Full‐plate reconstructions describe the history of past continental motions and how plate boundaries have evolved to accommodate these motions. Traditionally, tectonic reconstructions relied on geophysical data from the oceans and paleomagnetism as the primary quantitative constraints. However, these data do not directly constrain the paths of subduction zones or other plate boundaries, so reconstructing the complete configurations of tectonic plates in the past must rely on alternative methods. Here, we investigate the applicability of detrital zircon age spectra to characterize tectonic settings in deep time using a much larger data set than previously considered. We analyzed the proximity between reconstructed plate boundaries and sample sites assigned to different tectonic categorizations based on the proportion of zircon ages close to the depositional age and found that the categorization has an ∼70% success rate in distinguishing convergent settings. Results are not strongly influenced by factors such as the number of zircon grains available within each detrital sample or uncertainty in the depositional age of the sample. The ability of the categorization to define extensional settings, such as rift basins, is less clear. Nonetheless, the broader pattern of results at the scale of Pangea shows that categorized zircon samples form a coherent pattern, where samples with dominantly young zircons lie at the supercontinent periphery while samples in the core of Pangea are dominated by grains much older than the age of deposition. This result suggests that zircon data could help to quantify uncertainties in full‐plate reconstructions and discriminate between competing models for Proterozoic supercontinents.

<p>The assembly, tenure, and breakup of supercontinents is thought to have played a prominent role in Earth’s plate tectonic history and deeply influenced the paleogeography, crustal deformation, magmatic activity, climate, and biology. To date, at least three supercontinents that once existed on Earth are supported by most geologists. The evolution of Pangea is relatively well-understood, and only a small number of plates are controversial. By contrast, investigations of Rodinia and Nuna have led to many disagreements due to the limited, ambiguous evidence preserved from the Precambrian. Resolving these issues requires the integration of a wide variety of geological data within a quantitative reconstruction framework. In our previous work we linked the reconstruction of Pangea to an extensive global database of detrital zircon samples, demonstrating that samples with different zircon age spectra characteristics help to identify the tectonic setting in which they were deposited – and more broadly, form coherent patterns that delineate the periphery and core of Pangea.</p> <p>Here, we expand on our previous work to investigate the spatial and temporal characteristics of detrital samples deposited over the past 3 Ga. Although the number of available samples becomes more sparse back in time, the distribution patterns of the categorized samples in recent Rodinia reconstructions are nonetheless consistent with previous results for Pangea. General temporal trends reveal that, as supercontinents assemble, the proportion of samples characteristic of subduction tectonic settings increases while the proportion of samples from settings distal from subduction zones decreases, while the opposite trend defines periods of supercontinent dispersal. Together, these results show that quantitative reconstruction of global zircon databases holds important information related to past paleogeographic change.</p>

<p>Reconstructing past episodes of mountain building from the geological rock record is one of the main challenges for unravelling the ancient physical geography of Earth’s surface. Mountains and mountain ranges, often situated at convergent plate margins, play a pivotal role in many fields of the Earth, climate, and biological sciences. Established methods for quantifying past elevations traditionally relied on sedimentary rocks, but in recent years, alternative approaches have emerged on the basis that geochemical signatures of magmatic rocks formed in convergent settings correlate with crustal thickness or elevation. These correlations allow for empirical relations of igneous whole-rock ratios such as La/Yb and Sr/Y with Moho depth for modern convergent settings, which can then be used to estimate ancient crustal thickness or paleoelevation. Since a relatively large number of igneous samples are available for pre-Cenozoic times compared to other paleoelevation proxies, these methods have the potential to allow quantitative mapping of past topographic change for times where existing maps are largely based on a qualitative approach.</p> <p>Here, we investigate the application of paleoelevation estimates derived from geochemistry using the Pacific margin of South America as a case study. We investigate their consistency with independent indicators of past elevations such as stratigraphy, stable isotopes, fossils etc. for Cenozoic samples along the Andean margin. For older times, we compare the estimated paleoelevations with other aspects of the geological record, as well as equivalent values from global paleogeography models widely used in climate modelling studies, to evaluate the extent to which these models are consistent with the igneous geochemical proxies. We derive paleoelevation estimates according to different data filtering schemes, showing that a major consequence of the choice of geochemistry filter is the number of data points left after the filtering. We find that the igneous geochemical proxies yield elevations broadly consistent with traditional results for the Cenozoic, though our results do not resolve some of the rapid uplifts recorded by other proxies. In deeper time, we show that igneous geochemistry quantifies changes in elevation related to documented phases of crustal thickening and thinning, and is thus likely to allow improvements to existing maps of paleotopography. </p>

<p>Full-plate reconstructions describe the history of both past continental motions and how plate boundaries have evolved to accommodate these motions. The fluxes of material into and out of the mantle at plate boundaries is thought to deeply influence the evolution of deep Earth structure, surface environments and biological systems through deep time. Traditionally, plate tectonic reconstructions have relied on geophysical data from the oceans, which provides details of how Pangea broke apart (since ca. 200 Myr) while paleomagnetism is the primary quantitative constraint prior to Pangea formation. However, these data do not directly constrain the extent of subduction zones or other plate boundaries, so reconstructing the past plate configurations of past supercontinents must rely on alternative methods. One source of data that can resolve this problem is to use observations from detrital zircons. Previous studies have proposed classification schemes to determine tectonic settings where samples were deposited, based on the different characteristic shapes of detrital zircon age spectra found in convergent, collisional and extensional settings.</p><p>Here, we investigate the applicability of this method to test and refine global full-plate tectonic reconstructions in deep time, using a published database of zircon ages. We first use reconstructions for relatively recent times (<100 Ma), where reconstructions are reasonable well constrained, to evaluate the effectiveness of the classification method. For older times, where uncertainties in the reconstructions are far larger, we can use the results to discriminate between competing models. We analysed the proximity between reconstructed plate boundaries and zircon sample sites assigned to different tectonic classifications, and found that the classification method does well (~64－79% success depending on distance threshold used) in distinguishing convergent settings. The ability of the classification to define extensional settings such as rift basins is less clear, though samples in this class do lie preferentially further from convergent settings. Based on these insights, we apply the method to evaluate full-plate reconstructions for the Neoproterozoic as well as other competing models for the configuration of Rodinia.</p>