The continuation of copper-gold exploration across the Stuart Shelf region, as part of a newly indentured joint venture project involving Western Mining Corp. (WMC) and British Petroleum (BP), has remained based on the acquisition of detailed ground gravity and magnetic surveys designed to define basement targets for exploratory/stratigraphic percussion and diamond core drilling. Early in the report period, Geoterrex of Canada were contracted by licence operator WMC to process 22,130 line km of digital data from the company's 1979 Andamooka low-level aeromagnetic/radiometric survey, in order to interpret the locations of faults, geological boundaries and other subsurface features of interest, and to generate automated computer-based estimates of depth to magnetic basement. The final report for this project was supplied to the JV in February 1982. An experimental deep resistivity sounding survey was conducted during April 1981 at three of WMC's lately drilled prospects, using the newly available Maxi-Probe EMR-16 multifrequency equipment that is under field evaluation by Geoterrex Australia. Effective depth penetration was found to be less than 450 m, with poor resolution of resistivity interfaces from there down to 600 m depth. It was concluded that larger transmit loops, more power and larger transmitter-receiver separations would give the EMR-16 system greater flexibility and depth penetration, allowing it to be more useful for interpreting gravity anomalies on the Stuart Shelf. During the first quarter of 1981, diamond drillholes were completed at Snake Gully East (SGD2), Island Dam (IDD1), Bopeechee West (BD2) and Oak Dam (AD3). Significant primary copper mineralisation was intersected by drillholes IDD1 and SGD2. In the former, basement rocks entered below 349 m depth consist of sheared and sericite-chlorite altered felsic volcaniclastics overlying pyritic carbonaceous shales. Copper mineralisation is associated with the more strongly chloritised units, e.g. 10 m @ 0.42% Cu from 377-387 m, 17 m @ 0.39% Cu from 403-420 m, and 19 m @ 0.33% Cu from 428-447 m. At Snake Gully, a succession of granites and granite breccias intruded by basic dykes was encountered below 432 m depth, and minor chalcocite, bornite and chalcopyrite are present in the breccia sequence, yielding 4 m @ 0.27% Cu from 490-494 m. During the second quarter of 1981, diamond drillholes were completed at Saddle Hill (SHD1), Phillips Ridge East (PD3), Arcoona Structure (ASD1), Acropolis (ACD2), Bopeechee (BD1) and Willaroo Lagoon (WLD1). Significant copper mineralisation was intersected by drillhole ACD2 (22 m @ 0.4% Cu from 679-701 m depth, plus 21 m @ 0.51% Cu and 35 ppm U3O8 from 716-737 m) and by the percussion precollar to IDD4 at Island Dam (28 m @ 0.33% Cu from 282-310 m, as bornite and chalcopyrite in sheared felsic volcanic rocks, 800 m west of the intercepts made in IDD1). At BD1, which was deepened from 647 m to a new TD of 941 m, the basement comprises massive arkosic sediments with magnetite and pyrite veining and minor chalcopyrite. During the third quarter of 1981, diamond drillholes were completed at Acropolis East (ACD3), Bills Lookout East (BLD3), Island Dam (IDD2, IDD3 and IDD4), Oak Dam West (AD4), Snake Gully West (SGD4) and Snake Gully East (SGD5). Significant copper mineralisation was intersected at Acropolis East, at Oak Dam West and at Island Dam. ACD3 reached basement at 640 m depth, and down to TD 1227 m passed through granite breccia with zones of haematite and magnetite-rich matrix containing pyrite and minor chalcopyrite (best assay result 2 m @ 0.3% Cu from 660-662 m, plus 4000 ppm Zn). WMC noted that the basement succession is very similar to granite breccias drilled beneath the main ore zone at Olympic Dam. Uranium values assayed were mostly less than 50 ppm U3O8. At Island Dam, IDD2 penetrated a metasedimentary succession comprising sandstones, siltstone and iron formation, which was unmineralised. This hole was sited on a gravity ridge extending east from the magnetic anomaly on which IDD1 had been drilled early in 1981. IDD3 