern Kalkaroo dome. The best intervals include 45 m @ 0.36% Cu, 18 m @ 0.55% Cu, 87 m @ 0.30% Cu and 0.5ppm Au, 69 m @ 0.67 ppm Au, and 24 m @ 164 ppm Mo. Scattered 3 m drill cuttings sample intervals range up to 1.79 ppm Au and 1250 ppm Mo. An altered and mineralised dioritic intrusion which was intersected in one drillhole, KKRC072 on traverse 5, is of special significance as it averages 0.43 ppm Au over 36 m, with a maximum value of 3 m @ 1.54 ppm Au. The extent of the intrusion is unknown, and the strike length of untested prospective sequence to the north and south of this intersection is considerable. Significant intersections of highly anomalous Cu, Au, Mo and Zn were made on the southern nose of the southern Kalkaroo dome (on traverse 7), including 27 m @ 1794 ppm Cu, 15 m @ 240 ppm Mo, 12 m @ 3900 ppm Cu and 0.58 ppm Au, and 54 m @ 1950 ppm Zn. Some highly anomalous results obtained from drillholes on the eastern flank of the northern Kalkaroo dome confirmed the anomalous values reported from previous company drilling, with intersections including 42 m @ 876 ppm Cu, 15 m @ 242 ppm Mo, 21 m @ 462 ppm Mo, and 18 m @ 2242 ppm Zn. In other work, limited reconnaissance drilling undertaken at the Homestead, McBrides Dam, Satchell Dam and Eurinilla Dome gravity features failed to encounter any significant elevated gold or base metal values within the target rock sequence. The third year of Curnamona Project exploration activities, for the period 1/1/2006 to 31/12/ 2006, took place on ELs 3256, 3442, 3482 and 3586. On Eurinilla EL 3256, exploration included the drilling of two RC holes to test for copper-gold mineralisation that might have formed around the Eurinilla Dome within the same “prospective sequence” that hosts mineralisation around the Kalkaroo and Benagerie Domes. These holes were drilled in conjunction with five holes on Mulyungarie EL 3482, which also contains extensions of the Eurinilla Dome. The overall drilling programme was successful in providing reconnaissance information about the approximately 20 kms of strike of the prospective sequence around the Eurinilla Dome. The prospective sequence was intersected in a number of holes, and two holes also reached the magnetic albitite footwall, thereby providing good geological information on the position and dips of the main lithologies. Observed differences in lithologies between the Kalkaroo sequence and the Eurinilla sequence include the lack of bedded carbonate/calc-silicate rocks, the lower degree of albitisation, and the occurrence of massive sulphide bands/layers at Eurinilla. One hole, EURC002 on the Eurinilla tenement, intersected potentially economic mineralisation of 21 m of 0.48% Cu from 138 m depth. On Mulyungarie EL 3482, mineralisation of potentially economic significance was intersected in hole HMURC073 with 42 m of 1.44 ppm Au from 36 m depth. These results provided encouragement for further drill testing of the mineralised zones along with further drill targeting of the prospective sequences elsewhere around the dome, particularly in areas of interpreted cross cutting structures. On Kalkaroo EL 3442, the main aim of the 2006 drilling programme was to test the east-west trending quartz veined breccia zone that passes through the central Kalkaroo Dome, in the footwall of the Kalkaroo Cu-Au deposit (Kalkaroo Central prospect) and along extensions of this structure to the west (Kalkaroo West prospect). This structure was considered to be the most likely conduit for the fluids which gave rise to the stratabound vein and replacement style mineralisation of the Kalkaroo deposit, and is known to be Au-Cu mineralised where intersected by previous drilling. In addition, nine holes drilled at Deep Well were targeted to test anomalous Cu/Au results intersected by previous explorers including Newcrest and Mount Isa Mines. At Kalkaroo West, significant and potentially economic Au-Cu mineralisation is closely associated with the quartz veining but not restricted to it. Native copper and very fine specks of visible gold are common in the deeply weathered and