As part of Esso's continued exploration programme for buried Late Proterozoic stratiform uranium deposits in the Uno - Corunna area, detailed geochemical, petrological, thermoluminescence and lead isotope studies were performed on samples obtained by an ongoing programme of grid-based RAB drilling to concealed basement (143 holes on Uno, total 1932 m; 23 holes on Corunna, total 718 m). The aim was to clarify the source lithotypes, likely provenance, and history of radiation damage of potentially uraniferous minerals in the drill samples. The results of this work failed to provide any encouragement for Esso to persist with searching for economic uranium deposits in EL 637. In a switch of emphasis, the base metal potential of the Carpentarian metasediments and banded iron formations of the Middle Proterozoic Hutchison Group was next investigated, firstly by re-examining previous company exploration data addressing this theme, then through regional drill-based rock chip sampling to determine background geochemical values, and latterly through re-interpretation of the aeromagnetic data to identify possible quartz-magnetite host horizons suitable for ground magnetic surveying and drilling follow-up. Close-spaced RAB drilling undertaken north-east of Lake Gilles (287 holes, total 3887 m), plus subsequent ground checking and sample analyses of three of the most prospective such interpreted horizons, have shown that the target geophysical anomalies are caused by fresh intrusive igneous rocks including gabbro, tonalite and metabasalt, while the weathered basement otherwise exhibits scant indications of stratiform base metal mineralisation.