<div>New Sensitive High Resolution Ion Microprobe (SHRIMP) U–Pb geochronological results for fifteen Proterozoic and late Paleozoic samples, thirteen from the Georgetown Region and two from the adjacent Cairns Region, are presented in this Record. Eleven of the samples are from cores of basement units intersected in drillholes that penetrated overlying rocks of the Karumba (Cenozoic) and Carpentaria (Mesozoic) basins. Three of these are gneisses from the undercover extension of the Yambo Subprovince (Etheridge Province) in the northeastern part of the Georgetown Region, four are of Mesoproterozoic granites from the Forsayth Subprovince (Etheridge Province) and Croydon Province farther south, and the remaining eight are from units forming part of the Carboniferous–Permian Kennedy Igneous Association, including two from surface outcrops in the Georgetown Region and two from surface outcrops in the adjacent Cairns Region.</div><div><br></div>

The South Nicholson Basin sits between the Mount Isa Province to the east and southern McArthur Basin to the northwest. The McArthur Basin and Mount Isa Province are well studied and highly prospective for both mineral and energy resources. In contrast, the South Nicholson region is mostly undercover, little studied and consequently relatively poorly understood. A comprehensive U–Pb SHRIMP zircon and xenotime geochronology program was undertaken to better understand the stratigraphy of the South Nicholson region and its relationship to the more overtly prospective adjacent Mount Isa Province and McArthur Basin. The age data indicate South Nicholson Basin deposition commenced ca 1483 Ma, with cessation at least by ca 1266 Ma. The latter age, based on U–Pb xenotime, is currently interpreted as the timing of post-diagenetic regional fluid flow. The 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. Some rocks, mapped previously as Mesoproterozoic South Nicholson Group and comprised of proximal, immature lithofacies, have detrital spectra consistent with that of the late Paleoproterozoic McNamara Group of the western Mount Isa Province which necessitates a revision of existing regional stratigraphic relationships. The stratigraphic revisions and correlations proposed here significantly expands the extent of highly prospective late Paleoproterozoic stratigraphy across the South Nicholson region and possibly, further west beneath the Georgina Basin. The data and conclusions presented here allow for improved regional stratigraphic correlations between Proterozoic basins, improved commodity prospectivity and targeted exploration strategies across central northern Australia. Presented at the 2020 Annual Geoscience Exploration Seminar (AGES)