Linking the Gawler Craton and Mount Isa Province through hydrothermal systems in the Peake and Denison Domain, northeastern Gawler Craton

Abstract

Tectonic reconstructions of Proterozoic Australia commonly place the Peake and Denison Domain of the northeastern Gawler Craton at the interface between the North and South Australian cratons prior to the reconfiguration of Australia’s main tectonic components in the Mesoproterozoic. However, this reconstruction is largely based on palaeomagnetic data as the geological correlations between these regions are currently limited, particularly during the Mesoproterozoic. The early Mesoproterozoic period is significant as it corresponds to major IOCG mineralization in the eastern Gawler Craton between 1600 Ma and 1575 Ma, and IOCG mineralization in the Mount Isa Province largely between 1550 Ma and 1490 Ma. Therefore, determining the relationship of the Peake and Denison Domain to the Gawler Craton and Mount Isa Province during this period is essential to evaluating mineral prospectivity in the northeastern Gawler Craton. New U–Pb LA-ICP-MS geochronology on zircon and titanite improves our understanding of the tectonothermal and hydrothermal history the Peake and Denison Domain during the latePalaeoproterozoic, early-Mesoproterozoic and the Cambrian–Ordovician periods. Titanite formed within largely calc-silicate alteration assemblages indicates the Peake and Denison Domain has a protracted history of hydrothermal activity, recording events at c. 1565 Ma, 1530–1515 Ma, c. 1500 Ma, c. 1465 Ma and c. 490 Ma. The highly calcic nature of the c. 1565–1500 Ma alteration in the Peake and Denison Domain shares strong similarities in age and character to the regional calcic-sodic alteration recorded in the Mount Isa Province. We suggest the two regions were influenced by similar hydrothermal systems during the early Mesoproterozoic, supporting reconstruction models that place the Peake and Denison Domain near the Mount Isa Province during the early-Mesoproterozoic. This highlights the prospectivity of the Peake and Denison Domain for Isan-style IOCG mineralization, but requires consideration of the post-1500 Ma rotation of prospective structures.