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Neoproterozoic tectonic geography was dominated by the formation of the supercontinent Rodinia, its break-up and the subsequent amalgamation of Gondwana. The Neoproterozoic was a tumultuous time of Earth history, with large climatic variations, the emergence of complex life and a series of continent-building orogenies of a scale not repeated until the Cenozoic. Here we synthesise available geological and palaeomagnetic data and build the first full-plate, topological model of the Neoproterozoic that maps the evolution of the tectonic plate configurations during this time. Topological models trace evolving plate boundaries and facilitate the evaluation of “plate tectonic rules” such as subduction zone migration through time when building plate models. There is a rich history of subduction zone proxies preserved in the Neoproterozoic geological record, providing good evidence for the existence of continent-margin and intra-oceanic subduction zones through time. These are preserved either as volcanic arc protoliths accreted in continent-continent, or continent-arc collisions, or as the detritus of these volcanic arcs preserved in successor basins. Despite this, we find that the model presented here still predicts less subduction (ca. 90%) than on the modern earth, suggesting that we have produced a conservative model and are likely underestimating the amount of subduction, either due to a simplification of tectonically complex areas, or because of the absence of preservation in the geological record (e.g. ocean-ocean convergence). Furthermore, the reconstruction of plate boundary geometries provides constraints for global-scale earth system parameters, such as the role of volcanism or ridge production on the planet's icehouse climatic excursion during the Cryogenian. Besides modelling plate boundaries, our model presents some notable departures from previous Rodinia models. We omit India and South China from Rodinia completely, due to long-lived subduction preserved on margins of India and conflicting palaeomagnetic data for the Cryogenian, such that these two cratons act as ‘lonely wanderers’ for much of the Neoproterozoic. We also introduce a Tonian-Cryogenian aged rotation of the Congo-São Francisco Craton relative to Rodinia to better fit palaeomagnetic data and account for thick passive margin sediments along its southern margin during the Tonian. The GPlates files of the model are released to the public and it is our expectation that this model can act as a foundation for future model refinements, the testing of alternative models, as well as providing constraints for both geodynamic and palaeoclimate models. [ABSTRACT FROM AUTHOR]

We present results of a paleomagnetic study from Carboniferous forearc basin rocks that occur at both limbs of the Texas Orocline (New England Orogen, eastern Australia). Using thermal and alternating field demagnetizations, two remanence components have been isolated from rocks sampled from the Emu Creek terrane, in the eastern limb of the orocline. A middle-temperature Component M is post-folding and was likely acquired during low-temperature oxidation at 65–35 Ma. A high-temperature Component H is pre-folding, but its comparison with the paleomagnetic data from coeval rocks in the northern Tamworth terrane on the other limb of Texas Orocline does not indicate rotations around a vertical axis, as expected from geological data. A likely explanation for this apparent discrepancy is that Component H postdates the oroclinal bending, but predates folding in late stages of the 265–230 Ma Hunter Bowen Orogeny. The post-Kiaman age of Component H is supported by the presence of an alternating paleomagnetic polarity in the studied rocks. A paleomagnetic study of volcanic and volcaniclastic rocks in the Boomi Creek area (northern Tamworth terrane) revealed a stable high-temperature pre-folding characteristic remanence, which is dated to c. 318 Ma using U–Pb zircon geochronology. The new paleopole (37.8°S, 182.7°E, A 95 = 16.2°) is consistent with previously published poles from coeval rocks from the northern Tamworth terrane. The combination of our new paleomagnetic and geochronological data with previously published results allows us to develop a revised kinematic model of the New England Orogen from 340 Ma to 270 Ma, which compared to the previous model, incorporates a different orientation of the northern Tamworth terrane at 340 Ma. [ABSTRACT FROM AUTHOR]

Orogenic curvatures (oroclines) are common in modern and ancient orogens, but the geodynamic driving forces of many oroclines remain controversial. Here we focus on the New England oroclines of eastern Australia, the formation of which had been previously broadly constrained to the Early–Middle Permian. This time interval encompasses periods of both back-arc extension (at ~ 300–280 Ma) and subsequent contractional deformation (Hunter–Bowen Orogeny) that commenced at ~ 270 Ma along the paleo-Pacific and Gondwanan subduction plate boundary. We present new paleomagnetic data from volcanic rocks that were extruded during the transition from extension to contraction (at ~ 272 Ma), and we show that the oroclinal structure must have formed prior to the emplacement of the volcanic rocks. Our results thus indicate that oroclinal bending in the southernmost New England Orogen has been completed prior to the onset of Middle Permian contractional deformation. It is therefore concluded that the oroclines have likely formed during back-arc extension, and that a major contribution to the orogenic curvature was driven by trench retreat. [ABSTRACT FROM AUTHOR]

Critical assessment of Paleozoic paleomagnetic results from Australia shows that paleopoles from locations on the main craton and in the various terranes of the Tasman Fold Belt of eastern Australia follow the same path since 400 Ma for the Lachlan and Thomson superterranes, but not until 250 Ma or younger for the New England superterrane. Most of the paleopoles from the Tasman Fold Belt are derived from the Lolworth-Ravenswood terrane of the Thomson superterrane and the Molong-Monaro terrane of the Lachlan superterrane. Consideration of the paleomagnetic data and geological constraints suggests that these terranes were amalgamated with cratonic Australia by the late Early Devonian. The Lolworth-Ravenswood terrane is interpreted to have undergone a 90° clockwise rotation between 425 and 380 Ma. Although the Tamworth terrane of the western New England superterrane is thought to have amalgamated with the Lachlan superterrane by the Late Carboniferous, geological syntheses suggest that movements between these regions may have persisted until the Middle Triassic. This view is supported by the available paleomagnetic data. With these constraints, an apparent polar wander path for Gondwana during the Paleozoic has been constructed after review of the Gondwana paleomagnetic data. The drift history of Gondwana with respect to Laurentia and Baltica during the Paleozoic is shown in a series of paleogeographic maps. [Copyright &y& Elsevier]

After its Ediacaran-Early Cambrian assembly, Gondwana was flanked by a system of peripheral orogens, Terra Australis, Avalonian-Cadomian and newly defined North Indo-Australie, which display broad temporal correlations of their lithotectonic records. Prior to assembly, their initial histories were primarily controlled by the early Neoproterozoic breakup of Rodinia with second order variances reflecting the differing relationships of their basement continental blocks to that supercontinent. The Terra Australis Orogen developed on basement blocks that previously occupied interior locations within Rodinia and initial successions record development of a passive continental margin. The North Indo-Australie orogen records a similar history of passive margin development, but at least its Indian portion was likely separate from Rodinia. The basement blocks of the Avalonian-Cadomian Orogen previously occupied exterior locations around Rodinia with initial successions indicating the development of a convergent plate margin. As Gondwana assembled, Avalonian-Cadomian convergence terminated at about the same time as convergence commenced in the Terra Australis and North Indo-Australie orogens. The absence of a complete long-lived contemporaneous subduction girdle around Gondwana likely prevented its breakup, in contrast to Rodinia and Pangea, in which the presence of subduction girdles corresponds with lithospheric extension across the supercontinents as a precursor to their ultimate breakup. • Gondwana flanked by a system of peripheral orogens: Terra Australis, Avalonian-Cadomian and North Indo-Australie. • Initial histories of the orogens primarily controlled by the early Neoproterozoic breakup of Rodinia. • Major events within each orogen display temporal and kinematic linkages to events in adjoining orogens. • Failure of Gondwana to breakup due to absence of long-lived subduction girdle around its periphery. [ABSTRACT FROM AUTHOR]