Late Palaeoproterozoic evolution of the buried northern Gawler Craton

- The maximum depositional age of indurated rocks in the northern Gawler are ca. 1780-1740 Ma.
- Minimum depositional ages of deposition in the northern Gawler Craton is tightly constrained by ca. 1731 Ma cross-cutting leucocratic melts.
- These basins developed on a common Neoarchaean substrate across the northern Gawler Craton during the Late Palaeoproterozoic.
- High-grade crustal anatexis attributed to the Kimban Orogeny occurred between ca. 1731 and 1687 Ma.
- Crustal-scale faults in the northern Gawler Craton are unlikely to represent sutures between allochthonous terranes.

This study utilises U-Pb geochronology, Lu-Hf, Sm-Nd isotopes and geochemistry to constrain the timing of deposition, metamorphism and provenance characteristics of buried Palaeoproterozoic meta-sedimentary and meta-igneous rocks in the northern Gawler Craton, Australia. The data suggest that sedimentary sequences were deposited between ca. 1780 and 1740 Ma across a wide region accompanied by syn-depositional magmatism. Restricted zircon age spectra, relatively radiogenic whole-rock Hf-Nd and in-situ zircon Hf isotopic compositions and enriched REE signatures support the notion of a connected series of basins or a single large basin, which developed on a common Neoarchaean substrate across the northern Gawler Craton during the Late Palaeoproterozoic. Temporal and isotopic correlation of these indurated rocks with Palaeoproterozoic basins throughout the North Australian Craton suggests they may form part of an extensive basin system that developed across the Australian continent during the Late Palaeoproterozoic. The meta-sedimentary and meta-igneous rocks of the northern Gawler Craton record high-grade crustal anatexis during the ca. 1730-1690 Ma Kimban Orogeny and subsequent Early Mesoproterozoic re-working.