Exploring for the future: new U-Pb geochronology for the South Nicholson region and implications for stratigraphic correlations

SummaryZircon and xenotime U-Pb SHRIMP geochronology was conducted on samples from the South Nicholson Basin, and western Mount Isa Orogen. These samples were collected from outcrop and core from the Northern Territory and Queensland. The age data indicate the South Nicholson Basin was deposited after ca. 1483 Ma but deposition most likely had ceased by ca. 1266 Ma; the latter age likely represents post-diagenetic fluid flow in the area, based on U-Pb xenotime data. Geochronology presented here provides the first direct age data confirming the South Nicholson Group is broadly contemporaneous with the Roper Group of the McArthur Basin, which has identified facies with high hydrocarbon prospectivity. In addition, geochronology on the Paleoproterozoic McNamara Group provides new age constraints that have implications for the regional stratigraphy. The data obtained in this geochronological study allow for a comprehensive revision of the existing stratigraphic framework, new correlations and enhances commodity prospectivity in central northern Australia.