Economic Olympic Dam style iron oxide - associated copper-gold (IOCG) mineralisation has been the target of exploration carried out in three adjoining areas which together extend for about 55 to 170 km north of Port Augusta, covering southern Lake Torrens and a 20 km wide strip of the alluvial plains and plateaux adjacent to its western side. Early in 1996, as part of his research into coincident magnetic and gravity anomalies located on Lake Torrens off Wilga Point, which had been identified in 1975 by Western Mining Corp., EL 2149 licence principal Rudy (Rodolfo) Gomez made a revised source depth estimate of 400-600 m below surface for these anomalies, which was based on his interpretation of the new aeromagnetic survey data acquired in 1995 by his private company RMG Services in partnership with the SA Government, as part of PIRSA's South Australian Exploration Initiative (SAEI Area B17). However, no exploration access onto the lake appeared feasible in the immediate future owing to the legal hindrance caused by unresolved Native Title claims applying there. The licensee switched his attention to the onshore tenement area of EL 2150, and delineated two medium-size magnetic anomalies, Beda 1 and Beda 2, which he considered worth drilling, and to fund this work he was able to attract a joint venture partner, General Gold Resources. Unfortunately, over a considerable ensuing time period, complications with all stakeholder groups being unable to settle Native Title claims held up progress in gaining on-ground access here also, and the joint venture was ultimately dissolved. During this stalemate the licensee paid for an archaeological and ethnographical study to be made of the disputed land within the subject licences. In the interim, all of the available regional aeromagnetic data for these three areas were re-processed and re-interpreted by the licensee's geophysical consultant Chris Anderson and Associates, resulting in the definition of several anomalous features near Salt Creek on EL 2150 which were then investigated by conducting an infill detailed ground gravity survey during November-December 1996, funded by General Gold Resources (204 stations read on a 500 m x 500 m spacing). After interpreting the detailed gravity data, Chris Anderson prepared a proposal early in 1997 to drill the GM1 gravity high and coincident residual magnetic feature, which lies 6 km north-east of the Elizabeth Creek Fault and 7 km east-southeast of Carpentaria Exploration's previously drilled and sub-economically copper mineralised diamond hole SASC4 on the Salt Creek prospect. No work took place on the subject licences during the 3-year period 1997-1999, while the licensee waited for the outcome of the Commonwealth Government's Wik native title legislation amendment proceedings. Regretably, when the legal drafting was finished and the Mabo Act amendments passed, their wording did not offer a definitive solution to RMG Services' land access impasse. During this waiting period, the licensee also enaged in direct dialogue with native title claimants, some of whom were supportive in writing of allowing mineral exploration to occur on Lake Torrens, which development led RMG and the other claimants to place an application before the Federal Court late in 2000 for making a judicial determination. Late in 2000, the licensee shifted his focus from the Wilga Point anomaly on EL 2149 as the primary target that merited drilling first, onto two gravity anomalies within EL 2150 on the southern onshore margin of Lake Torrens. Although small, these anomalies were thought to possibly reflect shallowly buried base metal mineralisation similar to the rich copper-cobalt deposits of Mount Gunson. By the following year, the anomaly lying closest to the southern shore of Carrapateena Arm had been given priority for drilling, a Declaration of Environmental Factors had been submitted for approval by PIRSA, and a drill site had been prepared there. However, lack of Native Title landowner permission for conducting ground-disturbing activities precluded further progress with the drilling programme. When MIM farmed into the licences in October 2002, its activity was focussed on a residual gravity anomaly of 2.5 mGal amplitude on EL 2879 that it called the “Carra-east” prospect. This gravity anomaly, which lies about 100 km south-east of the Olympic Dam deposit, is located on the edge of a deeper magnetic source, possibly a Hiltaba Suite felsic intrusion at depth, and is coincident with NW trending structural features mapped in the regional magnetics. Following the completion of a heritage clearance survey conducted with representatives of the Kokatha and Barngarla peoples who claimed to traditionally own the country, some infill gravity data was collected over this prospect to better define the gravity anomaly (207 stations were read by MIM during February-March 2003). 