New SHRIMP U–Pb zircon geochronology for volcanic and volcaniclastic sedimentary rocks from the central Pine Creek Orogen provides constraints on the Palaeoproterozoic evolution of northern Australia. An intermediate agglomerate from the Stag Creek Volcanics (Namoona Group) and two samples of volcaniclastic sedimentary rock from the Wildman Siltstone (Mount Partridge Group) were dated to constrain the age of the lower parts of the Palaeoproterozoic succession. These samples all have a youngest zircon population with an age in the range ca. 2030–2020 Ma, which is interpreted to approximate the age of volcanism and volcaniclastic deposition. Two widely separated samples of Gerowie Tuff from the overlying South Alligator Group have depositional ages of 1864 ± 3 Ma and 1862 ± 4 Ma. Zircons of the Berinka Volcanics and Warrs Volcanic Member within the overlying Finniss River Group have crystallisation ages of 1861 ± 4 Ma and 1862 ± 3 Ma, respectively. These new data suggest that the basal units of the Pine Creek Orogen were being deposited in part during a previously unrecognised episode of ca. 2030–2020 Ma felsic volcanism and sedimentation in northern Australia, which was followed by a major hiatus. The ca. 1865–1860 Ma ages for volcanic rocks within the South Alligator and Finniss River Groups provide a maximum age on the timing of deformation and metamorphism in the central Pine Creek Orogen, and allow correlation with felsic volcanic events across large areas of the Pine Creek Orogen and the North Australian Craton.

The Palaeoproterozoic Pine Creek Orogen, northern Australia, forms part of the North Australia Craton, and is a highly prospective terrain, with abundant mineral occurrences including gold and uranium. Geologically, it comprises sedimentary sequences deposited on rifted Archaean basement that were deformed, metamorphosed, and intruded by granitoids and mafic bodies during the ca. 1880-1850 Ma Nimbuwah Event, one of the constituent events of the Barramundi Orogeny.The stratigraphy of the central Pine Creek Orogen is well-characterised due to its extensive exposure, preservation, and low grade greenschist facies metamorphism. It contains units suitable for isotopie dating, permitting determination of absolute ages within a well-controlled stratigraphic framework. We present new zircon U-Pb SHRIMP results for volcanics and volcanogenic strata from various intervals within the pre-orogenic stratigraphy. These data: (a) indicate the presence of volcanic activity in the Pine Creek Orogen at ca. 2025 Ma; (b) provide revised constraints on the tectono-thermal evolution of the Pine Creek Orogen, specifically a revision of the Nimbuwah Event by some 20 Ma; (c) suggest that volcanism was widespread across the Pine Creek Orogen at ca. 1860 Ma; and (d) permit assessment of relative deposition rates of and time intervals between deposition of the Palaeoproterozoic stratigraphic sequences.