The late Palaeozoic to Triassic Pedirka Basin lies in the southeast corner of the Northern Territory and is the middle of three stacked basins separated by regional unconformities extending over areas of adjoining Queensland, South Australia and New South Wales. It is overlain by the exposed Mesozoic Eromanga Basin and in turn is overlain by the Palaeozoic pericratonic Warburton Basin (Munson and Ahmad 2013). As the Pedirka Basin is almost entirely concealed beneath the Eromanga Basin, the current understanding of the geology in this southeastern corner of the Northern Territory is constrained by a limited number of exploration drillholes and 2D seismic coverage (Doig 2022). The Pedirka Basin is prospective for petroleum with several identified plays and has potential for other energy systems at economic depths.
New U-Pb SHRIMP zircon geochronological results from six samples collected from two petroleum exploration drillholes (CBM 107-001 and CBM 107-002) provide maximum deposition age constraints in the Pedirka Basin, the youngest of which support existing palynological age determinations. These new data also provide important provenance and sediment source information for the basin. A dominant Palaeoproterozoic detrital zircon peak ranges from ca 1760– 1740 Ma in all six samples, with younger Neoproterozoic and Cambrian detrital sources also prominent in some units. Part of the Permian succession of the Pedirka Basin is considered to be the lateral equivalent of the main gas producing unit of the Cooper Basin.
The results form part of the developing detrital zircon dataset for the stacked basins of the southeast Northern Territory. Download NTGS Record 2024-003 through GEMIS.