oxidised zone within the breccia. Examples of the best intersections at Kalkaroo West include: KKRC097: - 78 m @ 0.5% Cu and 0.75 g/t Au from 75 m KKRC102: - 76 m @ 0.67% Cu & 0.63 g/t Au from 123 m KKRC127: - 81 m @ 0.48% Cu & 1.6 g/t Au from 78 m KKRC130: - 27 m @ 1.18% Cu & 2.03 g/t Au from 123 m, and KKRC125: - 39 m @ 1.18% Cu and 0.86 g/t Au from 114m. Two holes drilled to test for shallow oxide mineralisation on a line 1.3 km along the structure to the west, reported only scattered weak Au and Cu results (max 3 m @ 0.89 g/t Au & 2250 ppm Cu). At Kalkaroo Central, drilling outlined a similar but apparently more poorly mineralised quartz vein breccia over 400 m of strike. Broad intervals of low grade Cu and narrower intervals of significant Au values were reported, examples of the best being: KKRC119: - 61 m @ 0.15% Cu from 56 m KKRC120: - 15 m @ 1.68 g/t Au from 96 m, including 6 m @ 3.27 g/t Au from 105 m, and KKRC123: - 51 m @ 0.36 g/t Au. Drilling difficulties were experienced in the breccia zone at both prospects, and significant amounts of water were encountered, which should be taken into account when considering the assays. The drilling programme conducted at Kalkaroo West and Central was very successful in that it confirmed the model, delineated new, significant and potentially economic mineralisation, and greatly improved the knowledge of the local geology and controls on mineralisation. The drilling has only partially tested the breccia zones at both prospects, and further drilling along strike and downdip is required, where considerable potential remains. The Deep Well drilling intersected a package of rocks with broad similarities to but with some significant differences to the typical Kalkaroo sequence. The rocks are not strongly albitised, with only local “cherty” albitisation observed. The overall metamorphic grade appears to be higher than at Kalkaroo, with some of the pelites appearing to be hornfelsed and the Kalkaroo Unit 2 carbonates metamorphosed to calc-silicate lithologies, suggesting the presence of a nearby intrusion. The Unit 1 (footwall) magnetic albitites where intersected are generally similar to Kalkaroo in the weakly magnetic areas at Deep Well, but are significantly different in the higher intensity magnetic domains. The magnetite is coarser grained and more abundant, and the rock is more siliceous, suggesting an alteration overprint in these areas. Mineralisation observed was generally weak and was mainly restricted to the interpreted Unit 2 calc-silicates, where there were increased sulphides, mainly pyrite but with trace to minor chalcopyrite. Minor fine native copper was observed near the base of weathering in a few holes. Best intersections were: KKRC112: 9 m @ 0.47% Cu plus 7.6ppm Ag from 155 m KKRC110: 9 m @ 0.39% Cu + 0.87 ppm Au from 173 m, and KKRC104: 21 m @ 0.22% Cu + 4.6 ppm Ag + 1745 ppm Zn from 132 m. On Benagerie EL 3586, continuing exploration of the Portia deposit included the drilling of 38 aircore holes totalling 4011 m, in two campaigns. The first seventeen holes, drilled in March 2006, were oriented north-south to test possible east-west trending gold hosting quartz vein sets, which may have been missed by previous east-west drilling traverses. The remainder, drilled in September, were concentrated at the base of the proposed pit area to confirm the presence of gold mineralisation in the weathered basement below the area of previously defined best mineralisation. Results from the first drilling campaign revealed several high grade gold intersections obtained from the gold-bearing layer at the base of the Tertiary cover sequence. Results from the second drilling campaign significantly extended the gold mineralised intervals, and increased the potential tonnage of gold bearing material. Havilah is continuing to investigate the feasibility of excavating a trial open pit at Portia to obtain a large bulk sample in order to more accurately estimate the grade and distribution of gold within the deposit, since it has become apparent that the total gold resource at Portia is greatly