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Eastern Australian hotspots produce the longest continental tracks on Earth (> 2, 000 km). These hotspots are generally assumed to be stationary with respect to one another, an observation reinforced by our analysis. If any motion between them occurred, it is within our 95% uncertainties of 370 km of accumulated motion between hotspots. In contrast, motion between eastern Australian hotspots and the spin axis is indicated by changing paleolatitudes of hotspots through time. Reconstructing Australian hotspot paleolatitudes makes use of the global reference frame established by the geocentric axial dipole hypothesis. The classic paleomagnetic approach to establishing paleolatitude typically uses studies of discrete formations of known age, but the nearly continuous record of volcanism over 34 Ma permit using paleomagnetic data from multiple, different studies that overlap in magnetization age in conjunction. This improves the robustness and precision of our paleolatitude estimates for Eastern Australian hotspot volcanoes. A northward shift of hotspot paleolatitudes between 15-24 Ma of ∼300-1,010 km (95% confidence limits) is observed for volcanoes along the Comboyne, Canobolas and Tasmantid tracks, and for interpolated positions along the Cosgrove and Lord Howe tracks but is significantly resolved only for volcanoes along Comboyne and Canobolas tracks, as well as for two ages from the Stradbroke and Britannia seamounts on the Tasmantid track. Before 24 Ma most data plot to the North of a fixed present day hotspot location in the paleomagnetic reference but 95% confidence limits overlap with it. Notable exceptions are an age from Hillsborough Volcano (Cosgrove Hotspot), and an age from Horse Head (Lord Howe Hotspot) that lie a small distance to the North km, and kmNorth, respectively. Importantly, paleolatitude changes observed along eastern Australian tracks are all explainable by the net rotation of the solid Earth, or true polar wander, with hotspots embedded in the global moving hotspot reference frame.

High-resolution, time-significant correlations are integral to meaningful stratigraphic frameworks in depositional systems but may be difficult to achieve using traditional sequence stratigraphic or biostratigraphic approaches alone, particularly in geologically complex settings. In steep, reefal carbonate margin-to-slope systems, such correlations are essential to unravel shelf-to-basin transitions, characterize strike variability, and develop predictive sequence stratigraphic models-concepts that are currently poorly understood in these heterogeneous settings. The Canning Basin Chronostratigraphy Project integrates multiple independent data sets (including biostratigraphy, magnetostratigraphy, stable isotope chemostratigraphy, and sequence stratigraphy) extracted from Upper Devonian (Frasnian and Famennian) reefal platform exposures along the Lennard Shelf, Canning Basin, Western Australia. These were used to generate a well-constrained stratigraphic framework and shelf-to-basin composite reconstruction of the carbonate system.The resultant integrated framework allows for unprecedented analysis of carbonate margin-to-slope heterogeneity, depositional architecture, and sequence stratigraphy along the Lennard Shelf. Systems tract architecture, facies partitioning, and stacking patterns of margin to lower-slope environments were assessed for six composite-scale sequences that form part of a transgressive-to-regressive supersequence and span the Frasnian-Famennian (F-F) biotic crisis. Variations are apparent in margin styles, foreslope facies proportions, dominant resedimentation processes, downslope contributing sediment factories, and vertical rock successions, related to hierarchical accommodation signals and ecological changes associated with the F-F boundary. We present these results in the form of carbonate margin-to-basin sequence stratigraphic models and associations that link seismicscale architecture to fine-scale facies heterogeneity. These models provide a predictive foundation for characterization of steep-sided flanks of reefal carbonate platform systems that is useful for both industry and academia. This study emphasizes the utility of an integrated stratigraphic approach and the insights gained from better-constrained facies and stratal architecture analysis, insights that were not achievable with traditional sequence stratigraphic or biostratigraphic techniques alone.

We report three high-quality paleomagnetic poles for Oligocene Australia from volcanic provinces along the Cosgrove hot spot track in central Queensland, NE Australia. We present paleomagnetic poles for Springsure (27.3-28.9 Ma: = 300.6 • E, = 70.5 • N, K = 13.7, A 95 = 9.7 • , N = 18∕22, Q = 6), Peak Range (28.2-31.2 Ma: = 291.8 • E, = 64.6 • N, K = 10.1, A 95 = 8.8 • , N = 29∕31, Q = 6), and Hillsborough volcanic provinces (33.1-34.1 Ma: = 301.4 • E, = 67.1 • N, K = 32.2, A 95 = 7.1, N = 14∕18, Q = 7), as well as data from Buckland and Nebo volcanic provinces. Using our new results, we resolve ambiguities present in published paleomagnetic data for Australia during the Oligocene epoch (23-34 Ma) and calculate a combined Oligocene paleomagnetic pole of = 289.2 • E, = 71.0 • N, (K = 24.6, A 95 = 1.9 • , N = 227∕274, Q = 6).We update the continental apparent polar wander path for Australia and find evidence for accelerated seafloor spreading in the Southern Ocean after ∼ 34 Ma (anomaly C13). Lastly, we take advantage of the large number of paleomagnetic sites (N = 97) along the Cosgrove hot spot track to empirically evaluate the TK03.GAD geomagnetic field model. Paleomagnetic directions from rocks along the Cosgrove track have an elongation (E) of 1.6, remarkably consistent with TK03.GAD expected values for hot spot paleolatitudes (E = 1.4-1.6, = 36.6-43.3 • S).