This Record presents data collected in March 2022–February 2023 as part of the ongoing Northern Territory Geological Survey–Geoscience Australia SHRIMP geochronology project under the National Collaborative Framework agreement and Geoscience Australia’s Exploring for the Future Program. New U–Pb SHRIMP zircon geochronological results were derived from sedimentary rock chip samples of the Warburton Basin collected from four petroleum exploration wells (Beachcomber 1, Thomas 1, Simpson 1, Colson 1) in the southeastern corner of the Northern Territory. Geologically, this is a region in the Simpson Desert that encompasses several superimposed intracratonic sedimentary basins that are separated by regional unconformities that extend over areas of adjoining Queensland, South Australia and New South Wales. The exposed Mesozoic Eromanga Basin overlies the late Palaeozoic Pedirka Basin, which is largely restricted to the subsurface. The Warburton Basin is an early Palaeozoic pericratonic basin containing an early Cambrian and Ordovician succession (Edgoose and Munson, 2013), with possible Devonian rocks observed in some areas (Radke, 2009). As the Warburton Basin is entirely concealed beneath the Pedirka and Eromanga basins, our current understanding of the geology of the western Warburton Basin is constrained by the lack of surface exposures, the small number of well penetrations, limited biostratigraphic age control, and relatively sparse seismic data coverage.
The samples analysed herein were collected to aid in understanding the chronostratigraphy and provenance characteristics of the concealed Warburton Basin. All four sedimentary samples are dominated by Mesoproterozoic detritus (ca 1000–1300 Ma), have fewer zircons of Paleozoic age, and generally have sparse older Palaeoproterozoic–Archaean aged zircons. Samples from the two westernmost wells yielded 238U/206Pb maximum depositional ages of 469 ± 9 Ma (Colson 1) and 394 ± 6 Ma (Simpson 1). Samples from the two easternmost wells yielded older 238U/206Pb maximum depositional ages of 569 ± 10 Ma (Thomas 1) and 506 ± 5 Ma (Beachcomber 1). These data imply that known Devonian stratigraphy extends at least as far as the Simpson 1 well, but may not extend further east.
BIBLIOGRAPHIC REFERENCE: Kositcin N, Verdel C and Edgoose C, 2023. Summary of results. Joint NTGS–GA geochronology project: western Warburton Basin, March 2022–February 2023. Northern Territory Geological Survey, Record 2023-006.
