The Surat Basin is one of a series of shallow intracratonic basins that comprise the Great Australian Superbasin and developed in response to the initiation of Gondwanan breakup. Within the Surat Basin, the Walloon Coal Measures (WCM) are a significant target for Coal Seam Gas (CSG) production and the identification of the boundary with the overlying Springbok Sandstone (SST) is critical to the stratigraphic framework of the basin, and identification of groundwater flow units it delineates. Identification of the contact on a local (tenement) and regional (basin) scale between the SST and WCM is challenged in CSG producing areas by (i) overall lithological similarity of the units (macro-and microscopically, whole rock geochemistry, wireline signature), (ii) lateral heterogeneity of lithologies on a regional scale due to lateral facies and depositional environment variation in the uppermost WCM and lowermost SST and (iii) lack of consistent regional stratigraphic markers like erosion surfaces or correlated tuff beds. Sediment provenance analysis via detrital zircon (DZ) U-Pb geochronology allows constraint of spatial and tempo-ral changes in sediment provenance by sampling across stratigraphic units along a lateral transect. The resulting large-scale stratigraphic correlations facilitate identification of basin dynamics within a tecton-ically quiescent basin. Here we present the results of DZ distributions from 26 samples that were sampled from four wells along a 300 km transect from the eastern Eromanga Basin to easternmost extent of the Surat Basin. Our data show a brief pulse of basement derived material at the base of the SST which inter-rupts the predominant volcaniclastic sediment provenance in the SST and WCM. This brief change in zir-con provenance is interpreted as a precursor to higher energy depositional environments in the SST and can be utilised as a regional marker across the Surat and Eromanga basins, indicating a change in source provenance and basin dynamics associated with the SST - WCM boundary.(c) 2023 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

The Devonian represents a period of transition for the accretionary orogens of the Australian Tasmanides where the largest and inboard Thomson Orogen became stabilised and orogenic processes became focused in the outboard and newly developing New England Orogen. The end of tectonic activity in the Thomson and the adjacent Delamerian and Lachlan orogens culminated with the development of sev-eral overlying intracratonic sedimentary basins. We examine the two largest cover basins, the Adavale and Darling, using stratigraphic logging, sandstone petrography, detrital zircon and rutile U-Pb geochronology to fingerprint sediment sources to test whether the basins were once connected and part of a much larger cover basin system. Sediment provenance in the Adavale Basin is characterised by (i) continuous input from a basement-derived Ordovician (-480 Ma) igneous zircon source, (ii) reworking of metasedimentary basement rocks with a 'Pacific-Gondwana' age signature (iii) reworking of detrital rutile from Cambro-Ordovician sedimentary rocks in the Thomson Orogen ultimately sourced from the Musgrave Block and (iv) an addition of syn-depositional volcanic zircon from contemporary volcanism between-380 and 360 Ma. Sediment provenance of the Darling Basin is dominated by reworking of (meta)sedimentary basement, evident from large proportions of rounded zircons exhibiting a 'Pacific -Gondwana' age signature and detrital rutile with Peterman Orogeny ages. A much less significant age population of syn-depositional volcanic detrital zircons suggests input from contemporary volcanic sources which were more distal and extra-basinal.The comparison of sandstone compositions and detrital age information indicate both basins record similar provenance signals in terms of reworking of their respective hinterlands and receiving contribu-tions from relatively distal syn-depositional volcanism. However, the comparison of sediment prove-nance proxies, suggests that the Adavale and Darling basins were not connected during the Devonian and that the basins are intracratonic or cover basins, recording the stabilisation of the Thomson and Lachlan orogens, respectively.(c) 2023 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

The Devonian subsurface Adavale Basin occupies a central position in the Paleozoic central Thomson Orogen of eastern Australia and records its tectonic setting during this time interval. Here, we have focussed on the basal volcanics of the Gumbardo Formation to clarify the tectonic setting of the basin. The approach has been to undertake stratigraphic logging, LA-ICP-MS U–Pb zircon geochronology and whole-rock geochemical analysis. The data indicate that basin initiation was rapid occurring at ca 401 Ma. The volcanic rocks are dominated by K-feldspar phyric rhyodacitic ignimbrites. The whole-rock geochemical data indicate little evidence for extensive fractional crystallisation, with the volcanic suite resembling the composition of the upper continental crust and exhibiting transitional I- to A-type tectonomagmatic affinities. One new U–Pb zircon age revealed an Early Ordovician emplacement age for a volcanic rock previously interpreted to be part of the Early Devonian Gumbardo Formation, and older basement age is consistent with seismic interpretations of uplifted basement in this region of the western Adavale Basin. Five ignimbrites dated from different stratigraphic levels within the formation yield similar emplacement ages with a pooled weighted age of 398.2 ± 1.9 Ma (mean square weighted deviation = 0.94, n = 93). Significant zircon inheritance in the volcanic rocks records reworking of Ordovician and Silurian silicic igneous basement from the Thomson Orogen and provides insight into the crustal make-up of the Thomson Orogen. Collectively, the new data presented here suggest the Adavale Basin is a cover-type basin that developed on a stabilised Thomson Orogen after the major Bindian deformation event in the late Silurian.