was drilled 800 m north of IDD1, and encountered granite gneiss between 300 and 567 m depth. IDD4, drilled 800 m west of IDD1 along the strike of the magnetic anomaly, reached basement at 268 m depth and then passed through a succession of strongly altered felsic volcanic rocks and minor siltstones to TD 619 m. Bornite encountered over the depth interval 281-291 m assayed 1.9% Cu and 30 ppm Ag, and is underlain by minor chalcopyrite. AD4 was drilled on a small gravity anomaly flanking the large Arcoona Structure anomaly. Basement was reached at 727 m depth, and down to the hole's TD of 1254 m, it comprised interbedded haematitic siltstone and haematite breccias that appeared to WMC to be very similar to lithologies in the ironstone 'core' block at Olympic Dam. These dense rocks do not contain visible copper mineralisation, but are anomalous in uranium. During this period, WMC carried out a photogrammetrically-controlled regional gravity survey at 1 km station spacing [survey identity and quantum unknown} to infill between previously gridded and detail gravity surveyed areas to the south, west and north of Olympic Dam. No significant gravity anomalies were disclosed by this work. The new data was successfully tied into the surrounding prospect grids' gravity coverage. During the fourth quarter of 1981, diamond drillholes were completed at Acropolis (ACD4, ACD5), Burden Hill South (BHD1), Burden Hill North (BHD2), Torrens (TD2), Wirrda Well South-east (WRD4) and Wirrda Well (WRD5). Minor copper mineralisation was intersected in BHD2 (0.2% Cu over the depth interval 284.6-297 m, as chalcopyrite, bornite and chalcocite in veins within a metasedimentary succession of gneisses and schists) and in TD2 (sporadic chalcopyrite grading up to 0.29% Cu over 4 m, and 0.19% Zn over 6 m, down to 858 m depth, from within a thick interval of recrystallised magnetite-quartz overlying potash feldspar - rich metasediments). Ground magnetic and gravity surveys were completed in the Todds Dam South area. Early in 1982, WMC commenced the acquisition of multifrequency induced polarisation (IP) and controlled source audio-magnetotelluric (CSAMT) ground survey measurements on the Stuart Shelf, by obtaining profiles across the Olympic Dam, Wirrda Well and Oak Dam areas. Four profiles at Wirrda Well yielded IP anomalies of resistivity or phase that were deemed worthy of drill testing. Preliminary results available from an IP traverse at Oak Dam suggested that resistivity anomalies are associated with the sulphide-bearing haematite breccias cored in AD1 and with the haematite breccias and siltstones cored in AD4. WMC intends to continue to evaluate electrical survey techniques at prospects where mineralisation is known to occur. During this first quarter of 1982, diamond drillholes were completed at Acropolis (ACD6), Horn Ridge (HRD1), Snake Gully East (SGD6) and Wirrda Well East (WRD6). All of these holes were terminated some distance into various unmineralised basement plutonic or volcanic rocks. During the second quarter of 1982, diamond drillholes were completed at Torrens (TD3), Horse Well (HWD1), Red Dam (RED1) and Todds Dam South (TOD2W2). HWD1 intersected bornite and minor chalcocite within haematite veined, brecciated felsic volcanics after reaching basement at 861 m depth (best assay 17 m @ 0.64% Cu from the depth interval 902-919 m). This hole was terminated at 1097 m after failing to penetrate any source for the targeted magnetic anomaly. TOD2W2 reached basement at 612 m depth, and was terminated at TD 786 m. Here the upper part of the basement comprises chlorite-altered granite, then passes downwards into a strongly sheared, chlorite and graphite schist zone above aluminous metasediments. A 17 m thick zone within the strongly altered rocks contains abundant magnetite and moderate radioactivity. However, the magnetic rocks are insufficient to explain the magnetic anomaly on which the hole was sited. During the third quarter of 1982, diamond drillholes were completed at Acropolis (ACD7) and Hunter Hill (HUD1). Diamond drilling (then incomplete) of