influenced by several extremely high grade gold zones, whose dimensions are very difficult to constrain by drilling. During the fourth year of the Curnamona Project, field activities were carried out only on ELs 3442 and 3586, although considerable data compilation and evaluation work was carried out on all the other project licences. On Kalkaroo EL 3442, which includes the Kalkaroo Northern Main Dome, Kalkaroo West and Kalkaroo Central Prospect areas, evaluation of copper-gold-molybdenum resources progressed over the period June 2007-December 2007. Work included a delineation drilling program (still ongoing - where 27 holes, comprising 18 diamond drillholes and 9 RC drillholes, were completed during the period for a total of 5945.5 m), metallurgical drilling and sampling programs (via 13 dedicated holes totalling 2470.9 m, comprising 8 large diameter diamond cored holes, 4 RC drillholes and 1 abandoned rotary mud drillhole), and the assaying of 1 m samples from selected 3 m composites from the 2006 RC drilling program. The delineation drillholes were completed 40 m apart along fences spaced at nominal 100 m intervals along the strike of the deposit, closing to 50 m intervals in areas of higher grade (Kalkaroo West). The metallurgical drilling was conducted with the objective of completing the acquisition of sufficient, suitable fresh diamond drillcore (and subordinate RC drill chips) for conducting reconnaissance testwork on selected major mineralisation types from Kalkaroo West and Kalkaroo Northern Main Dome. On Benagerie EL 3586, exploration activities were confined to the drilling of 7 diamond core holes for 996.5 m at the Portia prospect, and the completion of re-bagging and re-sampling of existing drill samples at the Portia, North Portia and Shylock prospects. Also, rehabilitation of drill sites from previous years drilling campaigns was carried out at the Portia, North Portia, Shylock, Arragon and Tubal prospects. The aim of the new diamond holes was to obtain relatively large diameter (PQ3), good quality core of the cover sequence, the eluvial gold mineralisation in the base of Tertiary layer, and the primary gold mineralisation in the underlying weathered basement or saprolite. This was to provide a more detailed study of the mode of occurrence and metallurgy of the gold mineralisation, than had been possible from the previous aircore and RC drilling, and also to provide information on the geotechnical properties of the overburden and underlying host rocks, which will be required in the planning of a trial open pit mine. The holes were located within the square which would form the floor of a proposed trial pit, where the best gold mineralisation occurs. As expected, each hole reported significant gold grades from the base of the Tertiary layer, and visible gold was actually logged in this layer in holes PTDD206 and 211. Holes PTDD206 and 207 reported long intervals of significant gold grades in the weathered basement, with grades generally decreasing down hole and in the range of 1 to 3 g/t Au above the base of oxidation and 0.5 to 1.0 g/t below it. Each hole intersected the target stratigraphic units almost exactly as predicted from the interpretations based on the previous aircore and RC drilling. Core recoveries were good and the structure and fabric of the rock well preserved, even where totally weathered to clay saprolite. Three sets of relatively fine variably pyritic albite (or K feldspar?) veins occur in the pyritic albitite and graphitic pelite (GP) units, which strike north-south and dip both east and west, while another set of very fine veins strikes east-west and dips very steeply to the north or south. While some albitisation is associated with these veins, other patchy albitisation in the GP unit appears to predate them. Very minor thin weakly pyritic quartz veins occur in places. Hole PTDD212 was designed to better intersect the westerly dipping set of albite veins and although some were intersected, they were not greatly significant. None of the veining stood out as an obvious source of the gold.

