Exploration was undertaken by BHP along the western margin of the Murray Basin, between Lake Alexandrina and Cambrai township, for possible economic heavy mineral sands and for exhalative sedex-style volcanogenic/stratabound base metal deposits, both of these being commodities that hitherto had been unsought in this particular area. Following the conduct of an initial magnetic interpretation of existing airborne survey data, the HMS work comprised aircore traverse drilling and sediment sampling (110 holes, total 2013 m, along 13 traverses with holes spaced ~1 km apart) to test the Pliocene marginal marine Loxton-Parilla Sand sequence, and the resampling of archived previous company drillholes which had penetrated this unit, to obtain 30 composite heavy mineral concentrate samples for mineralogical examination. Up to 14% rutile and 38% leucoxene were observed in the separated HM concentrates of the drill cuttings grab samples taken from the SADME Core Library; however, the total HM grades were generally low ( 1% HM (maximum 2.38% HM). In conclusion, therefore, BHP considered the local heavy mineral prospectivity of the Tertiary Loxton/Parilla and younger sands as being substantially downgraded. For its base metal search, BHP initially investigated previously recognised linear regional aeromagnetic anomalies sourced within the Cambrian Kanmantoo Group metasediments, which were known to be in part prospective pyrrhotite-pyrite rich metasiltstone and black shale strata. The most promising area in the licence was thought to be the Harriet Hill fold zone on the western limb of the Monarto Syncline, where the Tapanappa Formation subcrops close to a major north-northwest trending fault coming from the Brukunga/Kanmantoo locality. After the licensee carried out reprocessing and magnetic modelling of earlier aeromagnetic data, 30 line km of ground magnetics were acquired over selected anomalies, prior to the drilling of 8 RC percussion holes for a total penetration of 1294 m. The last hole, KR92008, which was also drilled close to a CRA Sirotem anomaly, intersected a number of sulphide-rich horizons having minor (up to 20%) fine to coarse-grained pyrrhotite-pyrite-sphalerite-galena-chalcopyrite mineralisation within sericite-muscovite altered psammite and schist. Here the best drillhole intercepts were 2 m @ 1040 ppm Pb, 830 ppm Zn and 4 ppm Ag from 58-60 m depth, and 12 m @ 1797 ppm Pb, 1790 ppm Zn and 5.3 ppm Ag from 78-90 m depth, the latter interval including 4 m @ 4370 ppm Pb, 2440 ppm Zn and 12.5 ppm Ag from 78-82 m depth. As follow-up to this work, BHP undertook limited Sirotem surveying, plus 49 line km of combined gravity and ground magnetic surveys, along grids of 200 m spaced lines laid out over four prominent narrow aeromagnetic anomalies. These targets were in the vicinity of their 1992 drillholes and those drilled earlier by CRA which had revealed the syngenetic base metal sulphide mineralisation. In March 1993 eight more RC holes for a total of 1255 m were drilled by BHP to test several coincident gravity/magnetic/EM geophysical anomalies. Six of these drillholes again encountered stratabound base metal mineralisation of a similar tenor to that seen previously (e.g. 6 m @ 1283 ppm Pb, 4117 ppm Zn and 2.5 ppm Ag in hole KR93004 over the depth interval 126-132 m). However, no lithologic or mineralised sources for the relative gravity highs could be found in the target areas, which were located adjacent to prominent linear magnetic features. Only one drillhole, KR93003, may lie on a gravity high caused by an uplifted block of shallow basement, according to the results of post-drilling EM depth sounding and gravity modelling work. During June 1993, downhole EM logging was performed in the six BHP drillholes which had encountered sulphidic metasediments, and in three holes (KR93003, KR93004 and KR93006) thin but moderate to strong off-hole conductors were indicated, which were recommended for drill testing. In addition, drilling was proposed for a number of magnetic highs in the vicinity of known mineralisation that also remained untested. However, BHP management then decided that the company no longer wished to continue sole-funding the exploration of EL 1733, and after making an unsuccessful appeal for joint venture assistance, the company allowed its tenure to lapse at licence expiry in January 1994.