WRD9 at Wirrda Well prospect, which is located about 20 km south-southeast of Olympic Dam, encountered significant intercepts of primary copper mineralisation, averaging 0.8% Cu over 215 m in drill core cut below 419 m depth and containing 2-3 m lenses grading up to 3.6 % Cu and 36 ppm Ag, associated with haematite veining developed in altered granite over the depth interval 391-631 m. Chalcocite was intersected over a 70 m thick above 500 m depth, and minor bornite and chalcopyrite below this depth. In consequence of this discovery, WMC considered that Wirrda Well could represent the best prospect on the Stuart Shelf licence, as it contains large coincident gravity and magnetic anomalies, and recent ground electrical surveys performed there had indicated the existence of a broad, low resistivity polarisable layer extending in a south-eastwards direction from the gravity anomaly centre. In a press release made on 12/10/1982, the company gave details of the mineralised drill intercepts made at the prospect to date, and said that from the nine drillholes so far put in there, it is known that the mineralisation style has some similarities to that seen at Olympic Dam, although it does not contain recoverable uranium or gold. The overlying cover sequence varies in thickness from 355 m to 436 m. During this reporting period WMC continued with its programme of experimental electrical surveying, by acquiring CSAMT coverage at Wirrda Well, Torrens, Island Dam and Winjabbie prospects, and by beginning to acquire complex resistivity (CR) ground surveys, run initially at Acropolis and at Island Dam using a 600 m dipole-dipole separation. In addition, 1 km x 1 km spaced regional gravity surveying was commenced to investigate the shallow basement area located between the Andamooka Opalfield and the Island Dam prospect grid. During the fourth quarter of 1982, additional diamond drillholes were completed at Wirrda Well (WRD9, WRD9W1, WRD10 and WRD11) to investigate resistivity anomalies detected within altered granite. At WRD9, where the drillhole had to be wedged off at 667 m depth because of drilling problems, low grade copper mineralised intercepts were made over a broad interval below that depth, with scattered higher grade zones including 5.35 m @ 2.98% Cu, 12 ppm Ag and 150 ppm U3O8 from 668-673.35 m, and 15 m @ 1.75% Cu, 14 ppm Ag and 260 ppm U3O8 from 692-707 m. The mineralisation occurs within haematite-magnetite veins and irregular matrix stringers within chlorite and sericite-altered granite and granite breccia. Only minor low grade copper intercepts were made in WRD10 and WRD11, in similarly moderately altered granite having minor haematite veining. Other drillholes completed in the quarter were put in at Acropolis (ACD9) and Murdie prospects (MRD1). The latter hole, located on Lake Torrens, was completed at TD 918 m after penetrating at 806 m a basement consisting of massive to weakly banded volcanic beds (possible tuffs). Intense magnetite veining and alteration logged over the depth interval 833-884 m was thought to contribute to the magnetic anomaly on which this hole was sited. No significant mineralisation was encountered. WMC commenced downhole wireline geophysical logging of its still accessible deep exploratory drillholes during this period, running electrical logs in holes WRD9, WRD10, WRD11, ACD8 and ACD9. The three lines of CR survey data recently obtained from Acropolis yielded no anomalies of interest, and common instances of electromagnetic coupling caused doubtful interpretation results for both resistivity and AMT spectra. However, it was believed by WMC that the less ambiguous resistivity anomalies that had been detected at other nearby prospects such as Island Dam and Oak Dam might in part reflect real variations in the conductivity of the cover sequence, as well as the effects of thickness changes of units within the Pandurra Formation. On the JV's newly granted EL 993 covering the Andamooka Opalfield, 55 line km of ground magnetic profiles and 21 line km of gravity traverses were acquired at the end of 1982.