Record 2026-001 presents new Sensitive High Resolution Ion Microprobe (SHRIMP) U-Pb geochronological results from the eastern Amadeus Basin. These results were obtained from outcrop samples as part of the joint 2024-25 Northern Territory Geological Survey-Geoscience Australia (NTGS-GA) geochronology project under the National Collaboration Framework (NCF) agreement. Ten samples were selected to investigate zircon provenance of Neoproterozoic to Devonian strata of the Amadeus Basin and to aid reassignment of sedimentary units as part of NTGS's mapping activities in the eastern part of the basin.
Across most formations, zircon populations show a progressive up-section increase in 1200–1000 Ma detritus and a decline in 1800–1600 Ma grains. This pattern reflects shifting sediment pathways and changing provenance through the Neoproterozoic–Palaeozoic stratigraphy of the Amadeus Basin. The Devonian Idracowra Sandstone stands out as an exception to this pattern, as it returns to a detrital zircon signature dominated by Palaeoproterozoic grains. The shift in detrital zircon population observed in the Idracowra Sandstone may reflect a change in provenance during the Alice Springs Orogeny.
These new SHRIMP U–Pb results refine maximum depositional ages, support stratigraphic reassignment on the RODINGA 1:250 000 mapsheet and expand the regional detrital zircon database. This database is useful for tracking sediment pathways and reconstructing basin evolution. The new dataset strengthens the geological framework underpinning NTGS’s ongoing mapping and resource assessment programs.
The full record, Summary of results. Joint NTGS–GA geochronology project: selected samples from RODINGA 1:250 000 mapsheet, Amadeus Basin, is available via GEMIS