Linking detrital zircon and supercontinent over the past 3 billion years

Abstract

<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>