What question did this study set out to answer?

To compile and standardize geochronological data for geological units in South Australia.

February 2, 2026Open Access

Isotopic Atlas of Australia: Geochronology compilation for South Australia. Version 1.0

Key Points

To compile and standardize geochronological data for geological units in South Australia.
Compiled 1,101 radiometric ages from various sources including SHRIMP datasets and technical reports.
Utilized borehole (539) and outcrop (562) samples for data collection.
Analyzed geological events such as igneous crystallisation, metamorphism, and mineralisation.
Dominant age range identified during the Proterozoic epoch (~1800–1550 Ma).
A secondary age peak noted in the early Paleozoic (~550–400 Ma) linked to the Delamerian Orogeny.
Compilation focused on the Gawler Craton while highlighting the need for broader coverage in future updates.

Abstract

This Record presents the first version of a South Australia (SA) geochronology compilation developed as part of Geoscience Australia’s Isotopic Atlas of Australia, which commenced under the Exploring for the Future (EFTF) program and continues to support the objectives of the Resourcing Australia’s Prosperity initiative (RAPi). The compilation brings together 1,101 interpreted radiometric ages for geological units across South Australia, derived from Geoscience Australia’s Sensitive High Resolution Ion Microprobe (SHRIMP) datasets, Geological Survey of South Australia technical reports, peer-reviewed literature and academic theses. While non-exhaustive, the compilation provides a consistent and standardised framework for examining the timing of geological processes across the State. Completion of the SA compilation represents a significant milestone for the Isotopic Atlas, achieving continent-wide coverage of interpreted geochronological data.Ages in the SA compilation are derived from both borehole samples (539) and outcrop samples (562), supporting regional-scale geological synthesis. The dataset spans a broad temporal range from the Paleoarchean to the Cenozoic (~3250 to 2.2 Ma), reflecting the long and episodic geological evolution of South Australia. It is dominated by U–Pb geochronology, with fewer contributions from Rb–Sr, Sm–Nd, K–Ar, Ar–Ar and Re–Os systems. Recorded geological events include igneous crystallisation, metamorphism, deposition, hydrothermal activity, cooling, deformation, mineralisation and isotopic resetting. Temporal analysis highlights a dominant Proterozoic concentration of igneous crystallisation ages (~1800–1550 Ma), consistent with major tectono-magmatic events in South Australia, particularly within the Gawler Craton, and a smaller early Paleozoic peak (~550–400 Ma) associated with the Delamerian Orogeny. The compilation is spatially biased toward the Gawler Craton, and interpretations are therefore weighted toward its geological history; improved coverage of other provinces and isotopic systems is anticipated in future updates.The SA geochronology compilation is accessible via the Geoscience Australia Data Portal, GA Web Services and a static snapshot associated with this Record, supporting interactive analysis, flexible data download and GIS integration. This first-pass compilation establishes a robust foundation for temporal geological analysis and provides a framework for the ongoing expansion and refinement of South Australia’s geochronological record.

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