As part of a regional project of exploration for Mississippi Valley type (MVT) lead-zinc mineralisation emplaced in tectonically and structurally 'prepared ground' within Lower Cambrian limestones, Dampier/BHP investigated rocks of this age which outcrop with known base metal enrichment in the Mount Frome - Mount Chambers area, 45 km east of Blinman. The work entailed performing semi-detailed and detailed geological mapping at 1:20,000, 1:10,000 and 1:5000 scales, conducting prospect-scale rock chip, bulk channel and stream sediment sampling, and acquiring a 4 line, 3.2 line km IP survey, with resultant anomalies being variously followed-up by diamond drilling (6 holes totalling 1869.5 m) and RAB drilling (38 holes for 445.5 m). Extensive surface and near-surface residual MVT mineralisation was defined at the Wilnuroona, Eric and Moorowie prospects. These and several other less-mineralised areas may still warrant follow-up. Initial grab sampling of three newly discovered major unconformities that were mapped within the Wilkawillina Limestone in the north-western portion of EL 807, which have associated stratabound mineralisation (galena, cerrusite, hydrozincite, smithsonite, sphalerite, malachite, azurite and fluorite) concentrated into fracture zones, returned assays of up to 5.8% Zn and 2.3% Pb. This occurrence was named the Wilnuroona prospect. Diamond drilling (5 holes) was carried out here in November 1981, but failed to intersect significant buried mineralisation (best intercept 1 m @ 0.9% Zn in drillhole DDF4). It appears that the MVT mineralisation present originally has since been removed by later dolomitization and recent weathering and leaching. The drilling here met with problems of badly caved ground, mainly below the Faunal Assemblage 2 unconformity, with a large cavern >20 m across causing one hole, DDF2, to be aborted after the loss of a core barrel. Channel sampling at 5 m intervals across a mineralised fault breccia at Wilnuroona returned Cu to 16%, Pb to 11.4% and Zn to 32.5%, plus Ag to 43 ppm, so it is apparent that good grade residual mineralisation is very poddy and sporadic along the fracture zones. Subsequently, in Nov.-Dec. 1982, a total of 480 pulverised fresh bedrock samples were collected on two separate 2-m grids laid out over better-mineralised zones of the Wilnuroona prospect, using a jackhammer to excavate pits to 1.5-2 m depth. Average combined Pb+Zn values of 3.22% and 0.46% were revealed by statistical analysis of the assay results, indicating likely grades of stratabound mineralisation applicable to this carbonate unit. During February-March 1983 four traverses of IP dipole-dipole trial surveying were read across the Moorowie prospect, but no significant anomalies were detected beneath old workings dug on scattered surface showings of base metal mineralisation (malachite and sphalerite) within Cambrian limestone. In April 1983 BHP Minerals drilled a single inclined diamond drillhole to 345 m total depth to probe possible economically mineralised north-south shear zones mapped adjacent to the abandoned historic Moorowie mine. Only sparse low grade mineralisation was encountered, returning best core assay results of 610 ppm Cu, 1200 ppm Zn and 160 ppm Pb. After farminee Esso Exploration exited a joint venture with BHP Minerals in September 1985, a programme of grid-based infill RAB drilling (38 holes for 445.5 m) was undertaken at the Eric prospect to test Pb-Zn anomalies previously identified from BHP exploratory drilling. The Lower Cambrian carbonate units underlying the eastern part of the prospect grid yielded the highest assays, from 4.3 % to 6.7% Pb, with up to 1400 ppm Zn and 1800 ppm Cu. Proposed follow-up deep diamond drilling to locate the primary source of the lead and zinc present in the weathered bedrock section at both the Eric and Wilnuroona prospects was not commenced before a decision was made to surrender the Mount Frome tenement.