3D inversion modelling of the gravity data indicated an anomaly source depth of around 500 m, which roughly correlated with known depths to basement derived from the SASC2 and SASC4 drillholes. IP and MT electrical survey techniques were subsequently applied to the prospect using MIM’s proprietary MIMDAS system, to try to determine whether the gravity source of interest was also conductive and/or chargeable, indicating the presence of sulphides. Six 5 km long north-south lines spaced 400 m apart were MIMDAS profiled between March and May 2003. The results of this work identified a number of low amplitude chargeability anomalies inferred to be sourced from within the cover sequence, and not from below the basement unconformity. The resistivity models indicated that the gravity anomaly is probably due to a shallowing of basement. Some decreased basement resistivities were noted at the northern end of lines 738100E to 738900E, in both resistivity and MT data. This area, however, did not coincide with the targeted gravity anomaly. In view of the disappointing electrical survey results, which were deemed to have failed to provide strong evidence for the existence of IOCG mineralisation associated with the Carra-east gravity anomaly, MIM elected in mid-July 2003 to leave the joint venture after 9 months participation that included 3 months when force majeure was declared while the company sought permission for land access. During May 2004 consultant geophysicist Chris Anderson selected for RMG Services two optimum drilling sites at the Carra-east gravity anomaly on EL 2879, after he had evaluated all available data including the results of MIM's MIMDAS electrical survey, and could see marked similarities with the geophysical signature of the Olympic Dam deposit. Impressed by his argument for the prospect's potential, Rudy Gomez applied to the South Australian government for a PACE Initiative Theme 2 drilling cost subsidy to help with construction of both proposed drillholes, and in May 2005 he was granted this help (see related Env 11036 re. the execution of approved PACE Drilling Project DPY2-02). PACE-subsidised hole CAR2 was to be drilled to test the basement under the Carra-east coincident gravity-magnetic anomaly, while the other PACE-subsidised hole CAR1 was to be drilled to test the nearby basement wherein lay a low resistivity anomaly detected by the MIMDAS survey. Both holes were programmed to reach target depths of 600 m. During early May 2005, vertical hole CAR1 was RC precollared to 299 m depth and then was NQ diamond cored to a total depth of 570 m. Haematite-altered granitic basement was encountered beneath the Stuart Shelf metasedimentary layers, but it contained no sulphide mineralisation. Following the completion of CAR1, vertical hole CAR2 was RC precollared to 240 m depth and then was diamond cored during June-July 2005 to an interim TD of 654.2 m, this being the maximum depth capacity of the diamond drilling machine used by RMG Services. A major mineral discovery was made in this drillhole when copper sulphides and gold were found within the basement rocks, extending continuously within the interval from about 473 m to the bottom of the hole. The first 67 m of mineralised drill core, when sampled, assayed 3.03% Cu and about 0.4 grams per tonne Au. Copper sulphide mineralisation was visible in most of the drill core. Assayed drill core samples for the entire 178.2 m long mineralised depth interval averaged 1.83% Cu and 0.64 grams per tonne Au. Rare earth elements are present in significant amounts, but the uranium content is negligible. After receiving offers from many companies interested in exploring and developing the copper-gold orebody newly discovered at Carra-east prospect, RMG Services on 30/9/2005 and acting with the concurrence of PIRSA selected the Australian subsidiary of major Canadian base metal miner Teck Cominco as its joint venture partner to progress work towards establishing a mine there. In short order, as part of its commitment to realising $16 million of expenditure on the JV by the end of 2008 to thereby earn a 34% interest in the licences and thereafter to have the right to acquire them from RMG Services in their entirety, Teck Cominco assembled a team of geophysicists and project geologist to start this work. Negotiations were conducted with native title claimant groups the Kokatha, Barngarla, and Kuyani for obtaining a land access agreement to allow an engineering site survey of the prospect area. A detailed aeromagnetic/radiometric survey was acquired over the three JV project ELS during December 2005 for Teck Cominco by contractor Fugro Airborne Surveys, entailing coverage totalling 5020 line km flown along east-west lines spaced 200 m apart, with a 50 m mean terrain clearance. On-ground activity undertaken by Teck Cominco Australia during 2006 mainly consisted of RC, rotary mud and diamond drilling aimed at determining the extremities of the orebody host hydrothermal breccia system, now named the Carrapateena Breccia Complex (CBC). As part of an envisaged overall 75,000 m of prospect appraisal drilling at 200 m x 200 m hole spacing, a total of 51 holes were completed for 45,574 m, including the downward extension of RMG's CAR2 discovery hole to a new TD of 984.3 m in September-October 2006. To further investigate both Carra-east and another seven regional geophysical targets, IP, detailed ground gravity and MT surveys were conducted during late 2005 and early 2006. 2329 gravity stations were read across five different areas along 171 traverses, at either 200 m x 200 m or 400 m x 400 m station spacings. A second MIMDAS survey was run at Carra-east prospect on three overlapping grids covering 12 square km with line spacings of 400 m and receiver pole-dipole spacing of 200 m, to enable ghost 3D modelling of the resultant 2D resistivity, IP and MT data. Inversion models of the data were affected to a great degree by residual electromagnetic coupling, but by combining two complementary3D IP models, two main zones of basement chargeability were recognisable, which appeared displaced from a central conductive zone. This new geophysical information was used to help guide the sequence of holes in the appraisal drilling programme. Three main mineralised trends were identified within the host CBC by this drilling programme: an east-west trend on the southern margin of the prospect, a north-south trend on the western margin, and a central north-south trend. The best mineralised intercepts were made in the south-western part of the prospect, where assays of diamond core samples from drillhole CAR32 returned 836 m @ 0.86% Cu and 0.54 g/t Au from below 527 m depth (including 303 m @ 1.02% Cu and 0.61 g/t Au from the top section below 527 m). The width of the mineralised zone encountered in hole CAR32 exceeds 1000 m. In addition, hole CAR31 (sited 200 m north of CAR32) returned a rich intercept of 261 m @ 1.32@ Cu and 0.72 g/t Au from below 564 m depth (including 50 m @ 2.28% Cu and 0.47 g/t Au from below 722 m). The CAR2 discovery hole, including Teck Cominco's 2006-drilled extension, returned 355 m @ 1.25% Cu and 0.51 g/t Au from below 476 m depth (including 166 m @ 1.92% Cu and 0.68 g/t Au from 476 m). Within the drill core recovered from this to date more studied hole, the copper sulphide mineral assemblage composition can be separated into three distinct groups, namely, a dominantly bornite zone (476–531 m) occurring within a haematite breccia, a bornite/chalcopyrite zone (531– 599 m) occurring within a granite/haematite breccia, and a chalcopyrite zone (plus minor bornite) occurring within a dominantly polymictic haematite/granite breccia which persists to the end of the hole (599–984.3 m). Mineralisation also occurs within numerous haematite - altered and fractured mafic dykes. Intriguingly, drill cores recovered from a number of appraisal drillholes completed during 2006 showed that many haematite breccias within the CBC are devoid of any sulphide mineralisation. These barren breccias are often associated with an increased occurrence of dykes, altered dykes, brecciated dykes, carbonate, specular haematite and minor siliceous material. Exploration done on the Carrapateena JV project licences during 2007 consisted mainly of RC, rotary mud and diamond drilling to determine the lateral and vertical dimensions of bornite and chalcopyrite dominated ore zones in the CBC. A total of 50 holes for 44,330.1 m were drilled, including 7 inclined extensions to vertical holes drilled into the CBC in 2006, plus 14 vertical holes sited elsewhere to test the IOCG potential of other geophysical prospects. Some of the Carrapateena orebody delineation drilling was done at 100 m x 100 m centres to infill the regular 200 m x 200 m pattern hole sequence stepping out from the discovery hole CAR2. In addition, numerous ground surface (gravity, EM, IP and MT) and downhole (IP) geophysical surveys were conducted at Carrapateena and the other prospects. The 2007 drilling results from Carrapateena reinforced the earlier observation that particular breccia types found there have favoured the sites of formation of the two different copper sulphide mineral species, namely bornite and chalcopyrite. Bornite mineralisation is often associated with an earthy haematite/granite rich breccia, and its degree of development mostly does not seem to be affected by the percentage of granite clasts. Chalcopyrite mineralisation is associated with a variety of breccia types, with the strongest mineralisation found in breccias hosted by specular, steely and grey haematite (both clast and matrix components). The interface between bornite and chalcopyrite mineralisation is often sharp, however the lateral and vertical extents of the sulphide specie boundaries are poorly constrained and may represent several discrete zones of bornite mineralisation. Bornite zones occur at depth, beyond substantial chalcopyrite mineralisation and barren granite zones. Currently, there is no evidence for interconnectivity between deep bornite zones and bornite mineralisation in the upper section of the orebody. Ongoing petrographic studies of the CBC have shown extensive chloritisation paired with an imprint of gneissic foliation to the granite host rock, predating brecciation. These chloritised granites usually occur in association with grey haematite-rich breccias. It is possible that these chloritised granite/gneisses represent a deeper part of the granite body that has preserved ductile, low grade, hydrothermal metamorphism predating or contemporaneous to brecciation. During May-June 2007 a gravity survey was acquired over seven selected regional targets. 1040 stations were read at station spacings of 200 m, 250 m and 500 m. Following Teck Cominco's interpretation of the new gravity data, the JV proceeded to conduct exploratory vertical diamond drilling of certain prospects on ELs 3481 and 3688 during the latter half of 2007. In 12 of the completed drillholes from this programme, variably haematised, chloritised and sericitised Donington Suite granites constitute the majority of the basement rocks penetrated, sometimes having minor brecciation and specular haematite veining, and being cut in their upper parts by minor mafic and aplite dykes. Traces of copper sulphide (chalcopyrite) mineralisation were rarely visible in some of the drill cores, but the majority of granite lithologies intersected were barren. The only notable occurrence of copper mineralisation was found at the Fremantle Doctor prospect, located ~3 km north-east of Carrapateena, in hole FD1 (total depth 1070.9 m). This hole penetrated a strongly chlorite-altered granite having increasing brecciation and attendant haematite alteration going deeper in the hole, where some massive breccia sections in the drill core contain patchy minor (to 0.5%) visible sulphide mineralisation (chalcopyrite and pyrite). Core assays returned 387 m @ 0.37% Cu and 0.18 g/t Au.