The buried Menninnie Dam zinc-lead(-silver-copper) deposit, located approximately 55 km north of Kimba on northern Eyre Peninsula, and sitting adjacent to the south-eastern margin of the Gawler Ranges, is being evaluated for its future commercial viability by Menninnie Metals Ltd (held 80% by Terramin Australia Ltd and 20% by Zinifex Australia Ltd) and new majority joint venture partner Terramin. The work is being done in conjunction with similar appraisal activities being carried out by the consortium at the Angas zinc-lead-silver deposit located near Strathalbyn on east-central Fleurieu Peninsula. On 23/6/2003, Terramin purchased the Menninnie Dam EL area joint venture rights which had previously been held by Western Metals Copper Ltd, thereby giving Terramin 100% ownership of the demonstrated and potential resources at Menninnie Dam. Then on 13/11/2003, Terramin issued a stock market share prospectus seeking to raise $5 million of new exploration funds that would also enable it to look at a number of Zn(-Pb-Ag) prospects identified near both deposits, with the intent of finding possible buried additional ore reserves to boost the overall project development viability. Part of the impetus for this move was that Terramin was committed under the JV participation conditions to spend $1 million by 31/12/2005 within the four project tenements, in order to earn the 60% majority interest formerly held by Western Metals Copper. At Menninnie Dam, the zone of significant Zn-Pb mineralisation defined by previous explorers Billiton, Aberfoyle Exploration and Acacia Gold takes in an area of 4 km x 1 km within which a resource of around 20 Mt had been estimated to occur. However, the deposit boundary lies open both at depth and laterally to the north-west and the south-east. Consequently, the deposit's actual geometry and likely ore-forming controls are at present not well understood. Lately, it has been hypothesised that the orebody is not of synsedimentary, stratiform character as originally proposed, but instead could have a hydrothermally emplaced stratabound/replacement style of genesis, where the positions of fracture plane intersections and associated volcanic fluid flows passing through the Hutchison Group marbles and calcsilicate rocks have largely determined the loci of ore emplacement. Probable volcanic feeder structures are north-west aligned, as shown by the distribution of soil geochemical anomalies, and these would be prospective for mineralised intrusive plugs/dykes containing hydrothermally altered breccias. In order to minimise the need for doing much expensive drilling to extend the known resource, it was proposed to employ modern geophysical methods to try to detect inferred small but high grade bodies of replacement-style base metal sulphide mineralisation that may have formed in the buried Mesoproterozoic volcanic cover to the stratabound older metasedimentary deposit host units. Because of the highly conductive weathered sequence that overlies the Palaeoproterozoic basement, in which saline groundwater is present with measured salinities of up to 25,000 ppm TDS, it was proposed to use MIMDAS type IP surveys and EM surveys to investigate this section. During January-February 2004, a trial combined ground magnetic and MIMDAS survey was conducted for Terramin by Euro Exploration across the known deposit outline. 69 line km of magnetic readings were taken at 5 m station intervals along grid lines spaced 100 m apart, and were used to produce separate sets of east-west and north-south aligned magnetic profiles. Three of the north-south grid lines were also surveyed using MIMDAS IP methods, to create 2500 m long IP/resistivity profiles. Subsequently, during May 2004, these same three lines were surveyed by magnetotelluric arrays using a 100 m dipole length and recording in 1600 and 100 sps EMAP mode, where a set of magnetometers is deployed orthogonally to the sensor loop. During July 2004, Terramin carried out an RC drilling campaign of 15 inclined holes with a total penetration of 2104 m, that were aimed at testing six sites within a 1.5 km x 1 km subarea of the known Menninnie Dam deposit footprint for any updip orebody extensions and possible oxide lodes. These stratabound and NW 'Corridor' structural targets were based on prior explorers' RAB drilling shows and on an EL prospectivity evaluation made for Terramin by consultant AuStrike Resources Pty Ltd in May 2004, that used the Hiltaba-age replacive hydrothermal model as an alternative to the former Proterozoic synsedimentary exploration model followed by past explorers, largely via deep (to 500 m) drilling directed only at disclosing large targets. All of Terramin's 2004 RC holes were assayed at 1 m intervals by first-pass ICP analysis to scope narrow sulphide intervals and to ensure full evaluation of the geochemical dispersion and the oxide potential of the overburden, as leads into subsequent testing of the primary target zones. Four of these drillholes encountered substantial mineralised intervals within the overburden, indicating the need for further deep drill testing of the stratabound A1, B1/C1 and B2 sulphide ore horizons. Minor gold intercepts of up to 2 g/t Au also suggested the influence of an epithermal mineralising environment like that envisaged for the newly discovered Weednanna gold deposit located 10 km to the south-southeast of Menninnie Dam. During the 2004-2005 fourth licence year of EL 2848, A PACE Initiative - subsidised collaborative drilling programme proposal was prepared for PIRSA, gained approval, and was undertaken over: - the Menninnie Dam deposit B1 cerussite target which had been identified by Terramin's drilling in 2004 (returning 8 m @ 18% Pb in hole MD-RCP14); - regional calcrete geochemical anomalies previously identified by Acacia Resources Ltd. It was proposed to drill 6 traverses of vertical aircore holes at 25 m spacing – a total of 47 holes drilled to 100 m depths – to delineate extensions of the MD cerussite zone and to investigate the potential for new such horizons between prospect grid 10000N and 10400N. Regional calcrete anomalies targeted included: MD SE, plus NWC 1 & 2 (max. 1150 ppm Zn, 550 ppm Pb, 105 ppm Cu); Watsons