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About this record

Record No mesac24669
Topic Geoscientific Information
Type of Resource Document
Category Type
Document Type Mineral Company Report - Mineral Exploration
Contributor UTS Geophysics Pty Ltd
Sponsor
Tenement
Tenement Holder Havilah Resources NL;Lynch Mining Pty Ltd;Platsearch NL;Newcrest Mining Ltd
Operator Havilah Resources NL
Geological Province
Mine Name Kalkaroo copper-gold-molybdenum deposit;North Portia prospect;Portia prospect;Shylock prospect;Tubal prospect;Kalkaroo prospect;West Portia prospect;Bassanio prospect;Arragon prospect;Deep Well prospect;Mulyungarie Homestead prospect;McBrides Dam prospect;Eurinilla Dome 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. On 8/3/2004, the SA Minister of Mines and Energy formally approved a previously agreed (in November 2003) 100% transfer of licence ownership for Kalkaroo EL 2720 from Placer Dome Asia Pacific Ltd (87.5%) and MIM Exploration Ltd (12.5%) to Havilah Resources NL. EL 2720 was renewed over the same area on 25/10/2005 as EL 3442. Geographic Locality: South-eastern Lake Frome Plains;Olary Ranges;Billeroo West;Kalkaroo;Mulyungarie;Benagerie;Emu Dam;Chocolate Dam;Lake Charles;Lake Namba;Swamp Dam;Telechie;Yalu;Eurinilla;Billeroo West;Mundi Mundi;Telechie North;Border Block;Mundaerno Hill;2005 Kalkaroo Dome, Eurinilla, McBrides Dam, Kalkaroo Saddle Aerial Magnetic Survey;2005 Kalkaroo Dome, Eurinilla, McBrides Dam, Kalkaroo Saddle Aerial Radioactivity Survey Doc No: Env 11046 Drillhole: NPAC001 - NPAC011;(261392 - 261402);NPRC012 - NPRC018;(261403 - 261409);NPAC019 - NPAC021;(261410 - 261412);PTAC001 - PTAC162;(261413 - 261574);PTRC163 - PTRC167;(261575 - 261579);SHAC001 - SHAC019;(261580 - 261598);TH1 - TH3;TUAC001 - TUAC004;(261602 - 261605);KKRC001 - KKRC141;(209623);(209624);(209745 - 209749);(214449 - 214478);(227938 - 227940);(227973 - 227975);(229021 - 229044);(261606 - 261662);NPRC022 - NPRC033;(210038 - 210049);WPRC001;(210050);BARC001 - BARC006;(210051 - 210056);ARRC001;(210057);TURC005;HMURC059 - HMURC061;(210185 - 210187);HMUAC62 - HMUAC65;(210188 - 210191);HMURC066 - HMURC074;(232739);(232746);EURC001;(232744);EURC002;(232745);PTAC168 - PTAC205;(270766 - 270803);KKDD0142;KKRM0143;KKDD0144 - KKDD0148;KKRC0149;KKDD0150;KKRC0151;KKDD0152;KKRC0153;KKDD0154;KKRC0155;KKDD0155a;KKDD156 - KKDD0159;KKRC0160 - KKRC0167;KKDD0168 - KKDD0178;KKRC0179;KKDD0180;(283742 - 283788);PTDD206 - PTDD212;(315583 - 315589) Drillhole Unit No: 6935 00323;THROUGH;6935 00342;6935 00366;6935 00579;7034 01585;7034 01718;7034 02241;7034 02297;7035 00741;7035 00749

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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/mesac24669
Citation Giles, C.W.;Just, T.L.;Price, L.A. Data release - as updated [made at SA Director of Mines' discretion] : Curnamona JV Project area (including Benagerie and Kalkaroo). Combined annual reports for the period 10/5/2003 to 31/12/2007. Mineral Company Report - Mineral Exploration
https://pid.sarig.sa.gov.au/document/mesac24669

Technical information

Status
Maintenance and Update Frequency
Geographic Reference GDA2020 (EPSG:7844)
Geo bounding box {"type":"Polygon","coordinates":[[[139.5,-32],[141,-32],[141,-31],[139.5,-31],[139.5,-32]]]}
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