Dam (max. 265 ppm Zn, 700 ppm Pb, 63 ppm Cu); Ultima Dam North (max. 120 ppm Zn, 70 ppm Pb, 33 ppm Cu); NWC3 (max. 79 ppm Zn, 240 ppm Pb, 40 ppm Cu); MD North (max. 74 ppm Zn, 30 ppm Pb, 29 ppm Cu); SE Cu-Au (disconnected low order Cu, Au); MD East (max. 71 ppm Zn, 26 ppm Pb, 28 ppm Cu); and MD West (disconnected low order Cu, Zn). For testing these, a nominal traverse spacing of 400 m and drillhole interval of 50 m along the traverse was chosen, based on experience of regolith drilling in the region. During the period from 21/4/2005 to 26/7/2005, 262 aircore and RAB percussion drillholes were completed over 27 traverses, for a total penetration of 8633.5 m consisting of 6605.8 m of aircore and 2027.7 m of RAB drilling. Representative samples of drill chips and dust were collected from 1-metre depth intervals, with an assay sample then being split from the bulk collection before being composited over 4-metre depth intervals. Several holes terminated in significant mineralisation, which includes the first high grade copper sulphide hit made on the Menninnie Dam tenement, and, more importantly, all of the intercepts that were made came from previously unknown zones of mineralisation. Drillholes MDAC027 to MDAC040, MDAC248 and MDAC249, combined with numerous other anomalous Pb-Zn intersections ranging up to 2.0% Pb+Zn in the B1 target area, clearly delineated two zones of bedrock mineralisation requiring follow-up diamond drilling. This mineralisation is potentially of Broken Hill style, extends over a length of at least 400 m, and is open at both ends. Drillhole MDAC113 was sited on the south-eastern side of the Menninnie Dam prospect over a large, 3 km x 1 km Zn-Pb-Cu calcrete geochemical anomaly not previously drilled. It fortuitously encountered 1 m @ 2.95% Cu, 3.7% Pb, 0.7% Zn and 185 g/t Ag from the end-of-hole depth interval 64-65 m. This drill intercept is in a strongly chlorite-altered weathered schistose rock immediately below Gawler Range Volcanics, and as such represents a different style of mineralisation that may be associated with a porphyry or stockwork system similar to the Olympic Dam metallogenic hydrothermal model. However, rare earth element (REE) assays of bottom-hole samples in MDAC113 do not have the characteristic high-REE signature of Olympic Dam breccias. A detailed structural interpretation of existing stored drill core raised significant questions in relation to the understanding of the geological structure and distribution of mineralisation at Menninnie Dam. Although the work was restricted by the lack of reliable orientation markers in drill core, it appeared that mineralisation is located in a complex fold hinge zone(s), with the fold envelope dipping east, at least locally, rather than west as previously believed. Terramin's exploratory drilling planned to take place during 2006 was intended to focus on obtaining reliably orientated core to allow structural analysis of such. During licence Year 5 of EL 2848 [ for which no discrete annual report was submitted to PIRSA, the relevant material instead being submitted later on, in combination with reporting for the ensuing three years ], the following work took place [ its metadata is herewith provided, and the relevant raw data is hereby released in digital format ]: - During October 2005, UTS Geophysics acquired for Menninnie Metals a low level (20 m sensor elevation above the surface), high resolution airborne magnetic/radiometric survey of 2661 line km recorded across the entire licence area along east-west flight lines spaced 50 m apart, that also incorporated 300 line km of infill coverage at 25 m spacing; - During December 2005, Terramin began appraisal diamond drilling of the two high grade stratabound mineralised zones outlined by the 2004 RC drilling, with an initial 2 fully cored holes, MD33 and MD34. The former drillhole was completed to TD 681.3 m, and intersected visible Zn-Pb mineralisation within the BC1 target zone. In addition, 32 aircore and RC holes for 3138 m were drilled on and around the Mallee prospect copper target in the south of the licence during November-December 2005; - During the period January-October 2006, Terramin's delineation diamond and RC drilling of the Menninnie Dam Central ore zone was continued, to further establish knowledge about lode continuity and structural controls. 33 diamond drillholes for 14,312.8 m, and 34 RC drillholes for 4434 m, were completed. The diamond drilling programme, utilising Ezi-Mark core orientation tools, initially set out to test the possibility that at least some of the mineralisation at Menninnie Dam is stratiform and structurally remobilised. Early in 2006 it became clear that most of the mineralisation is demonstrably epigenetic, cross-cutting the host strata in zones that generally dip to the east at moderate angles (40-60 degrees). The majority of the diamond and RC holes drilled in previous phases of exploration were east-plunging, i.e. orientated sub-parallel to the mineralisation, and consequently did not effectively test the potential of the prospect. Much of this potential in the Menninnie Dam Central area remains to be properly tested with optimally oriented drill holes. From the evidence accumulated to date, the Joint Venture considers that the Menninnie Dam mineralisation is related to emplacement of Hiltaba granitic plutons such as the Wilcherry Batholith that post-date Unit 1. Emplacement of these plutons and their high level apophyses may have been responsible for the doming, tilting, alteration and sulphidic mineralisation of Unit 1 and of the basement rocks underlying it. Menninnie Dam lead-zinc mineralisation is typically epithermal in character, showing evidence of low to moderate temperature precipitation of galena, sphalerite, quartz and carbonate from hydrothermal fluids as veins, carbonate replacement, and cavity fills – including breccia cements. This mineralisation is typically gold-poor (<10 ppb Au). Similar mineralisation occurs within the basal Gawler Range Volcanics to the south of the Menninnie Dam deposit. Unit 2, hosting comparatively sulphide-poor epithermal vein systems, could be the extrusive equivalent of one or more of the Hiltaba plutons.